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EK-V13XX-TP-001 



VT330/VT340 

Programmer Reference Manual 
Volume 1: Text Programming 





USER'S INFORMATION MAP 



Installing and Using 
The VT330/VT340 Video Terminal 



VT330/VT340 
Programmer Reference Manual 



Install and set 
up the terminal 




Chapters 
2 and 3 










Run dual 
sessions 




Chapters 
3 and 8 










Use the 
Set-Up screens 




Chapter 
5 










Compose 
characters 




Chapter 
6 










Define 
function keys 




Chapter 
7 










Print data on 
a local printer 




Chapter 
11 










Use a modem 




Chapter 
11 










Learn to program 
the terminal 




Appendix 
C 










Solve problems 
and get service 




Chapters 
2 and 12 





Learn about 
character 
encoding 




Volume 1, 
Chapter 2 









Find the 
code tables 
for 
character sets 



Program the 

terminal ' s 

text features 



Volume 1, 
Chapter 2 



Volume 1 
Chapters 
3 to 13 



Program the 

terminal 's 

graphics 

features 




Volume 2 









^-003 {ps^/as 

EK-VT3XX-TP-001 

VT330/VT340 

Programmer Reference Manual 
Volume 1: Text Programming 



Prepared by Educational Services 

of 

Digital Equipment Corporation 



1st Edition, March 1987 

Copyright © 1987 by Digital Equipment Corporation. 
All Rights Reserved. 
Printed in Taiwan. 

The reproduction of this material, in part or whole, is strictly prohibited. For 
copy information, contact the Educational Services Department, Digital 
Equipment Corporation, Maynard, Massachusetts 01753. 

The information in this document is subject to change without notice. Digital 
Equipment Corporation assumes no responsibility for any errors that may ap- 
pear in this document. 

AT&T is a trademark of American Telephone and Telegraph Company. 
Tek and Tektronix are trademarks of Tektronix, Inc. 
Vadic is a trademark of Racal-Vadic. 

The following are trademarks of Digital Equipment Corporation, Maynard, 
Massachusetts. 



DEC 

DECconnect 

DECmate 

DECnet 

DECpage 

DECserver 

DECsystem-10 

DECSYSTEM-20 

DECtalk 



DECUS 
DECwriter 
DIBOL 
LA12, LA36 
LA50, LA75 
LA100, LA120 
LA210 
LN01, LN03 



MicroVAX 

MicroVMS 

PDP 

P/OS 

Professional 

Rainbow 

ReGIS 

RSTS 



LQP02, LQP03 RSX 



SSU 

UNIBUS 

VAX 

VMS 

VT 

VT52, VT100, VT101, VT102 

VT125, VT131, VT220, VT240 

VT330, VT340 

Work Processor 



This manual was prepared using DECpage V2.0 software and other in-house 
documentation software. 



CONTENTS 



ABOUT THIS MANUAL • ix 

PART 1 INTRODUCTION TO YOUR VT330/VT340 
TERMINAL 

CHAPTER 1 VT300 FEATURES • 3 

The VT330/VT340 Terminal, 3 
New Features, 5 
General Features, 7 
Operating States, 10 
Operating Modes, 10 

CHAPTER 2 CHARACTER ENCODING • 12 

Coding Standards, 13 

Characters and Character Sets, 15 

Code Table, 15 

VT300 Character Sets, 20 

Control Characters, 28 

Control Functions, 34 

Working with 7-Bit and 8-Bit Environments, 40 

Display Controls Mode, 41 

PART 2 CONTROL FUNCTIONS SENT TO THE HOST 

CHAPTER 3 KEYBOARD CODES • 47 

Keyboard Codes, 47 
Special Cases, 58 

CONTENTS Hi 



PART 3 CONTROL FUNCTIONS RECEIVED FROM THE 
HOST 

CHAPTER 4 EMULATING VT SERIES TERMINALS • 65 

Level 1 (VT100 mode), 66 

Level 3 (VT300 mode), 66 

All Levels, 66 

Selecting an Operating Level, 68 

Sending Cl Controls to the Host, 69 

National Replacement Character Set Mode (DECNRCM), 70 

CHAPTER 5 USING CHARACTER SETS • 71 

Selecting Character Sets (SCS), 72 
Soft Character Sets, 82 

CHAPTER 6 PAGE MEMORY • 102 

What is Page Memory?, 103 
Controlling the Page Format, 106 
Moving to Another Page, 109 
Summary, 111 

CHAPTER 7 SETTING VISUAL CHARACTER AND LINE 
ATTRIBUTES • 114 

Setting Visual Character Attributes, 114 
Setting Line Attributes, 116 
Summary, 117 

CHAPTER 8 EDITING AND CHARACTER PROTECTION • 118 

Editing, 119 

Character Protection, 126 
Independent Protection. 126 
Visual Attribute Protection, 129 
Summary, 131 

CHAPTER 9 LOCAL EDITING • 134 

How Local Editing Works, 135 

Selecting Edit Mode, 136 

Defining the Size of the Character Block, 137 

Selecting the Characters to Send. 141 

End-of-Block and Unused Space Characters, 144 

iv CONTENTS 



Sending Edited Data to the Host, 148 
Block Transmission Examples, 149 
Character Sets and Block Transmission, 153 
Summary, 156 

CHAPTER 10 CURSOR MOVEMENT AND PANNING • 159 

The Cursor, 161 

Moving the Cursor on the Current Page. 161 

Panning, 163 

Cursor Coupling, 164 

Summary, 167 

CHAPTER 11 KEYBOARD, PRINTING, AND DISPLAY 
COMMANDS • 169 

Keyboard Control Functions, 170 
User-Defined Keys (DECUDK), 175 
Printer Port Control Functions, 181 
Printing Functions, 182 
Printing Visual Attributes, 185 
Screen Display Control Functions, 186 
Summary, 190 

CHAPTER 12 VT300 REPORTS • 195 

Device Attributes (DA), 196 

Terminal Identification (DECID), 200 

Device Status Reports (DSR), 201 

Terminal State Reports, 205 

Presentation State Reports, 209 

Mode Settings, 218 

Control Function Settings, 225 

Saving and Restoring the Cursor State, 229 

Window Reports, 230 

User-Preferred Supplemental Set, 231 

Summary, 233 

CHAPTER 13 RESETTING THE TERMINAL • 241 

Soft Terminal Reset, 242 
Hard Terminal Reset, 244 
Tab Clear, 245 
Summary, 241 



CONTENTS v 



PART 4 DUAL SESSIONS 

CHAPTER 14 SESSION MANAGEMENT • 249 

Dual Sessions, 249 

Two Ways to Manage Sessions, 250 

Session Resources, 252 

Multiple System Communications (MSC), 254 

Session Support Utility, 254 

Selecting Sessions (MSC or SSU Software), 255 

APPENDIX A VT52 MODE CONTROL CODES • 257 

Entering VT52 Mode, 257 
Exiting VT52 Mode, 258 

APPENDIX B COMMUNICATIONS • 259 

Character Format, 260 

Making Connections, 260 

Communicating with Non-Digital Systems. 261 

VT300 Communication Ports, 265 

Modems, 271 

Communications Set-Up Screen, 272 

Flow Control Features, 272 

Character Format Features, 274 

Modem Features, 275 

Break, 279 

Standards and Certification, 280 

GLOSSARY • 285 

INDEX OF CONTROL FUNCTIONS • 303 

GENERAL INDEX • 321 

FIGURES 

1-1 VT330/VT340 Video Display Terminal, 4 

2-1 7-Bit ASCII Code Table, 1 7 

2-2 7-Bit Code, 17 

2-3 8-Bit Code Table, 19 

2-4 8-Bit Code, 19 



vi CONTENTS 



2-5 DEC Multinational Character Set, 21 

2-6 ISO Latin Nr 1 Supplemental Character Set, 23 

2-7 DEC Special Graphic Character Set, 26 

2-8 DEC Technical Character Set, 27 

2-9 Display Controls Font, 42 

3-1 Four Key Groups (North American/U.K. Keyboard). 48 

3-2 Standard Key with a Data Processing Character, 49 

5-1 Character Set Selection, 73 

5-2 Designating and Mapping Character Sets in VT100 Mode, 76 

5-3 Designating and Mapping Character Sets in VT300 Mode, 77 

5-4 Character Cell Sizes for 80- and 132-Column Fonts, 83 

5-5 Character Body Sizes for 80- and 132-Column Fonts, 84 

5-6 Example of an Uppercase D in an 80-Column Font, 85 

5-7 Sixel-to-ASCII Conversion, 89 

6-1 A Page in Page Memory, 103 

6-2 Page Sizes for a Single Session, 104 

6-3 Page Sizes for Dual Sessions, 105 

9-1 Sending Data in Edit Mode, 150 

10-1 The Difference Between Scrolling and Panning, 160 

14-1 Typical MSC Environments, 251 

14-2 Typical SSU Environment, 252 

TABLES 

2-1 National Replacement Character Sets, 25 

2-2 CO (7-Bit) Control Characters Recognized, 28 

2-3 CI (8-Bit) Control Characters Recognized, 31 

2-4 8-Bit Control Characters and Their 7-Bit Equivalents, 32 

3-1 Codes Sent by Editing Keys, 51 

3-2 Codes Sent by Arrow Keys, 52 

3-3 Codes Sent by Numeric Keypad Keys, 53 

3-4 Codes Sent by the Top-Row Function Keys, 55 

3-5 Keys Used to Send 7-Bit Control Characters, 57 

3-6 Keys Affected by Local Editing Mode, 58 

4-1 Control Functions Ignored in Level 1 (VT100 mode), 67 

5-1 Character Sets Available, 72 

5-2 Designating Character Sets, 74 

5-3 Mapping Character Sets with Locking Shifts, 78 



CONTENTS vii 



5-4 Guidelines for Designing Soft Characters, 83 

5-5 Converting Binary Code to an ASCII Character, 87 

5-6 DECDLD Parameter Characters, 92 

5-7 Valid DECDLD Parameter Combinations, 96 

6-1 Page Format Sequences, 112 

6-2 Sequences for Moving Through Page Memory, 113 

7-1 Visual Character Attribute Values, 115 

7-2 Character and Line Attribute Sequences, 117 

8-1 Control Functions Affected by Character Protection, 119 

8-2 Editing Sequences, 131 

8-3 Character Protection Sequences, 133 

9-1 Defining the Character Block Size for Transmission, 138 

9-2 Selecting Character Fields for Transmission, 141 

9-3 Local Editing Sequences, 156 

10-1 Cursor Movement and Panning Sequences, 167 

11-1 Keyboard Control Sequences. 191 

11-2 Programming UDKs, 192 

11-3 Printing Control Sequences, 193 

11-4 Screen Display Control Sequences, 194 

12-1 Alias Primary DA Responses from the VT300, 199 

12-2 ANSI Modes for DECRQM, DECRPM. SM and RM, 220 

12-3 DEC Private Modes for DECRQM. DECRPM, SM and RM, 220 

12-4 Control Functions for DECRQSS REquests, 226 

12-5 Sequences for VT300 Reports, 233 

13-1 Soft Terminal Reset (DECSTR) States. 242 

13-2 VT300 Reset Sequences, 246 

A-l VT52 Escape Sequences, 258 

B-l Cables to Terminal Servers, Modems, and Statistical Multiplexers, 263 

B-2 Cables to Digital Printers 

B-3 EIA Interface Signals for the 25-Pin RS232 Connector, 266 

B-4 Common Speed Settings for Modems, 269 

B-5 Worldwide Modem Protocols, 272 



viii CONTENTS 



ABOUT THIS MANUAL 



This reference manual is for people with a general knowledge of computer pro- 
gramming. If you are a programmer, this manual provides the information you 
need to program the text features of your VT330 or VT340 terminal. Volume 2 
covers graphics programming features. The VT330 is a text and monochrome 
graphics terminal. The VT340 is a text and color graphics terminal. 

This manual is part of the VT300 user documentation package. Each manual in 
the package is for a certain audience. 

• Installing and Using the VT330/VT340 Video Terminal 
For the installer and general user 

• VT330/VT340 Programmer Reference Manual 
Programmers writing applications for the VT330/VT340 

Volume 1 Text applications 

Volume 2 Graphics applications 

Pocket Guide Summary of volumes 1 and 2 

ORGANIZATION 

The manual is divided into four parts. 

Part 1, Introduction to Your VT300 Terminal 

covers the information you need to know before you begin programming the 

terminal. 

• Chapter 1, "VT300 Features," provides an overview of the terminal. 
The chapter briefly describes the terminal's major features and oper- 
ating modes. 



IX 



• Chapter 2, "Character Encoding," describes the character-encoding 
concepts used when the VT300 operates as a text terminal. The 
chapter also describes the terminal's character sets, and control 
function format. 

Part 2, Control Functions Sent to the Host 
covers the codes sent from the keyboard. 

• Chapter 3, "Keyboard Codes," describes the characters and control 
functions that the terminal sends to the host. 

Part 3, Control Functions Received from the Host 

covers all the control functions you can use to program the terminal. 

• Chapter 4, "Emulating VT Series Terminals," describes the control 
functions used to emulate Digital's other VT series terminals. 

• Chapter 5, "Using Character Sets," describes the control functions 
used to select the terminal's built-in character sets and your own 
soft character sets. 

• Chapter 6, "Page Memory," describes the control functions used to 
format and move through the terminal's page memory. 

• Chapter 7, "Setting Visual Character and Line Attributes," de- 
scribes the control functions used to highlight text, such as holding 
and underlining. 

• Chapter 8, "Editing and Character Protection," describes the control 
functions used to edit or protect characters in the terminal's page 
memory. 

• Chapter 9, "Local Editing," describes the control functions that let 
the terminal perform local editing tasks. To use this feature, your 
host system must support local editing. 

• Chapter 10, "Cursor Movement and Panning," describes the control 
functions used to move the cursor and pan through data in page 
memory. 

• Chapter 11, "Keyboard, Printing, and Display Commands," de- 
scribes the control functions used to program the terminal's key- 
board, printer port, and display screen. 



x ABOUT THIS MANUAL 



• Chapter 12, "VT300 Reports," describes the control functions used 
to request reports on the operating state of the terminal. The chap- 
ter also describes the format of the reports sent by the terminal, 
and the control functions use to restore the terminal to a previous 
state. 

• Chapter 13, "Resetting the Terminal," describes the control func- 
tions used to reset the terminal's operating features to factory- 
default or saved settings. 

Part 4, Dual Sessions 

describes two methods for managing sessions on the VT300. 

• Chapter 14, "Session Management," describes the commands used 
to control the terminal's dual-session capability. You can use 
Digital's SSU software to run dual sessions over a single communi- 
cation line. 

Appendix A, "VT52 Mode Control Codes," describes control functions used 
when the terminal is in VT52 mode. 

Appendix B, "Communication," describes how the terminal communicates with 
the host system and local devices, such as modems and printers. The appendix 
also describes how to connect to non-Digital systems and provides cabling 
information. 

Appendix C, "Compatibility with Other Digital Terminals," compares the 
VT330 and VT340 terminals to other VT series terminals. 

CONVENTIONS USED IN THIS MANUAL 

• This manual uses the term VT300 when describing features common 
to the VT330 and VT340 terminals. 

• Notes and programming tips appear throughout this manual. 

— Notes provide general operating information. 

— Programming tips provide helpful suggestions to consider when 
writing applications. 

• Set-up features and keyboard keys appear in bold type. 
Examples 

Press the Return key. 



ABOUT THIS MANUAL xi 



Use the Clear Communications feature in the Set-Up Directory 
screen. 

Characters used in control functions appear in bold type. Below each 
character is a column/row number that indicates the character's po- 
sition in a standard code table. 

Example 

ESC #6 <— Control function 

1/11 2/3 3/6 <— Column/row numbers 

Glossary entries appear in italics when first used in text. 

Example 

The VT300 stores information in its page memory. 



xii ABOUT THIS MANUAL 



PART 1 

INTRODUCTION TO YOUR 

VT330/VT340 TERMINAL 



VT300 FEATURES 



1 



The VT330/VT340 Terminal, 3 
New Features, 5 

Dual Sessions, 5 

User Windows, 5 

Page Memory, 6 

Local Editing, 6 

ROM Cartridge Firmware, 7 
General Features, 7 

Set-Up, 7 

Display Features, 7 

Text Features, 8 

Character Sets, 9 

Communication Features, 9 
Operating States, 10 

On-Line, 10 

Local, 10 
Operating Modes, 10 



The VT330/VT340 Terminal 

This chapter provides an overview of the VT330 and VT340 video terminals. 
The chapter briefly describes the major features and operating modes of each 
terminal. Each section tells you where to look in the manual for more informa- 
tion on that feature. 



The VT330 is a monochrome text and graphics terminal. The VT340 is a text 
and color graphics terminal. Each terminal has two major components, a 
monitor/terminal unit and keyboard. The monitor has a tilt-swivel base. See 
Installing and Using the VT330/VT340 Video Terminal for a description of 
these components. 

This manual covers the programming information you need to use the text fea- 
tures for both terminals. Each terminal uses control functions specified by the 
American National Standards Institute (ANSI) and the International 
Organization for Standardization (ISO). Volume 2 covers the graphics features 
for the VT330 and VT340. 

This manual uses the term VT300 when describing features common to all both 
models. The manual only refers to a specific model when a feature is unique to 
that model. Most text features work on both VT300 models. 

Figure 1-1 shows a typical VT300 terminal. The next section describes some of 
the more important new features of the VT300. 




Figure 1-1 VT330/VT340 Video Display Terminal 



4 VT300 FEATURES 



NEW FEATURES 

The VT300 is compatible with Digital's VT220 terminal and offers major new 
features such as dual sessions, user windows, added page memory, and local 
editing. 

Dual Sessions 

When you electronically connect to a host system from your terminal, you start 
an interactive session. The VT300 lets you run two sessions at the same time. 
That is, you can connect to two different jobs on your system. If you connect 
your VT300 to two systems, you can log in to both systems and run those 
sessions at the same time. If you connect your VT300 to a terminal server that 
supports several systems, you can run two sessions, each on a different system. 

The dual sessions feature gives you two terminals in one. The VT300 maintains 
the two sessions separately. You can easily switch back and forth between the 
two sessions by pressing a single key. 

The VT300 has two different methods for managing dual sessions, multiple sys- 
tem communications (MSC) and Digital's Session Support Utility. 

MSC Uses two separate communication lines to maintain two 

sessions at the same. 

SSU software Uses one communication line and Digital's proprietary SSU 
software protocol to maintain two sessions at the same 
time. 

You can select different operating features for each session. For example, you 
can use different set-up selections, page memory format, and user-defined keys. 

For more information on session management, see Chapter 14. 

User Windows 

The VT300 lets you view data from two sessions at the same time. To view 
data from two sessions, you divide the screen into two windows. 

By default, each session you open with a VT300 terminal uses the complete 
screen. This means the terminal can only display data from one session at a 
time. To divide the screen into two windows, you press a sequence of keys. 
Each window is assigned to a session. Information from one session appears in 
one half of the screen, information from the second session appears in the 
other half. 



VT300 FEATURES 5 



You can divide the screen vertically or horizontally. When you divide the screen 
vertically, a border appears down the middle of the screen from line 1 to line 
24. When you divide the screen horizontally, a border appears across the mid- 
dle of the screen from column 1 to the last column. 

For more information on user windows, see Chapter 8 of Installing and Using 
the VT330/VT340 Video Terminal. 

Page Memory 

The VT300 has a multiple-page display memory. This feature lets the terminal 
store more text than appears on the screen. For example, when you use dual 
sessions the terminal can store up to three screen areas of text (three 24-line 
pages) for each session. 

You can select different page sizes. The page sizes available depend on whether 
you are running dual sessions or a single session. 

Dual Sessions 

3 pages of 24 lines x 80 or 132 columns 
2 pages of 36 lines x 80 or 132 columns 
1 page of 72 lines x 80 or 132 columns 



Singi 



e Session 



6 pages of 24 lines x 80 or 132 columns 
4 pages of 32 lines x 80 or 132 columns 
2 pages of 72 lines x 80 or 132 columns 
1 page of 144 lines x 80 or 132 columns 

A page is a section of the terminal's page memory. Each page has left, right, 
top and bottom margins. You can define the size and layout of a page by using 
set-up features or control functions. 

For more information on page memory, see Chapter 6. 

Local Editing 

The VT300 lets you perform local editing, also known as block mode editing. 
However, local editing requires host software support. 

Local editing lets you edit and store data in the terminal, so the host system is 
free to perform other tasks. When you finish editing, you can send the edited 
data to the host in a block. 



VT300 FEATURES 



Local editing mode is compatible with the local editing feature on Digital's 
VT131 terminal, with some added functions. 

For more information on local editing, see Chapter 9. 

ROM Cartridge Firmware 

All firmware for the VT300 is on a ROM cartridge, installed at the rear of the 
terminal. This cartridge must be installed for the terminal to operate. The ter- 
minal comes with the ROM cartridge already installed. 

GENERAL FEATURES 

This section describes the general operating and communication features of the 
VT300. You can set many of these features from the keyboard, using set-up. 

Set-Up 

Set-up is a series of display screens. Each screen lists a group of features, such 
as communications or printing. 

You can use set-up screens to examine and change the current settings for 
features. For example, you can select the keyclick feature, transmit or receive 
speeds, page size, and type of session management. 

The VT300 set-up feature is similar to the VT200 set-up feature. However, the 
VT300 set-up screens have an enhanced format that provides more information 
and is easier to use. Installing and Using the VT330/VT34O Video Terminal 
describes the set-up screens in detail. 

Display Features 

The VT300 screen has the following basic features. 

Monitor VT330: 359 mm (14 inch), flat screen monitor 

VT340: 333 mm (13 inch), conventional color monitor 

Display area 25 lines x 80 or 132 columns 

800 (horizontal) x 500 (vertical) pixels 

Status line on the 25th display line 

Character size For 80 columns: 

9 x 12 pixel body in 10 x 20 character cell 



VT300 FEATURES 7 



For 132 columns: 

5 x 12 pixel body in 6 x 20 character cell 



Bitmap 



VT330: 2 plane (permits 4 shades of gray, out 

of a possible 64) 
VT340: 4 plane (permits 16 shades or colors, 

out of a possible 4096) 



Scrolling 



Horizontal split-screen scrolling on any line boundary 
(same as VT100) 



Text Features 

The VT300 provides a variety of text and editing features. 



Character sets 
(See next 
section.) 

Top-row 
function keys 

Editing 
functions 

Visual 

character 

attributes 

Line 
attributes 

Character 
protection 

styles 

Control 
functions 



5 sets of 94 characters each 

1 set of 96 characters 

Down-line-loadable character set (94 or 96 characters) 

5 local function keys 
15 user-definable keys 

All VT200 editing functions 
Erasure mode 
Local editing 

Normal, bold, underline, blinking, 
reverse video, and invisible characters 

Single-width/single-height lines 
Double-width/single-height lines 
Double-width/double-height lines 

Independent (not based on visual character 
attributes) 

Visual attribute (VT131 style) 

7-bit and 8-bit control characters 
ANSI control functions 
DEC private control functions 
Ability to display control functions 



8 VT300 FEATURES 



Character Sets 

The VT300 has the following built-in character sets. 

ASCII 

DEC Supplemental Graphic 

ISO Latin Alphabet Nr 1 supplemental graphic 

12 National replacement character sets (NRCs) 

DEC Technical 

DEC Special Graphic (VT100 line drawing) 

You can also design a soft character set and load it from the host system into 
the terminal. 

Together, the ASCII and DEC Supplemental Graphic sets make up the DEC 
Multinational character set. When you turn on or reset the terminal, the 
VT300 automatically uses the DEC Multinational set. The ASCII and ISO 
Latin-1 supplemental sets make up the ISO Latin-1 character set. 

Chapter 2 describes the VT300 character sets. Chapter 5 describes how to se- 
lect and use different character sets. 

Communication Features 

The VT300 provides the following features for communicating with the host 
system. 

Character format 7-bit or 8-bit 

Baud rate Asynchronous communication speeds up to 

19. 2K bits per second 

Connectors Two DEC-423 host ports, allowing longer 

distances between the terminal and host(s) 

One RS232-C host port, with a 25-pin 
D-subminiature connector for a host or 
external modem 

One DEC-423 printer port 

One 7-pin micro-DIN connector for a mouse or 
graphic tablet 



VT300 FEATURES 9 



OPERATING STATES 

The VT300 has two major operating states. You select the operating state in 
set-up. 

On-line 
Local 

On-Line 

The on-line state lets the terminal communicate with a host system. The termi- 
nal sends data entered at the keyboard to the host. The terminal displays data 
received from the host on the screen. 

Local 

The local state lets you place the host system on hold. Data entered at the 
keyboard is sent to the screen, but not to the host. The terminal stores data 
received from the host, until you put the terminal back on-line. 

OPERATING MODES 

The VT300 has four major operating modes for text operations. You can select 
each mode from the keyboard via set-up, or from the host via control codes. 
The VT300 uses standard ANSI functions in all operating modes, except VT52 
mode. 

VT300 mode, 7-bit controls (default) 
VT300 mode, 8-bit controls 
VT100 mode 
VT52 mode 

VT300 mode, 7-bit controls is the default operating mode. This mode provides 
the full range of VT300 capabilities, using 8-bit characters and 7-bit control 
characters. All character sets are available. This mode provides full compatibil- 
ity with Digital's VT200 series terminals. Digital recommends this mode for 
most applications. 

VT300 mode, 8-bit controls provides the full range of VT300 capabilities, using 
8-bit characters and 8-bit control characters. All character sets are available, 
and the terminal recognizes both 7-bit and 8-bit controls. This mode will run 
VT200 applications that use 8-bit control characters. The terminal operates 
most efficiently in this mode, but many systems and applications do not yet 
support 8-bit operation. 



10 VT300 FEATURES 



VT100 mode provides full compatibility with Digital's VT102 terminal. This 
mode restricts the terminal to a 7-bit environment. The keyboard is restricted 
to VT100 keys, and the only available character sets are ASCII, national re- 
placement characters, and DEC Special Graphic. You can use this mode with 
applications that require strict VT100 compatibility. 

VT52 mode provides full compatibility with Digital's VT52 terminal. This mode 
only uses Digital's private control functions, not standard ANSI functions. You 
use this mode with applications written for the VT52. 

Chapter 2 describes the format for 7-bit and 8-bit character codes. Chapter 4 
describes how the VT300 can emulate other VT series terminals. 



VT300 FEATURES 11 



2 



CHARACTER ENCODING 



Coding Standards, 13 

Characters and Character Sets, 15 

Code Table, 15 

7-Bit ASCII Code Table, 16 

8-Bit Code Table, 18 
VT300 Character Sets, 20 

DEC Supplemental Graphic Character Set, 21 

ISO Latin Alphabet Nr 1 Supplemental Graphic Character Set, 23 

National Replacement Character Sets (NRC Sets), 24 

DEC Special Graphic Character Set, 26 

DEC Technical Character Set, 27 

Down-Line Loadable (Soft) Character Set, 28 
Control Characters, 28 
Control Functions, 34 

Sequence Format, 35 

Escape Sequences, 35 

Control Sequences, 36 

Device Control Strings, 37 

Using Control Character in Sequences, 39 

7-Bit Code Extension Technique, 39 
Working with 7-Bit and 8-Bit Environments, 40 

Conventions for Codes Received by the Terminal, 40 

Conventions for Codes Sent by the Terminal, 41 
Display Controls Mode, 41 



12 



The VT300 uses a communication line to exchange information with a host sys- 
tem. The terminal and the host do not send data in the form you see on your 
screen. They must encode the information first. They also must be able to de- 
code the information received from each other. 

This chapter describes the character-encoding system that the VT300 uses for 
text. The terminal uses a different system for graphics. You must have a basic 
understanding of the character-encoding system described in this chapter before 
you use the control functions in the rest of this manual. 

The chapter also describes the VT300 character sets and the format for send- 
ing control functions to the terminal. You can select character sets for different 
countries or for special uses, such as technical characters. You use control func- 
tions to make the terminal perform special functions, such as editing or print- 
ing. 

CODING STANDARDS 

All terminals and computers encode information as binary digits, or bits. Older 
systems use 7 bits to encode each character. Newer systems such as the 
VT300 use 8 bits, which provide more codes. The newer systems can also use 
the 7-bit codes. 

The VT300 uses an 8-bit character-encoding system and a 7-bit code extension 
technique. The "7-Bit Code Extension Technique" section in this chapter ex- 
plains what 7-bit code extensions are. 

The American National Standards Institute (ANSI) and International 
Organization for Standardization (ISO) specify standards for character encoding 
in the information processing industry. The VT300 terminal is compatible with 
the following ANSI and ISO standards. 

Standard Description 

dpANS X3. 134.1 8-Bit ASCII structure and rules 

dpANS X3. 134.2 Code for information interchange of 7-bit 

and 8-bit ASCII supplemental multilingual 
graphic character set 

ANSI X3.4 — 1977 American Standard Code for Information 

Interchange (ASCII) 



CHARACTER ENCODING 13 



Standard 

ANSI X3.41 — 1974 



ANSI X3.32- 1973 



ANSI X3.64 — 1979 



ISO 646 — 1977 



ISO 2022 



ISO 6429 



ISO 8859-1 



ISBN 2-12-953907-0 



Description 

Code Extension Techniques for Use with 
the 7-Bit Coded Character Set of 
American National Code Information 
Interchange 

Graphic Representation of the 
Control Characters of American 
National Code for Information 
Interchange 

Additional Controls for Use with 
American National Standard for 
Information Interchange 

7-Bit Coded Character Set for 
Information Processing Interchange 

7-Bit and 8-Bit Coded Character 
Sets — Code Extension Techniques 

Additional Control Functions for 
Character Imaging Devices 

8-Bit single byte code graphic character 
sets-Part 1: Latin Alphabet Nr 1 

ISO international register of character 
sets used with escape sequences 



You can order ANSI and ISO standards from the following sources. 

ANSI Standards 

Sales Department 

American National Standards Institute 

1430 Broadway 

New York, NY 10018 

ISO Standards 

CCITT 

UN Book Store 

United Nations Building 

New York, NY 10017 



14 CHARACTER ENCODING 



CHARACTERS AND CHARACTER SETS 

In Digital's computing environment, a character is a symbol represented by an 
8-bit binary code. These symbols include letters, digits, and punctuation marks, 
as well as other symbols used to organize, control, or represent data. 

Here are a few examples of characters and their corresponding 8-bit codes. 



Character 


Code 


A 

} 
CSI 


01000001 
01111101 
10011011 



There are two types of computing environments, 7-bit and 8-bit. In a 7-bit envi- 
ronment, only the last 7 bits of the character code define the character. In an 
8-bit environment, all 8 bits define the character. 

The A character above is defined in a 7-bit or 8-bit environment, because the 
eighth bit of the code is 0. The 8-bit form of the CSI character is defined only 
in a 8-bit environment, because its eighth bit is 1. 

A coded character set is a group of characters that conform to certain rules 
and standards. These standards are set by organizations such ANSI and ISO. 
Each character in a character set is represented by a different combination of 8 
bits. 

CODE TABLE 

A code table is a convenient way to show all the characters in a character set 
with their codes. Most standard character sets put similar characters into 
groups, so they have similar codes. A code table lets you see groups of charac- 
ters and their relative codes clearly. 

There are two basic types of characters, graphic characters and control charac- 
ters. These two character types are defined by ANSI and ISO standards. The 
VT300 processes received characters based on these two character types. 

Graphic characters are characters you can display. Graphic characters include 
letters, numbers, punctuation marks, and any other characters you can display. 

Control characters are characters you do not usually display. They make the 
terminal or host system perform specific functions in data communications and 
text processing. 

CHARACTER ENCODING 15 



NOTE: You can display control characters on the screen, to help you debug 
your applications. To display control characters, use the Control 
Representation Mode feature in the Display Set-Up screen. See the "Display 
Controls" section at the end of this chapter. 

This section describes the format for 7-bit and 8-bit code tables. 

7-Bit ASCII Code Table 

Figure 2-1 is the 7-bit ASCII code table. The table has 128 character codes, 
arranged in 8 columns and 16 rows. 

Every character in a row uses the same binary code for its four least signifi- 
cant bits (Figure 2-2). This value appears at the left of each row. For example, 
every character in row uses the binary code 0000 for its four least significant 
bits. 

Every character in a column uses the same binary code for its three most sig- 
nificant bits. This value appears at the top of each column. For example, every 
character in column uses the binary code 000 for its three most significant 
bits 

The ASCII table also shows the octal, decimal, and hexadecimal code for each 
character. Different programmers may prefer using octal, decimal, or hexade- 
cimal codes for different purposes. 

This manual refers to characters by their position in the table. For example, 
the character H is at 4/8 (column 4, row 8). You can use the column/row num- 
ber to find a character and its codes in the table. For example 

ESC # 6 

1/11 2/3 3/6 



means 

The ESC character is at column 1, row 11. 
The ft character is at column 2, row 3. 
The 6 character is at column 3, row 6. 

The ASCII graphic characters are in positions 2/1 through 7/14 of the ASCII 
table. ASCII graphic characters include all American and English alphanumeric 
characters, plus punctuation marks and various text symbols. Examples are C, 
n, ", !, +, and $. (The British pound sign is not an ASCII graphic character.) 



16 CHARACTER ENCODING 





COLUMN 





1 


2 


3 


4 


5 


6 


7 


ROW 


hfi BITS 

67 
66 
bS 
b4 S3 b? bl 

























1 


























NUL 


o 






DLE 


zo 

10 


SP 


40 

32 
20 





60 
48 
30 


@ 


100 
64 


p 


120 
30 
50 


x 


140 
96 

60 


P 


112 
70 


1 


1 


SOH 


; 


DC1 

IXONI 


21 

17 


! 


41 
33 

21 


1 


49 
31 


A 


65 


Q 


121 
81 
51 


a 


141 

61 


q 


161 
113 
71 


2 


10 


STX 


2 
2 
2 


DC 2 


18 

12 


M 


42 

34 
22 


2 


62 
50 

32 


B 


102 

66 
42 


R 


B2 
52 


b 


9S 

62 


r 


114 

72 


3 


1 1 


ETX 


3 

3 

3 


DC 3 

(XOFFI 


23 
19 
13 


# 


43 

35 


3 


63 
51 
33 


C 


103 
67 

43 


S 


123 
B3 
53 


c 


143 
99 

63 


s 


lb J 
•15 
73 


4 


D 1 


EOT 


4 


DC4 


20 


$ 


36 
24 


4 


64 
52 

34 


D 


104 


T 


124 
B4 
54 


d 


144 
100 

64 


t 


164 

116 
74 


5 


10 1 


ENQ 


5 
5 
5 


NAK 


25 

21 
15 


% 


25 


5 


65 

53 
35 


E 


105 
69 
45 


U 


125 
85 

5b 


e 


101 
65 


u 


:G5 
75 


6 


110 


ACK 


■5 
S 

5 


SYN 


26 
22 


& 


40 
38 
26 


6 


66 
54 
36 


F 


106 
70 
46 


V 


126 
86 
56 


f 


146 
102 
66 


V 


166 
11B 
76 


7 


111 


BEL 




ETB 


23 
17 


' 


47 
39 
27 


7 


67 
55 

37 


G 


10/ 


w 


127 

e? 

57 


g 


147 
103 
67 


w 


167 

119 


8 


1 


BS 


10 


CAN 


30 
24 
Ifi 


( 


50 
40 
2B 


8 


70 

56 

3a 


H 


110 
72 


X 


130 

as 

58 


h 


150 
104 
68 


X 


170 
120 
78 


9 


10 1 


HT 


9 

S3 


EM 


25 
19 


) 


51 
41 

29 


9 


71 
57 
39 


1 


111 
73 
49 


Y 


131 
89 
59 


i 


151 
105 
69 


y 


171 
121 
79 


10 


10 10 


LF 


13 
10 


SUB 


32 
26 
1A 


# 


52 
42 
2A 




72 
58 
3A 


J 


112 


z 


132 

90 
Sit 


J 


152 
106 
6A 


z 


172 
122 
7A 


11 


lO'i 


VT 


13 

B 


ESC 


33 
27 

IB 


+ 


53 
43 

2B 


; 


73 
59 
3B 


K 


113 
75 
46 


[ 


133 
91 


k 


153 
107 
6B 


{ 


173 
123 
7B 


12 


110 


FF 


14 
12 
C 


FS 


31 
28 

1C 


, 


44 

2C 


< 


74 
60 
3C 


L 


76 


\ 


134 
92 
SC 


1 


154 
103 
60 


1 


174 
124 
7C 


13 


110 1 


CR 


15 
13 
D 


GS 


35 
29 
ID 


" 


55 
45 
2D 


- 


75 

61 
3D 


M 


115 
77 
4D 


] 


135 

93 
5D 


m 


155 

109 
6D 


> 


175 
125 
7D 


14 


1110 


SO 


(6 

F 


RS 


3G 
30 
IE 




56 
46 
2E 


> 


76 
62 
3E 


N 


116 
78 

4E 


A 


136 
94 

5E 


n 


156 
110 

6E 


"" 


126 

7E 


15 


1111 


SI 


17 
15 


US 


37 

31 
1F 


/ 


57 

2F 


? 


77 
63 
3F 





117 
4F 


- 


137 
95 

5F 





157 
6F 


DEL 


177 
127 
7F 



GL CODES 
"(ASCII GRAPHIC ) 



KEY 



CHARACTEf 



ESC 


33 
27 
IB 



OCTAL 
DECIMA 



Figure 2-1 7-Bit ASCII Code Table 



BIT 


BIT' 


BIT 


BIT 


BIT 


BIT 


BIT 


7 


6 


5 


4 


3 


2 


1 



4 ►♦« 



1 3 MOST 

SIGNIFICANT BITS 



4 LEAST 
SIGNIFICANT BITS 



(DECIMAL VALUE IS 
COLUMN IN 
CODE TABLE) 



(DECIMAL VALUE 
IS ROW IN 
CODE TAB LEI 



Figure 2-2 7-Bit Code 



CHARACTER ENCODING 17 



The ASCII control characters are in positions 0/0 through 1/15 (columns and 
1) of the ASCII table. The SP character (2/0) may act as a graphic space char- 
acter or a control character, depending on the context. DEL (7/15) is always a 
control character. 

ANSI and ISO standards define control character codes and their functions. 
These standards also define the mnemonic used to represent each control char- 
acter in a code table. Here are some examples of ASCII control characters with 
their mnemonics. 

ASCII Control Character Mnemonic (Appears in Code Table) 



Carriage return 


CR 


Form feed 


FF 


Cancel 


CAN 



8-Bit Code Table 

Figure 2-3 shows the format for an 8-bit code table. It has the same number of 
rows as the 7-bit table, but twice as many columns and character code posi- 
tions. 

Each character in a row of the 8-bit table uses the same binary code for its 
four least significant bits (Figure 2-4). Each character in a column uses the 
same binary code for its four most significant bits. 

The codes on the left half of the 8-bit table (columns through 7) work like the 
codes in the 7-bit table. You can use these codes in a 7-bit or 8-bit environ- 
ment. The eighth bit of these codes is 0. 

The codes on the right half of the table (columns 8 through 15) have an eighth 
bit of 1. You can only use these codes in an 8-bit environment. 

The 8-bit code table has two sets of control characters, CO (control zero) and 
CI (control one). The VT300 uses the ANSI definitions for the functions of CO 
and CI controls. The CO controls are in columns and 1. The CO controls are 
the same as the ASCII control characters in the 7-bit table. You can use CO 
controls in a 7-bit environment. 

The CI controls are in columns 8 and 9. They perform different functions than 
the CO controls. You can only use CI controls directly in an 8-bit environment. 
You can select CI codes indirectly in a 7-bit environment. The "7-Bit Code 
Extension Technique" section in this chapter explains how to select CI con- 
trols indirectly. Some CI code positions are blank, because their functions are 
not yet standardized. 



18 CHARACTER ENCODING 



COLUMN 
ROW V 


00 


01 


02 


03 


04 


05 


06 


07 


08 


09 


10 


11 


12 


13 


14 


15 


00 


MJL 


OLE 


SP 














DCS 














01 


SOH 


DC1 
















PU1 














02 


STX 


DC2 
















PU2 














03 


ETX 


DC3 
















STS 














04 


EOT 


OC4 














IND 


CCH 














OS 


ENQ 


NAK 














NEL 


MW 














06 


ACK 


SYN 














SSA 


SPA 














07 


BEL 


ETB 














ESA 


EPA 














08 


as 


CAN 














HTS 
















09 


HT 


EM 














HTJ 
















10 


LF 


SUB 














VTS 
















11 


VT 


ESC 














PLD 


CSI 














12 


FF 


FS 














PLU 


ST 














13 


CB 


GS 














Rl 


OSC 














14 


SO 


RS 














SS2 


PM 














15 


SI 


LIS 












DEL 


SS3 


APC 















*C1 CODE^I" 



-7-BIT CODE TABLE- 



MA-Q892-83 



Figure 2-3 8-Bit Code Table 



BIT 
8 


BIT 

7 


BIT 
6 


BIT 
5 


BIT 
4 


BIT 
3 


BIT 
2 


BIT 
1 


















I, 






r 1 - 






.1 


r" 














1 



4 MOST 
SIGNIFICANT BITS 



4 LEAST 
SIGNIFICANT BITS 



(DECIMAL VALUE IS 
COLUMN IN 
CODE TAB LEI 



(DECIMAL VALUE 
IS ROW IN 
CODE TABLE) 



Figure 2-4 8-Bit Code 



CHARACTER ENCODING 19 



NOTE: The VT300 does not recognize all CO and Cl codes. Tables 2-2 and 2-3 
list the codes the terminal recognizes. The terminal generally ignores all other 
control codes. 

The table also has two sets of graphic characters, GL (graphic left) and GR 
(graphic right). There are 94 GL codes in positions 2/1 through 7/14. You can 
use GL codes in 7-bit or 8-bit environments. 

There are 96 GR codes in positions 10/0 through 15/15. Some 8-bit character 
sets only use 94 of these GR codes. You can use GR codes only in an 8-bit 
environment. 

Together, the GL and GR sets make up the terminal's in-use table. The in-use 
table contains the graphic characters the terminal can currently use. Before the 
terminal can display and send characters from a character set, the set must be 
mapped into the in-use table. Chapter 5 describes the in-use table in detail. 

VT300 CHARACTER SETS 

The VT300 provides the following built-in character sets. 

ASCII 

DEC Supplemental Graphic 

ISO Latin Alphabet Nr 1 supplemental graphic 

12 national replacement character sets (NRCs) 

DEC Special Graphic 

DEC Technical 

You can also design and load a soft character set into the terminal. 
Down-line-loadable (soft) set 

All the VT300 character sets contain graphic and control characters. The func- 
tion of control characters never change, no matter what character set you use. 
The terminal always interprets CO and Cl control codes as defined by ANSI. 

The terminal stores the codes for graphic characters in GL and GR tables. 
Selecting a new character set changes the characters associated with the GL or 
GR codes. When you turn on or reset the terminal, you automatically select the 
following character sets. 

ASCII in GL 

DEC Supplemental (or ISO Latin-1 supplemental) graphic in GR 

Together, the ASCII and DEC Supplemental Graphic sets are known as the 
DEC Multinational character set. 



20 CHARACTER ENCODING 



DEC Supplemental Graphic Character Set 

This 8-bit character set has 94 graphic characters. The graphic characters in- 
clude letters with accents and diacritical marks, used in many European lan- 
guages. There are also special symbols, such as currency signs. 

When you first turn on your terminal, you automatically select the ASCII char- 
acter set and the DEC Supplemental Graphic set. The terminal maps the 
ASCII set into its GL table, and the DEC Supplemental Graphic set into its 
GR table. Together, these two character sets are known as the DEC 
Multinational character set (Figure 2-5). 





COLUMN 





1 


2 


3 


4 


5 


6 


7 


ROW 


bs BITS 

b? 
b6 

bb 
01 B3 52 b1 













1 










1 
] 


















1 








NUL 


□ 




DLE 


20 
16 

10 


SP 


40 

32 
20 





60 
48 
30 


@ 


100 

40 


p 


120 
80 
50 


x 


140 
96 

60 


p 


160 
112 

7C 


1 


i 


SOH 


; 


DC1 

(XON> 


21 
17 


i 


41 
33 
21 


1 


61 
49 

3! 


A 


101 
41 


Q 


121 
81 
51 


a 


97 

61 


q 


161 
113 


2 


10 


STX 


2 
2 
2 


DC2 


22 

12 


Tl 


42 
34 
22 


2 


62 
bO 

32 


B 


102 
66 
42 


R 


122 
82 

52 


b 


142 
96 

62 


r 


162 


3 


11 


ETX 


3 
3 
3 


DC 3 

(XOFF) 


23 
19 
13 


# 


43 
35 
23 


3 


63 

51 
33 


C 


103 
57 
43 


S 


B3 
53 


c 


143 
99 


s 


163 
115 
73 


4 


10 


EOT 


a 

4 


DC4 


24 
20 


S 


44 
36 
24 


4 


64 
52 
34 


D 


104 
68 

44 


T 


124 
84 
54 


d 


144 
100 
64 


t 


164 
116 


5 


10 1 


ENQ 


5 
5 
5 


NAK 


25 

21 

15 


/ 


45 
37 
25 


5 


65 
53 

35 


E 


105 
69 
45 


U 


35 
55 


e 


145 
101 
65 


u 


1S5 

117 
75 


6 


110 


ACK 


6 

6 


SYN 


26 
22 
16 


A 


46 
38 
26 


6. 


66 
54 
36 


F 


106 
46 


V 


126 
36 

56 


f 


146 
102 


V 


166 

76 


7 


1-11 


BEL 


7 
7 
7 


ETB 


71 
23 

17 


' 


47 
39 

27 


7 


67 
55 
37 


G 


107 
71 
47 


w 


127 
87 
57 


9 


147 
103 
67 


w 


'67 
119 
77 


8 


10 


BS 


10 

a 


CAN 


3(1 
24 

IE 


( 


SO 
40 
28 


8 


70 

S6 

3a 


H 


110 
72 
48 


X 


130 
58 


h 


150 
104 
6E 


X 


170 
120 
78 


9 


10 1 


HT 


9 
9 


EM 


31 
25 


) 


51 

41 
29 


9 


71 

57 
39 


1 


73 
49 


Y 


131 
89 
59 


i 


•51 
105 
69 


y 


•71 
121 
79 


10 


10 10 


LF 


12 
10 


SUB 


32 
26 


4t 


52 

42 
2A 




72 
58 
3A 


J 


112 
74 


2 


132 

90 
5A 


i 


152 
106 
6A 


z 


172 
122 


11 


10 11 


VT 


13 
B 


ESC 


33 
27 
IB 


♦ 


53 
43 
2B 


; 


73 
59 

3B 


K 


75 

4B 


[ 


133 
91 
5B 


k 


153 
107 

66 


< 


173 
123 

7B 


12 


110 


FF 


12 
C 


FS 


34 
28 


, 


54 
44 
?C 


< 


74 
80 
3C 


L 


114 
4C 


\ 


134 
92 
5C 


1 


154 
108 
6C 


1 


174 
124 
7C 


13 


110 1 


CR 


15 
13 
D 


GS 


35 
29 

ID 


• 


55 
45 
20 


■ 


75 
61 
3D 


M 


115 
77 
4D 


] 


13b 
93 
5D 


m 


155 

109 
6D 


} 


175 
125 
7D 


14 


1110 


SO 


E 


RS 


36 
30 
1E 




46 
2E 


> 


76 
62 
3E 


N 


116 
78 
4E 


A 


136 
94 
5E 


n 


156 

110 
6E 


**• 


176 
126 
7E 


15 




SI 


17 
IS 
F 


US 


37 
31 
1F 


/ 


57 
47 
2F 


? 


77 
63 
3F 





l 17 
79 

4F 


- 


137 
95 
5F 


o 


111 

6F 


DEL 


177 

127 
7F 



GL CODES 
(ASCII GRAPHIC ) 



KEY 



CHARACTER 



ESC 


33 
27 

IB 



MA-0S93-B3 



Figure 2-5 DEC Multinational Character Set 
(Left Half - CO and GL Codes) 



CHARACTER ENCODING 21 



NOTE: All control function descriptions in this manual assume that the termi- 
nal is using the DEC Multinational set. 

The DEC Supplemental Graphic set is the right half of Figure 2-5. The CI 
controls are in columns 8 and 9. The graphic characters are in columns 10 
through 15. 

You can select the DEC Supplemental Graphic set as the default by using con- 
trol functions or set-up. You can only use the DEC Supplemental Graphic set 
in VT300 mode. 



8 


9 


10 


11 


12 


13 


14 


15 


COLUMN 












1 









i 
i 




i 




i 




1 , 




" b 7 BITS 




a 













, 








c 


1 


1 





i 


T 


b5 


































54 03 b2 bl 


ROW 




200 




22D 


'///// 


240 


o 


260 




300 




.120 




340 




360 








128 
BO 


DCS 


144 
90 


W/a 


160 
AO 




1/6 
SO 


A 


192 
CO 




208 
DO 


a 


224 
60 




240 
FO 










201 




221 




241 




J61 


r 
A 


ini 




1?1 




141 




Tfil 








129 


PU1 


145 


I 


161 


± 


177 


193 


N 


209 




225 




241 


1 


1 




81 












B1 




CI 




L)l 




E1 












202 




222 




242 


2 


?F? 


A 
A 


302 





322 


A 


342 


* 


167 








13D 


PU2 


146 


c 


162 




176 


194 


210 


226 


742 


10 


? 




82 




92 




A3 




B2 




C2 


D2 




E2 




VI 








203 




223 




243 


3 


263 


«* 


303 




323 




141 




3fi1 








131 


STS 


147 


£ 


163 




179 


A 


195 





211 




227 




243 


11 


3 




83 




93 




A3 




B3 




C3 




D3 




b3 




F3 








204 




224 




244 




264 




304 


A 




324 




144 


A 








IND 


133 


CCH 


148 




164 




1HU 


A 


196 


212 




22B 


244 


10 


4 




84 




94 




A4 








C4 




D4 




E4 




F4 








205 




225 




241 




765 




305 




175 














NEL 


133 


MW 


149 


Y 


165 


M 


181 


A 


197 





213 


a 


?7fl 




245 


10 1 


5 




85 




95 




A5 




B5 




C5 


D5 




E5 




F5 








7Dfi 




226 




246 




?fifi 




306 




V>F, 




346 










SSA 


134 


SPA 


150 




166 


11 


182 


/E 


198 





214 


a 


230 




246 


110 


6 




36 




96 




A6 




B6 




C6 


D6 




t« 




(-6 








207 




227 




247 




267 




307 




127 




347 










ESA 


135 
87 


EPA 


151 
97 


§ 


A7 




183 

H7 


9 


199 

C7 


CE 


215 
D7 


9 


231 
E7 


OB 


247 
F7 


111 


7 




210 




?m 




250 




270 




110 








1511 




170 






HTS 


136 
88 




152 

98 


JO 


168 

AS 




184 


E 


200 
C8 





216 
DB 


e 


232 
E8 





248 

FB 


10 


8 




211 




231 




251 




771 


r 


311 








151 










HTJ 


137 




153 


(c) 


1R9 




185 


201 


u 


217 


e 


733 


U 


749 


10 1 


q 




aa 




99 




A9 




m 




C9 


UH 


E9 


F9 








212 




232 


a 







77? 


k 


312 




3.1? 


e 


15? 




372 






VTS 


138 




154 




170 




186 


202 


u 


218 


234 


u 


250 


10 10 


in 








9A 




AA 




BA 




CA 






LA 


FA 








213 




233 




253 




271 




313 


A 


in 




353 










PLD 


13a 


CSI 


155 


« 


171 


» 


187 


E 


203 


219 




235 




251 


10 11 


11 












AB 




B3 




CB 




DB 




LB 




t-B 








214 




234 




254 




774 












154 










PLU 


140 


SI 


156 




172 


% 


IBS 


j 


204 


u 


??n 


| 


236 




252 


1 1 □ 


1? 




8C 




9C 




AC 




BC 




CC 


DC 




tc 




FC 








215 




235 




255 








315 








155 










Rl 


141 


use 


167 




173 


% 


1B9 




205 


Y 


221 




237 


y 


253 


110 1 


13 




80 




90 




AD 




BD 






DD 




ED 




FD 








215 




236 




256 




276 


A 


31G 




^3fi 








17fi 






SS2 


142 


PM 


158 




174 




190 


206 




222 




73B 




254 


1110 


14 




8E 




9E 




AE 




BL 




ce 




DE 




EE 




FE 








217 




237 




757 




?77 




317 








1S7 


W4 








SS3 


143 


APC 


159 




175 




191 




207 


It 


223 


•.• 


219 


755 


1111 


15 




BF 




9F 




AF 




BK 




CF 




DF 




EF 


FF 







GR CODES 
(DEC SUPPLEMENTAL GRAPHIC ) 



Figure 2-5 DEC Multinational Character Set 
(Right Half — CI and GR Codes) 



22 CHARACTER ENCODING 



ISO Latin Alphabet Nr 1 Supplemental Character Set 

This 8-bit character set has 96 graphic characters. The graphic characters are 
similar to those in the DEC Supplemental Graphic set. The ISO Latin-1 sup- 
plemental set includes letters with accents and diacritical marks, used in many 
European languages. It also has other special symbols and letters, not included 
in the DEC Supplemental Graphic set. 

Figure 2-6 shows the ISO Latin-1 supplemental set. The CI controls are in 
columns 8 and 9. The graphic characters are in columns 10 through 15. 

You can select the ISO Latin-1 supplemental set as the default by using control 
functions (Chapter 5) or set-up. The combination of the ASCII character set in 
GL and the ISO Latin-1 supplemental set in GR is called the ISO Latin 
Alphabet Nr 1 character set. 

You can only use the ISO Latin-1 set in VT300 mode. 



8 


9 


10 


11 


12 


13 


14 


15 


COLUMN 
















1 










1 



i 




i 


" „, BITS 

b6 

b5 
b4 b3 b2 bl 




ROW 






30Q 
128 
30 


DCS 


220 
90 


NBSP 


240 
160 
AD 


° 


260 
176 

BO 


\ 
A 


300 
193 
CC 


■e 


320 
2D8 
DO 


a 


340 
224 

eo 


% 


360 
240 
FO 







201 
129 
81 


PU1 


221 

US 
91 


i 


241 
161 


± 


261 

177 
B1 


r 
A 


301 
193 

CI 


N 


321 
209 
D1 


a 


341 
225 

El 


n 


361 
241 

M 


1 


1 




202 

no 

82 


PU2 


222 

146 
92 


t 


242 

162 

A2 


2 


262 
17B 
B2 


A 

A 


3G2 
194 
C2 





372 
210 
D2 


k 


34.2 
22B 
E2 


o 


362 
242 

F2 


1 


2 




203 
131 
83 


STS 


223 
147 

y3 


£ 


243 

163 
A3 


3 


263 
179 


A 


303 

195 
C3 


r 



323 
211 
D3 


a" 


343 
227 
E3 


* 
o 


363 
243 

F3 


11 


3 


IND 


204 
132 
84 


CCH 


224 
148 
94 


» 


244 
164 
A4 


r 


264 
180 
B4 


V 


304 

196 
C4 


A 




324 
212 
04 


a" 


344 
223 
E4 


& 


364 
244 
F4 


10 


4 


NEL 


205 

133 

85 


MW 


225 
143 
95 


X 


245 
165 

A5 


M 


265 
1B1 
85 


A 


305 
197 
C5 





325 
213 

□6 


a 


345 
229 
E5 


o 


365 
245 
F5 


10 1 


5 


SSA 


206 

134 
86 


SPA 


226 
150 
96 


1 
1 


246 
166 

A6 


H 


182 
B6 


/E 


306 

19E 





326 
D6 


as 


346 
230 

E6 


o 


366 
246 

F6 


110 


6 


ESA 


207 
135 

87 


EPA 


227 
97 


§ 


247 
167 
A7 




267 
183 
B7 


? 


307 
199 
C? 


X 


327 

215 
D7 


5 


347 
231 

E7 


-r 


367 
247 

F7 


111 


7 


HTS 


210 
136 

88 




230 

152 
98 


II 


250 
168 
A8 


9 


270 
184 

B8 


E 


310 
200 

ce 





330 

216 
DB 


e 


350 
232 





370 
24B 
F8 


10 


8 


HTJ 


137 
85 




231 
153 
99 


© 


251 
169 
A9 


1 


271 
185 
89 


e 
E 


311 
201 
C9 


u 


331 
217 
D9 


w 

e 


351 
233 
ES 


\ 
U 


371 
249 
F9 


10 1 


9 


VTS 


212 
138 
8A 




232 

154 
9A 


a 


252 
170 

AA 





272 
186 
BA 


A 

E 


312 
202 
CA 


1 

u 


332 
218 
DA 


4 


362 
234 

EA 


w 

u 


372 

250 
FA 


10 10 


10 


PLD 


213 
139 
SB 


CSI 


233 
155 
98 


« 


253 
171 

AS 


» 


273 

137 


V 


313 

203 
C8 


A 

u 


333 
219 

DB 


V 


353 
235 

EB 


A 
U 


3/3 
251 
F8 


10 11 


11 


PLU 


140 


ST 


234 
15G 
9C 


—y 


254 
172 

AC 


% 


274 
1B8 
BC 


I 


314 
204 

CC 


if 


334 
220 

DC 


1 


354 
236 
EC 


*u 


374 
252 
FC 


110 


12 


Rl 


215 
141 
8D 


OSC 


235 

157 
9D 


— 


255 

AD 


% 


275 
189 
BD 


r 
I 


315 
205 
CO 


V 


335 
221 

DD 


r 


355 
237 
ED 


V 


375 

253 
FD 


, , o , 


13 


SS2 


216 
142 
3E 


PM 


J36 
15S 
9E 


® 


2&6 
174 
AE 


% 


276 
190 
BF 


f 


315 
206 
CE 


p 


336 
222 
DE 


A 
1 


356 
238 
FE 


P 


376 
254 
FE 


1110 


14 


SS3 


217 
143 
BF 


APC 


237 
159 
9F 


- 


257 
175 

AF 


c 


277 
191 


V 


317 
207 

CF 


JJ 


337 
223 
OF 


V 


357 
239 
EF 


V 


377 
255 

FF 


, , , , 


15 



-CI CODES ■ 



GR CODES 



ISO LATIN-1 SUPPLEMENTAL GRAPHIC 



MA-OS94D-83 



Figure 2-6 ISO Latin Nr 1 Supplemental Character Set 



CHARACTER ENCODING 23 



National Replacement Character Sets (NRC Sets) 

The NRC sets provide character sets for many European languages. There are 
12 NRC sets. Each is a 7-bit character set with 94 graphic characters. The 
NRC sets are similar to the ASCII set, except for a few characters. 

NOTE: Digital recommends that you operate the terminal in an 8-bit environ- 
ment. The NRC sets are only provided for compatibility with 7-bit environ- 
ments. 

Table 2-1 lists the characters in each NRC set that are different from the 
ASCII set. To use an NRC set, you must select national replacement character 
set mode. You can select this mode by using a control function or set-up. You 
can only use one NRC set at a time. The NRC set used depends on the key- 
board selected in set-up, as follows. 



Keyboard 

United Kingdom 

Danish 

Dutch 

Finnish 

Flemish 

French/Belgian 

French Canadian 

German 

Italian 

Norwegian 

Portuguese 

Spanish 

Swedish 

Swiss (French) 

Swiss (German) 



NRC Set 

United Kingdom 

Norwegian/Danish 

Dutch 

Finnish 

French 

French 

French Canadian 

German 

Italian 

Norwegian/Danish 

Portuguese 

Spanish 

Swedish 

Swiss 

Swiss 



24 CHARACTER ENCODING 



Table 2-1 National Replacement Character Sets 



Ch«racter Set 


2/3 


4/0 


5/11 


5/12 


5/13 


5/14 


ASCII 


# 


@ 


I 




\ 




] 




" 




United Kingdom 


£ 


® 


I 




\ 




I 




,«;' 




Dutch 


% 


y 




\>7 




Finnish 


# 


@ 


A 




6 




A 









French 


£ 


a 


o 




c 




§ 








French Canadian 


# . 


a 


a 




c 




e 




I 




German 


# 


■§ 


A 




6 









* 




Italian 


£ 


§ 


: .©■■ 




c 




e 








Norwegian/Danish 


# . 


@ 


/E 









A 




" 




Portuguese 


# 


@ 


A 




C 









... . 




Spanish 


£ 


§ 


' 




ft 




6 




'■ 




Swedish 


.#■■ 


E 


A 




6 




A 









Swiss 


u 


a 


e 




c 




e 




J 




Character Set 


5/15 


6/0 




7/11 




7/12 




7/13 




7/14 


ASCII 








i 




I 




J 




s^iWSS 


United Kingdom 








r 








J 




■ '■ • 


Dutch 












f 




'/4 




.'■^ ■ ■ .' 


Finnish 








a 




6 




e 




U 


French 








4 




u 




e .. 






French Canadian 








1 




Li 




8 ' 







German 








a 




6 




11 




R i ; 


Italian 








a 




6 




e 




I 


Norwegian/Danish 








ae 









a 




§|lfll|l 


Portuguese 


sss 






n 




c 




6 




** 


Spanish 








■ 




o 




n 




c 


Swedish 








a 




6 




a 




ii 


Swiss 


e 


6 




a 




6 




U 




; ; '§ : ':'- ; : : 



CHARACTER ENCODING 25 



DEC Special Graphic Character Set 

This 7-bit character set has 94 graphic characters. Most of the graphic charac- 
ters are also in the ASCII character set. The other graphic characters include 
special symbols and line-drawing characters. 

Figure 2-7 shows the DEC Special Graphic set. The CO controls are in columns 
and 1. The graphic characters are in columns 2 through 7. 

Another name for this character set is the VT100 line-drawing character set. 
The line-drawing characters let you create a limited range of pictures when you 
use the VT300 as a text terminal. 

You can use the DEC Special Graphic set to replace the ASCII set in GL or 
the DEC Supplemental Graphic set in GR. Chapter 5 describes how to select 
character sets. 





COLUMN 





1 


2 


3 


4 


5 


6 


7 




BITS 

B7 
B6 
B5 
B4 B3 B2 91 




















o 












ROW 





C 


NUL 







DLE 


20 


SP 


40 
32 

20 


O 


so 

43 
30 


@ 


100 
64 
40 


P 


120 
80 
50 


• 


140 
96 


SCAM 3 


160 
112 
70 


1 


Q D I 


SOH 


; 


DC1 

IXON) 


17 


I 


33 
21 


1 


51 
49 

31 


A 


101 
65 


Q 


121 

81 

51 


i 


97 

61 


SCAN 5 


161 
113 
71 


2 


10 


STX 


2 

2 


DC2 


22 
18 
12 


ii 


47 

34 
22 


2 


62 
50 

32 


B 


'02 
42 


R 


122 
B2 
52 


\ 


142 
98 
62 


SCAN 7 


'52 
72 


3 


oo't 


ETX 


3 
3 
3 


DC3 

IXOFF) 


23 

13 


# 


43 


3 


G3 

51 
33 


C 


103 
67 

43 


S 


! 23 
83 

53 


s 


143 
99 
63 


SCAN 9 


■63 

115 
73 


4 


10 


EOT 


: 


DC4 


20 
14 


$ 


36 
24 


4 


64 
52 

34 


D 


104 
68 


T 


121 
84 

54 


\ 


100 

£4 


r 


161 


5 


O'Ol 


ENQ 


r> 

5 
5 


NAK 


25 
15 


% 


15 
37 

25 


5 


65 
53 
35 


E 


105 
69 
4b 


U 


125 

S5 

L bb 


F 


101 
65 


\ 


1'7 
75 


6 


110 


ACK 


6 

6 


SYN 


26 
22 

IB 


& 


45 

33 
26 


6 


66 
54 
36 


F 


'06 
70 

46 


V 


126 
86 

56 





146 

102 
66 


L 


1 66 
1 18 
76 


7 


1 1 1 


BEL 




ETB 


27 

23 

17 


' 


47 
33 

27 


7 


67 
55 

37 


G 


107 
71 
47 


w 


127 
87 
57 


t 


147 
1C3 

67 


T 


167 
119 
77 


8 


10 


BS 


10 


CAN 


24 
13 


( 


40 

78 


8 


m 

56 
3E 


H 


110 
72 

48 


X 


130 

se 

58 


N 

L 


150 
194 


1 


170 
120 
78 


9 


10 0' 


HT 


11 


EM 


25 

19 


) 


51 


9 


71 
57 
39 


I 


73 

49 


Y 


131 

39 
59 


1 


151 
10E 


£ 


121 
79 


10 


10 10 


LF 


12 

10 
A 


SUB 


J? 
2c 


* 


S2 
42 
2A 




72 
58 
3A 


J 


]•■? 


z 


! 32 
5A 


i 


15? 
106 

6A 


£ 


172 
122 
7A 


11 


10 11 


VT 


13 


ESC 


33 
27 

IB 


+ 


53 
43 
2B 


; 


73 
59 


K 


■•3 
75 

4fi 


C 


133 

91 
5B 


l 


15.3 

107 
66 


I 


173 
123 
IB 


12 


; 1 o o 


FF 


12 


FS 


?A 
28 


, 


54 
2C 


< 


74 
60 
3C 


L 


114 

76 


\ 


92 

5C 


r 


154 
108 
6C 


* 


174 
124 
7C 


13 


110 1 


CR 


■5 
13 


GS 


35 

29 
ID 


" 


5E> 
45 
2D 


= 


75 

SI 
3D 


M 


115 
77 
4D 


3 


'35 

93 
5D 


L 


'55 
109 
60 


£ 


175 
125 

70 


14 


1110 


SO 


16 

E 


RS 


36 
30 
IE 




55 
46 

2E 


> 


76 
62 
3E 


N 


P6 
/8 

4E 


A 


136 
94 
5F 


f 


156 

110 
6E 




175 
126 

7F 


15 




SI 


17 


US 


37 
3 ! 


/ 


57 
2F 


7 


11 
53 

3F 


O 


117 

79 
4F 


(BLANKI 


'37 
95 

5F 


SCAN 1 


'57 
i=F 


DEL 


1 II 
17 7 
7F 



GL CODES 
(DEC SPECIAL GRAPHIC ) 



KEY 



ESC 


33 
27 

IB 



MA-0893C-83 



Figure 2-7 DEC Special Graphic Character Set 



26 CHARACTER ENCODING 



DEC Technical Character Set 

This 7-bit character set has 94 graphic characters. The DEC Technical set has 
characters and symbols often used in technical applications, such as schematic 
and logic diagrams. 

Figure 2-8 shows the DEC Technical set. The CO controls are in columns and 
1. The graphic characters and symbols are in columns 2 through 7. You can 
use the characters in positions 2/1 through 3/7 to form large composite 
characters. 

You can use the DEC Technical set to replace the ASCII set in GL or the 
DEC Supplemental Graphic set in GR. You can only use the DEC Technical 
set in VT300 mode. 



BB 
B7 
BB 

65 
















' , 





" . 


i 




• , 


1 


BITS 






GL 


GR 




GL 


GR 




GL 


GR 




GL 


GR 




GL 


GR 




GL 


UK 


B4 B3 B2 B1 


CO 


LUMN 


2 


10 




3 


11 




4 


12 




5 


13 




6 


14 




7 


15 





OW 










h 


48 
30 


260 
176 
BO 


• 
• • 


100 
64 
40 


300 
192 
CO 


n 


12C 
80 

50 


320 
208 
DO 


- 1 


140 
96 

60 


340 
224 

Ed 


IT 


160 

117 
70 


360 
240 

FO 


Q ' 


1 


4 


33 
21 


241 
161 

A1 


V 


61 
49 
31 


261 
177 
Bl 


oc 


101 

65 


301 
193 


* 


121 
5' 

51 


321 
209 
D1 


a 


97 


341 
226 

El 


* 


161 
113 


361 

241 
Fl 


10 


2 


r 


42 
34 
?? 


242 
162 


L 


62 

50 
32 


262 
178 
82 


oo 


102 
66 

42 


302 
194 
C2 




82 

52 


322 
210 

D2 


3 


142 
98 

62 


342 
226 
E2 


P 


162 
72 


362 
242 
F2 


11 


3 


- 


43 
35 
23 


243 
163 


\ 


63 
51 
33 


263 
179 
B3 


f 


103 
67 
43 


303 
195 
C3 


z 


123 
83 
03 


323 
211 

03 


X 


143 
99 
63 


343 
227 
E3 


a 


163 
115 
73 


363 
243 
F3 


1 


4 


r 


36 

24 


164 
A4 


/ 


6J 
52 

34 


264 
1B0 
84 


A 


104 
6B 


304 
196 
C4 




124 

84 
54 


324 
212 
D4 


S 


100 


344 
228 
E4 


T 


164 
116 

;4 


364 
244 

F4 


10 1 


5 


j 


45 

37 


245 

165 
AS 


- 1 


65 
53 
35 


265 
05 


V 


105 
69 

45 


305 
197 
C5 




125 
55 


37b 
213 

D5 


e 


145 
101 
65 


345 
279 
E5 


c 


165 
75 


365 
245 
F5 


110 


6 


i 


46 
33 


246 
166 
A6 


_l 


66 
54 

3E 


266 
132 
B6 


$ 


106 

70 
46 


198 
C6 


V 


126 
86 
56 


214 
D6 


* 


146 
102 
65 


230 

ES 


/ 


166 
118 

76 


246 
F6 


„ , , , 


7 


r 


30 
2? 


247 
167 
A? 


> 


67 

55 
37 


267 
183 
B7 


r 


107 
71 
47 


307 
199 

C7 


A 


1?? 
87 

57 


215 

D7 


Y 


147 

103 
67 


347 
231 

E7 


u> 


167 
119 

77 


367 
24 7 
F7 


10 


8 


L 


50 
40 
28 


250 
168 
A8 


C 


m 

56 
38 


270 
1B4 
68 


/*»^ 


110 
72 
48 


310 
200 
C8 


£ 


Be 

58 


33U 
216 
D8 


n 


150 
104 
68 


350 
232 

E9 


S 


170 

120 

7B 


370 
248 
F8 


10 1 


9 


i 


51 

29 


351 
169 

A9 




57 
39 


271 
185 
B9 


*N* 


73 
49 


311 
201 

C9 


T 


131 
H9 
59 


331 
217 
09 


i 


15' 
105 
69 


351 
233 
E9 


V) 


171 
171 
79 


371 

249 
F9 


1 1 


10 


j 


0? 
4? 
2A 


252 
170 
AA 




72 

58 
3A 


272 
186 
BA 





112 


312 
202 
CA 


c 


132 
90 
5A 


218 

DA 


e 


106 

6A 


234 
EA 


t 


122 
7A 


250 
FA 


10 11 


11 


r 


43 
2E 


253 
171 
AB 




73 
59 
3B 


273 
187 
SB 


X 


113 
75 
4B 


313 
203 
CB 


3 


133 

91 


333 
219 
DB 


K 


107 
6B 


235 
EB 


«- 


123 
7B 


251 
FB 


1 1 


12 


i 


54 
7C 


254 
172 
AC 


< 


74 
60 
3C 


774 
136 
BC 


A 


114 
76 
4C 


314 
204 
CC 


n 


134 
82 
5C 


334 
220 
DC 


X 


154 
108 
6C 


354 
236 

EC 


t 


124 
7C 


374 
252 
FC 


110 1 


13 


^ 


55 

46 
2D 


255 
173 

AD 


— 


'5 
61 
3D 


275 
139 
BD 


O 


115 

77 
4D 


315 
205 
CD 


u 


135 
93 

5D 


221 
DD 




155 

109 
60 


237 
ED 


■* 


125 
70 


253 
FD 


1110 


14 


) 


56 
46 
2E 


256 
174 

AE 


> 


76 

3E 


276 
190 

BE 


=> 


116 
78 
4E 


316 
206 
CE 


A 


136 
94 
SE 


336 
222 
DE 


V 


15S 
110 
6E 


356 
23B 
EE 


I 


176 

126 
7E 


376 
254 
FE 


, , , , 


15 


\ 


57 
47 

2F 


257 
175 
AF 


/ 


77 
63 

3F 


277 
191 
EF 




11 

7S 
4F 


317 
207 
CF 


V 


95 
5F 


223 
DF 


a 


111 
6F 


239 

EF 









LEGEND 




CODES 
/ \ 


CHARACTER , 


-A 


101 
65 


301 
193 






41 


CI 



♦NOTE: 

WHEN SET IS MAPPED INTOGR. 
BITB81S1 [V2 0NL.Y). 



Figure 2-8 DEC Technical Character Set 



CHARACTER ENCODING 27 



Down-Line-Loadable (Soft) Character Set 

The VT300 lets you down-line-load a character set from the host system. The 
character set can have up to 96 graphic characters. You can design your own 
character set, then load the set into the terminal. You can use the set in GL or 
GR. Chapter 5 describes how to load and use a soft character set. 

You can only use this character set in VT300 mode. 

CONTROL CHARACTERS 

The purpose of a control character is to control an action such as line spacing, 
paging, or data flow. The terminal does not display control characters unless 
you select display controls mode (described later in this chapter). There are two 
groups of control characters. 

CO 7-bit control characters, in columns and 1 of the 8-bit code table 
CI 8-bit control characters, in columns 8 and 9 of the 8-bit code table 

Table 2-2 lists the CO control characters the VT300 recognizes. Table 2-3 lists 
the CI control characters the VT300 recognizes. You can also code Cl control 
characters as 7-bit escape sequences. Table 2-4 lists the equivalent 7-bit se- 
quences for 8-bit control characters. All three tables give column/row locations 
to help you find the characters in the character sets. 

Table 2-2 CO (7-Bit) €»iuj*of Characters Recognised 



Name 
Null 

Enquiry 

Bell 

Backspace 



Mnemonic 
Column/Row 

NHL 
0/0 

ENQ 

0/5 

BEL 

0/7 

BS 

0/8 



Function ' 

Ignored. 

Sends answerback message. 

Sounds the bell tone if the bell is 

enabled in set-up. '.■' ■ : ■;.:■■: : ,"■•;:' ■ 

Moves the cursor one character position 

to the left. If the cursor is at the left margin, no 

action occurs. 



28 CHARACTER ENCODING 



Tabic 2-2 CO (7-Bit) Coni rol Chai ac toi * Recogni ted (Cont) 



Name 

Horizontal 
tab 



Mnemonic 
Column/Row 

HT 

0/9 



Line feed 


LF 

0/10 


Vertical 
tab 


VT : 

0/11 


Form feed 


FF 

0/12 


Carriage 
return 


CR 

0/13 


Shift out 
(Locking 
shift!) 


SO (LSI) 
0/14 



Function 

Interactive mode 

Moves the cursor to the next tab stop. If there 

are no more tab stops, the cursor moves to the 

right margin. HT does not cause text to auto 

wrap. 

Local editing *>>.ode 

Depends on the setting of erasure mode (ERM). 

ERM set Moves the cursor to the next tab 

stop or field boundary. 

ERM reset Moves the cursor to the next unpro- 
tected field boundary. 

If there are no tab stops or character fields in the 
scrolling region, the page scrolls to the next tab 
stop or field. 

Causes a line feed or a new line 

operation dej ending m the setti ig - I line feed/ 

new line mode. 

Treated as LF. 

Treated as LF. 

Moves the cursor to the left margin 
on the current line. 

Maps the Gl character set into GL. You 
designate Gl by using a select character 
set (SCS) sequence (Chapter 5). 



CHARACTER ENCODING 29 



Table 2-2 CO (7-Bit) Control Characters Recognized (Cont) 



\ ■■.;. 



Mnemonic 
Column/Row Function 



Shift in 
(Locking 
shift 01 


SI 

0/15 


Device . 

control 1 
(XON) 


DC1 

1/1 


Device 
control 3 
(XOFF) 


DC3 

1/3 


Device 

control 4 


DC4 

1/4 


Cancel 


CAN 
1/8 


Subst.il.uH' 


SUB 

1/10 


Escape 


ESC 

1/11 



Delete 



DEL 

7/15 



Maps the GO character set into GL. You 
designate GO by using a select character 
set (SCS) sequence (Chapter 5). 

Also known as XON. If XON/XOFF flow 
control is enabled in set-up. DCl clears 
DC3 (XOFF). This action causes the VT300 
to continue sending characters. 

Also known as XOFF. If XON/XOFF flow 
control is enabled in set-up, DCS causes 
the VT300 to stop sending characters. The termi- 
nal cannot resume sending characters until it re- 
ceives a DCl control character. 

Introduces an SSI) session management 
command. The VT300 and host use this control 
to separate SSU commands from ANSI text and 
control functions. See Chapter 14. 

Immediately cancels an escape sequence, 
control sequence, or device control string in pro- 
gress. The VT300 does not display any error 
characters. ■ ■ ■ 

Immediately cancels an escape sequence, 
control sequence, or device control string in pro- 
gress. The VT300 displays a reverse question 

mark c for an error character. 

Introduces an escape sequence. 
ESC also cancels any escape sequence, control se- 
quence, or device control string in progress. 

Ignored when received, unless a 
96-character set is mapped into GL. DEL is not 
used as a fill character. Digital does not recom- 
mend using DEL as a fill character. Use NUL 

Instead. ■■■ 



30 CHARACTER ENCODING 



Table 2-3 CI (8-Bit) Control Characters Recognized 



Name 
Index 

Next line 



Start 

selected 

area 

End 

selected 

area 

Horizontal 

tab set 

Reverse 
index 



Single 
shift 2 



Single 
shift 3 



Device 
control 
string 

Set 

transmit 

state 



Mnemonic 

Cchinm/Rim- 

IND 

8/4 

NEL 
8/5 

SSA 

8/6 

ESA 

8/7 

HTS 

8/8 

HI 

8/13 

SS2 

8/14 



SS3 
8/15 



DCS 

9/0 

STS 

9/3 



Function 

Moves the cursor down one line in the 
same column. If the cursor is at the bottom mar- 
gin, the pago scrolls up. ■ 

Moves the cursor to the first position 

on the next line. If the cursor is at the bottom 

margin, the page scrolls up. ;.'. : - ':;.-->-" 

Defines the cursor position as the start 
of a block of data eligible to be sent 
;.;fe: : the host (Chapter 9). : :. v 

Defines the cursor position as the end of 
a block of data eligible to be sent to 
the host (Chapter 9). 

Sets a horizontal tab stop at the column 
where the cursor is. . 

Moves the cursor up one line in the same 
column. If the cursor hi at the top margin, the 
page scrolls down. 

Temporarily maps the G2 character set 
into GL. for the next graphic character. You des- 
ignate the G2 set. by using a select character set 
' (SCS) sequence (Chapter 5). ' ' 

Temporarily maps the G3 character set 
into GL. for the next graphic character. You des- 
ignate the G3 set by using a select character set 
(SCS) sequence (Chapter 5). : : : . :; ; .'. 

Introduces a device control string. 



The VT300 sends STS to the host to 
request a block transmission 
(Chapter' 9). 



CHARACTER ENCODING 31 



Table 2-3 CI (8-Bit) Control Characters Recognized (Cont) 



Name 



Mnemonic 
Column/Row Function 



Start 

protected 

area 


SPA 

9/6 


End 

pmtoctod 

area 


E P \ 

9/7 


Control 

sequence 

introducer 


CSI 

9/11 


String 
terminator 


ST 
9/12 


Operating 

system 

command 


osc 

9/13 


Privacy 
message 


PM 

9-14 


Application 

program 

command 


APC 

9/15 



Defines the cursor position as the start 
of a character string that you cannot 
edit from the keyboard. 

Defines the cursor position as the end of 
« character string that you cannot edit 

from the keyboard. : ;: '^ : ':. :.V '{'■: :;/V;V:'.Y ;: .' 

Introduces a control sequence. 



Ends a device control string. You use ST 
in combination with DCS. 

Introduces an operating system command.* 



Introduces a privacy message string.* 

Introduces an application program 

command.* 



* The VT300 ignores all following characters, until it receives a SUB. ST. or 
any other CI control character. V:'.-:. ;; .. ; -.:: ; .;v- .-'/: : . /■■■"' .-';'; ■ ■ 

Table 2-4 8-Bit Control Characters and Their 7-Bit Equivalents 



Name 
Index 

Next line 



8-Bit 


7-Bit 


Character 


Sequence 


IND 


ESC D 


8/4 


1/11 4/4 


NEL 


ESC E 


8/5 


1/11 4/5 



32 CHARACTER ENCODING 



Table 2-4 8-Bit Control Characters and Their 7-Bit Equivalents (Cont) 



Name 


8-Bit 
Character 


7-Bit 
Sequence 


Start selected area 


SSA 

8/6 


ESC F 

1/11 4/6 


End selected area 


ESA 
8/7 


ESC G 

1/11 4/7 


Horizontal tab set 


HTS 

8/8 


ESC H 

1/11 4/8 


Reverse index 


RI 

8/13 


ESC M 

1/11 4/13 


Single shift 2 


SS2 

8/14 


ESC N 

1/11 4/14 


Single shift 3 


SS3 

8/15 


ESC O 

1/11 4/15 


Device control string 


DCS 

9/0 


ESC P 

1/11 5/0 


Set transmit state 


STS 

9/3 


ESC S 

1/11 5/3 


Start protected area 


SPA 

9/6 


ESC V 

1/11 5/6 


End protected area 


EPA 

9/7 


ESC W 

1/11 5/7 


Control sequence 
introducer 


CSI 

9/11 


ESC { 

1/11 5/11 


String terminator 


ST 

1/11 


ESC \ 

1/11 5/12 


Operating system 
command 


OSC 

9/13 


ESC 1 

1/11 5/13 


Privacy message 


PM 

9/14 


esc : 

1/11 5/14 


Application program 


APC 

9/15 


ESC 

1/11 5/15 



CHARACTER ENCODING 33 



CONTROL FUNCTIONS 

You use control functions to make the terminal perform special actions in your 
applications. These functions range from the simple — editing data — to the 
complex — reporting on the terminal's operating state. The rest of this manual 
covers the many uses for control functions. Here are some examples. 

Move the cursor. 

Delete a line of text. 

Select bold or underlined text. 

Change character sets. 

Make the terminal emulate a VT52 or VT100 terminal. 

You can use all control functions in text mode. There are single-character and 
multiple-character control functions. 

The single-character functions are the CO and CI control characters. You can 
use CO characters in a 7-bit or 8-bit environment. Cl characters provide a few 
more functions than CO characters, but you can only use Cl characters directly 
in an 8-bit environment. 

Multiple-character functions provide many more functions than the CO and Cl 
characters. Multiple-character functions can use control characters and graphic 
characters. There are three basic types of multiple-character functions. 

escape sequences 
control sequences 
device control strings 

Many sequences are based on ANSI and ISO standards, and are used through- 
out the industry. Others are private sequences created by manufacturers like 
Digital for specific families of products. ANSI sequences and private sequences 
follow ANSI and ISO standards for control functions. 

In this manual, private control functions created by Digital have the prefix 
DEC in their mnemonic name. For example, column mode has the mnemonic 
DECCOLM. All other control functions are standardized. 

The following sections describe the format for escape sequences, control se- 
quences, and device control strings. 

PROGRAMMING TIP: When you use control functions, remember that the bi- 
nary codes define a function — not the graphic characters. This manual uses 
graphic characters from the DEC Multinational character set to show control 
functions. If you use another character set, the graphic characters for control 
functions may change, but the code is always the same. 



34 CHARACTER ENCODING 



Sequence Format 

This manual shows escape and control sequences in their 8-bit format. You can 
also use equivalent 7-bit sequences (Table 2-4). 

The 8-bit format uses the CO and CI control characters and ASCII characters 
from the DEC Multinational character set. The sequences also show each cha- 
racter's column/row position in the character set table, below the character. The 
column/row code eliminates confusion over similar looking characters such as 
(3/0) and O (4/15). 

NOTE: Spaces appear between characters in a sequence for clarity. These 
spaces are not part of the sequence. If a space is part of the sequence, the SP 
(2/0) character appears. 

Escape Sequences 

An escape sequence uses two or more bytes to define a specific control func- 
tion. Escape sequences do not include variable parameters, but may include in- 
termediate characters. Here is the format for an escape sequence. 

ESC I F 

1/11 2/0 to 2/15 3/0 to 7/14 

Escape Intermediate Final 

characters character 

(zero or more (one character) 
characters) 

ESC introduces escape sequences. After receiving the ESC control character, 
the terminal interprets the next received characters as part of the sequence. 

I represents zero or more intermediate characters that can follow the ESC 
character. Intermediate characters come from the 2/0 through 2/15 range of the 
code table. 

Fj6 the final character. This character indicates the end of the sequence. The 
final character comes from the 3/0 through 7/14 range of the code table. The 
intermediate and final characters together define a single control function. 

For example, the following escape sequence changes the current line of text to 
double-width, single-height characters. 

ESC # 6 

1/11 2/3 3/6 



CHARACTER ENCODING 35 



Control Sequences 

A control sequence uses two or more bytes to define a specific control function. 
Control sequences usually include variable parameters. Here is the format for a 
control sequence. 

CSI P...P I...I F 

9/11 3/0 to 3/15 2/0 to 2/15 4/0 to 7/14 

Control Parameter Intermediate Final 

sequence (zero or more (zero or more (one character) 

introducer characters) characters) 

CSI is the control sequence introducer. You can also use the equivalent 7-bit 
sequence, ESC (1/11) [ (5/11), as a substitute for CSI. After receiving CSI, the 
terminal interprets the next received characters as part of the sequence. 

P...P are parameter characters received after CSI. These characters are in the 
3/0 to 3/15 range in the code table. Parameter characters modify the action or 
interpretation of the sequence. You can use up to 16 parameters per sequence. 
You must use the ; (3/11) character to separate parameters. 

All parameters are unsigned, positive decimal integers, with the most signifi- 
cant digit sent first. Any parameter greater than 9999 (decimal) is set to 9999 
(decimal). If you do not specify a value, a value is assumed. A value or 
omitted parameter indicates a default value for the sequence. For most se- 
quences, the default value is 1. 

NOTE: All parameters must be positive decimal integers. Do not use a decimal 
point in a parameter — the terminal will ignore the command. 

If the first character in a parameter string is the ? (3/15) character, it indicates 
that DEC private parameters follow. The terminal interprets private param- 
eters according to ANSI X3.64 and ISO 6429. 

The VT300 processes two types to parameters, numeric and selective. 

Numeric Parameters - A numeric parameter indicates a number value such as 
a margin location. In this manual, numeric parameters appear as actual values 
or as Pn, Pnl, Pn2, and so on. 

The following is an example of a control sequence with numeric parameters. 



36 CHARACTER ENCODING 



CSI 


5 


♦ 


2 


r 


9/11 


3/5 


3/11 


3/2 3/0 


7/2 


Control 


First 


Delimiter 


Second 


Final 


sequence 


numeric 




numeric 


character 


introducer 


parameter 




parameter 





This sequence sets the top and bottom margins of the current page. The top 
margin is at line 5, the bottom is at line 20. The ; (3/11) separates the two 
parameters. 

Selective Parameters - A selective parameter selects an action associated with 
the specific parameter. In this manual, selective parameters usually appear as 
Ps, Psl, Ps2 and so on. 

The following is an example of a control sequence using selective parameters. 



CSI 

9/11 

Control 

sequence 

introducer 



1 
3/1 

First 

selective 

parameter 



3/11 
Delimiter 



4 
3/4 



m 

6/13 



Second Final 

selective character 
parameter 



This control sequence turns on the bold and underline attribute at the the cur- 
sor position. The parameters are 1 (indicating the bold attribute)and 4 (indicat- 
ing the underline attribute). The ; (3/11) delimiter separates the two 
parameters. 

I...I are zero or more intermediate characters received after CSI. These charac- 
ters are in the 2/0 to 2/15 range. 

F is the final character from the 4/0 to 7/14 range. The final character indi- 
cates the end of the sequence. The intermediate and final characters together 
define a control function. If there are no intermediate characters, the final char- 
acter defines the function. 

Device Control Strings 

Device control strings (DCS), like control sequences, use two or more bytes to 
define specific control functions. However, a DCS also includes a data string. 
Here is the format for a device control string. 



CHARACTER ENCODING 37 



DCS 


P...P 


I...I 


F 


Data string 


ST 


9/0 


3/0 


2/0 


4/0 


%$:%t%%t%i%:%i$i$:%%: 


9/12 




to 


to 


to 








3/15 


2/15 


7/15 






Device 


Zero or 


Zero or 


Final 


String 


String 


control 


more 


more 






terminator 


string 


para- 


inter- 








introducer 


meters 


mediates 









DCS is the device control string introducer. DCS is the CI control character at 
position 9/0. You can also use the equivalent 7-bit sequence, ESC (1/11) P (5/0). 
After receiving DCS, the terminal processes the next received characters as 
part of the string function. 

P..P are parameter characters received after DCS. Parameter characters are in 
the 3/0 to 3/15 range. They modify the action or interpretation of the device 
control string. You can use up to 16 parameters per string. Each parameter is 
separated with a ; (3/11) character. These characters follow the same rules as in 
a control sequence. See the "Control Sequences" section in this chapter. 

I...I are zero or more intermediate characters received after CSI. These charac- 
ters are in the 2/0 to 2/15 range. 

F is the final character in the 4/0 to 7/14 range. The final character indicates 
the end of the string. The intermediate and final characters define the string. 
If there are no intermediates, the final character defines the string. 

Data string follows the final character and usually includes several definition 
strings. Each definition string can be several characters in length. Individual 
strings are separated by the ; (3/11) delimiter. 

ST is the string terminator. ST (9/12) indicates the end of a string. You can 
also use the equivalent 7-bit sequence, ESC (1/11) \ (5/12). 

The following is an example of a device control string. 



DCS 





1 


u 


% 5 


ST 


9/0 


3/0 


2/1 


7/5 


2/5 3/5 


9/12 


Device 


Para- 


Inter- 


Final 


Data 


String 


control 


meter 


mediate 




string 


terminator 


string 












introducer 













38 CHARACTER ENCODING 



This device control string assigns the DEC Supplemental Graphic set as the 
user-preferred supplemental set. 

Using Control Characters in Sequences 

You can use control characters — ESC, CAN. and SUB — to interrupt or re- 
cover from errors in escape sequences, control sequences, and device control 
strings. 

• You can send ESC (1/11) to cancel a sequence in progress and begin 
a new sequence. 

• You can send CAN (1/8) to indicate the present data is in error or 
to cancel a sequence in progress. The VT300 interprets the charac- 
ters following CAN as usual. 

• You can send SUB (1/10) to cancel a sequence in progress. The 
VT300 interprets the characters following SUB as usual. 

The VT300 does not lose data when errors occur in escape or control sequences 
and device control strings. The terminal ignores unrecognized sequences and 
strings, unless they end a current escape sequence. 

7-Bit Code Extension Technique 

You can represent all Cl control characters as 7-bit escape sequences. You can 
use the Cl characters indirectly, by representing them as 2-character escape 
sequences. ANSI calls this technique a 7-bit code extension. The 7-bit code ex- 
tension provides a way of using Cl characters in applications written for a 7-bit 
environment. Here are some examples. 



8-Bit 


7-Bit Code Extension 


Cl Character 


Escap 


e Sequence 


CSI 


ESC 


[ 


9/11 


1/11 


5/11 


SS3 


ESC 


O 


8/15 


1/11 


4/15 


IND 


ESC 


D 


8/4 


1/11 


4/4 


DCS 


ESC 


P 


9/0 


1/11 


5/0 



CHARACTER ENCODING 39 



In general, you can use the 7-bit code extension technique in two ways. 

• You can represent any Cl control character as a 2-character escape 
sequence. The second character of the sequence has a code that is 
40 (hexadecimal) and 64 (decimal) less than that of the the Cl 
character. 

• You can make any escape sequence whose second character is in the 
range of 4/0 through 5/15 one byte shorter by removing the ESC 
character and adding 40 (hexadecimal) to the code of the second 
character. This generates an 8-bit control character. For example, 
you can change ESC [ to CSI with this method. 

WORKING WITH 7-BIT AND 8-BIT ENVIRONMENTS 

There are three requirements for using one of the terminal's 8-bit character 
sets. 



• Your program and communication environment must be 8-bit 
compatible. 

• The terminal cannot be in national replacement character set mode 
(DECNRCM). 

• The terminal must operate in VT300 mode. When the terminal oper- 
ates in VT100 mode or VT52 mode, you are limited to working in a 
7-bit environment. 

The following sections describe conventions that apply in VT300 mode. 

Conventions for Codes Received by the Terminal 

The terminal expects to receive character codes in a form compatible with 8 -bit 
coding. Your application can use the CO and Cl control characters, as well as 
the 7-bit Cl code extensions, if necessary. The terminal always interprets these 
codes correctly. 

When your program sends GL or GR codes, the terminal interprets the charac- 
ter codes according to the graphic character sets in use. When you turn on or 
reset the terminal, you automatically select the DEC Multinational character 
set. This mapping assumes the current terminal mode is VT300 mode. 



40 CHARACTER ENCODING 



Conventions for Codes Sent by the Terminal 

The terminal can send data to an application in two ways. 

• Directly from the keyboard 

• In response to commands from the host (application or operating 

system) 

Most function keys on the keyboard send multiple-character control functions. 
Many of these functions start with CSI (9/11) or SS3 (8/15), which are Cl char- 
acters. If your application cannot handle 8-bit characters, you can make the 
terminal automatically convert all Cl characters to their equivalent 7-bit code 
extensions before sending them to the application. To convert Cl characters, 
you use the DECSCL commands described in Chapter 4. 

By default, the terminal is set to automatically convert all Cl characters sent 
to the application to 7-bit code extensions. However, to ensure the correct 
mode of operation, always use the appropriate DECSCL commands. 

NOTE: In VT300 mode, the terminal can send GR graphic characters to an 
application, even if the application cannot handle 8-bit codes. However, in a 
7-bit environment, the terminal sends Cl controls as 7-bit escape sequences and 
does not send 8-bit graphic characters. 

New programs should accept both 7-bit and 8-bit forms of the Cl control 
characters. 

DISPLAY CONTROLS MODE 

The VT300 lets you display control characters as graphic characters, when you 
want to debug your applications. In this mode, the terminal does not perform 
all control functions. 

To select this mode, you must set the Control Representation feature in the 
Set-Up Display screen to Display Controls. You cannot select this mode with 
an escape sequence. 

The effect of the Display Controls setting depends on the operating mode you 
use. 

In VT300 mode 

When you select Display Controls, the terminal temporarily loads a special 
graphic character set into CO, GL, Cl, and GR. Figure 2-9 shows this special 
set, called the display controls font. The terminal uses this font to display con- 
trol characters on the screen. 



CHARACTER ENCODING 41 



In VT52 or VT100 mode 

When you select Display Controls, the terminal temporarily loads the left half 
of the display controls font into CO and GL. The terminal uses this half of the 
font to display all CO and GL characters. {CI and GR are meaningless in VT52 
or VT100 mode.) 





COLUMN 





1 


2 


3 


4 


5 


6 


7 


ROW 


us BITS 

b7 
b6 

b5 
b4 b3 b? bl 










a 








1 




a 











1 
















N 

u 

L 








D 


20 
16 
10 


SP 


40 
32 
20 





60 
48 
30 


® 


100 
64 

40 


p 


120 

80 
50 


\ 


140 
96 
60 


P 


160 

112 
70 


1 


1 


\ 


i 


D 


21 
17 


I 


33 


1 


61 
49 

31 


A 


101 
65 


Q 


121 
SI 
51 


a 


(41 
97 
61 


q 


16! 
113 

71 


2 


10 


X 


2 
2 
2 


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22 
18 

12 


?i 


42 
34 
22 


2 


62 
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102 
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42 


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122 
82 
52 


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142 
88 
62 


r 


162 

72 


3 


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3 
3 


D 
C 
3 


23 
19 

13 


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43 
35 
23 


3 


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51 

33 


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103 
67 
43 


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83 
53 


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143 
99 
63 


s 


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115 
73 


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1.00 


T 


' 


\ 


24 
20 


$ 


44 
36 
24 


4 


64 
52 
34 


D 


104 
68 


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124 
84 

54 


d 


144 
100 
64 


t 


164 
116 

74 


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N 
Q 


5 
5 
5 


N 
A K 


25 
21 

15 


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25 


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65 
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105 
69 
45 


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125 
35 
55 


• 


145 

10. 
65 


u 


165 
117 

75 


6 


110 


A 
C 
K 


6 
6 
6 


N 


26 
22 

16 


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46 
38 

26 


6 


66 
64 

36 


F 


106 
70 
46 


V 


126 
86 
56 


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146 
102 
66 


V 


166 
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76 


7 


1 : 1 


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E 
L 


7 


E 
T 
B 


27 
23 


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47 
30 


7 


67 
55 
37 


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107 
71 
47 


w 


127 
87 
57 


9 


147 
103 

67 


w 


167 
119 

77 


8 


1 C 


1 


to 

8 
8 


C 

\ 


30 
13 


( 


50 
40 
23 


8 


m 

56 

38 


H 


110 
72 
48 


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130 
88 
58 


h 


150 
68 


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120 

78 


9 


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T 


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M 


31 
19 


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51 
29 


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57 
39 


I 


49 


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131 
89 
59 


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151 
105 
69 


y 


171 
121 
79 


10 


10 10 


L F 


12 
10 


c 


32 
26 

1A 


* 


52 
42 
2A 




72 
58 
3A 


J 


74 


z 


132 
90 


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152 
106 
6A 


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172 
122 
7A 


11 


10 11 


V 

T 


13 
11 
B 


E 
S 

c 


33 
2? 

IB 


+ 


53 
43 
2B 


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59 

3B 


K 


113 

75 
4B 


C 


133 
91 

5Q 


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153 
107 
66 


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173 
173 

7B 


12 


1 "l □ 


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F 


12 

C 


F 
S 


34 
23 
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2C 


< 


74 
60 
3C 


L 


76 
4C 


\ 


134 

92 
5C 


1 


154 
108 
GC 


1 


174 
124 
7C 


13 


110 1 


C R 


"5 
13 
D 


G 
S 


35 
29 
ID 


- 


55 
45 
20 


= 


75 
61 
3D 


M 


115 
77 
4LP 


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135 

93 


m 


155 
109 
60 


> 


175 

125 
7D 


14 


1110 


s 




16 
E 


R 
S 


36 
30 
IE 




56 
46 
2E 


> 


76 
62 
3E 


N 


116 
7B 
4E 


A 


136 
94 
5E 


n 


156 

HO 
6E 


~- 


176 
126 

7E 


15 




s 
1 


17 
15 
F 


% 


37 
31 
IF 


/ 


57 
47 
2F 


7 


77 
63 
3F 





117 
79 

4F 


- 


137 
96 
5F 


o 


15? 
Ill 
6F 


■* 


177 
127 
7F 



GL CODES 

"(ASCII GRAPHIC )" 



KEY 



Character 



ESC 


33 

27 
1B 



OCTAL 
DECIMAL 



MA-0893-83W 



Figure 2-9 Display Controls Font (Left Half) 



42 CHARACTER ENCODING 



Exceptions 

Some control functions still work in this mode. 

• LF, FF, and VT cause a carriage return and line feed (CR LF) that 
move the cursor to a new line. The terminal displays the LF, FF, or 
VT character before performing the new line function. 

• XOFF (DC3) and XON (DC1) maintain flow control, if enabled in 
set-up. The terminal displays the DC1 or DC3 character after per- 
forming the control function. 

• The terminal does not display SSU session management commands 
(Chapter 14). 



8 


9 


10 


11 


12 


13 


14 


15 


COLUMN 





D 













i 








i 









'\„BITS 

li6 

1)5 
64 b3 L2 61 


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139 
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D 
C 
S 


220 
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90 


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240 
160 
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260 
175 
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A 


300 
192 
CO 


*> 


320 

20a 

OD 


a 


340 
224 

EO 


% 


360 
240 
FO 


O Q 





8 

1 


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129 
81 


P 
U 
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221 
91 


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161 


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61 


r 
A 


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193 
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N 


321 
209 

01 


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rf 


361 
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92 


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242 
162 
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262 
178 
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A 


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194 
C2 





322 
210 
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A 

a 


342 
226 
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362 
242 
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1 


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8 
3 


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131 
33 


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93 


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179 

63 


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224 
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244 


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180 

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244 
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149 
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165 
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197 
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213 

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229 

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355 
245 
F5 


10 1 


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A 


206 
134 
86 


S 

"a 


226 

ISO 
96 


1 


246 
166 
A6 


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266 
182 
B6 


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306 
196 
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326 
214 
D6 


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346 
230 

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366 
246 
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O110 


6 


1 
A 


207 
135 
87 


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P A 


227 
151 
97 


§ 


247 
167 
A7 




267 
183 

a? 


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307 
199 
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327 
215 

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347 
231 
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247 

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111 


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T 
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210 
136 
88 


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230 
152 
98 


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217 
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233 

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249 
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138 
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232 

154 

9A 


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252 
170 
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272 
186 
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312 
202 
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332 
216 
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352 
234 

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250 
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139 

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155 

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253 
171 
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273 
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313 
203 

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333 

219 


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353 
235 

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373 
261 
FB 


10 11 


11 


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214 
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156 
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754 
172 

AC 


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274 
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BC 


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314 
2D4 

cc 


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334 
220 
DC 


1 


354 
236 
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374 
252 
FC 


110 


12 


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1 


215 
141 
GD 




s 
c 


235 
157 

90 


- 


265 
173 

AD 


Vi 


275 
1B9 
BD 


r 
1 


315 
205 
CD 


V 


335 
221 

nn 


w 
1 


355 
237 
ED 


y 


375 
253 
FO 


110 1 


13 


1 

2 


216 
142 
8E 


p 

M 


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158 
9E 


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256 
174 
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276 
190 
BE 


A 
1 


316 
206 
CE 


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336 
222 
DE 


A 


356 
238 
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I 


376 
254 
FE 


1110 


14 


\ 


217 
143 
8F 


A 


237 
159 
9F 


- 


257 

175 
AF 


L 


277 
191 
BF 


V 


317 
207 
CF 


JS 


337 
223 
DF 


V 


357 
239 

EF 


V 


377 
255 

FF 


, , , , 


15 



|- — CI CODES 



GR CODES 



ISO LATIN-1 SUPPLEMENTAL GRAPHIC 



MA-0401-86 



Figure 2-9 Display Controls Font (Right Half) 



CHARACTER ENCODING 43 



PART 2 

CONTROL FUNCTIONS 

SENT TO THE HOST 



KEYBOARD CODES 



3 



Keyboard Codes, 47 

Main Keypad, 48 
Standard Keys, 48 
Function Keys, 50 

Editing Keypad, 51 

Numeric Keypad, 52 

Top-Row Function Keys, 55 

7-Bit Control Codes, 55 
Special Cases, 58 

Local Editing Mode, 58 

Turning Autorepeat On and Off, 60 

Unlocking the Keyboard, 61 



This chapter describes the codes that the terminal can send to an application 
program. The chapter assumes that you are familiar with the character- 
encoding concepts described in Chapter 2. 

In VT300 or VT100 mode, the keyboard keys send codes that are compatible 
with ANSI standards. In VT52 mode, some keys send codes that differ from 
those sent in the ANSI-compatible modes. This chapter lists VT52 codes that 
differ from the ANSI-compatible codes. 

The terminal can use 16 different national keyboards. This chapter describes 
significant differences among the keyboards. 

KEYBOARD CODES 

The keyboard (Figure 3-1) has four groups of keys: a main keypad, an editing 
keypad, an auxiliary keypad, and the top-row function keys. 



47 



TOP ROW FUNCTION KEYS 



_ VISUAI , 

INDICATORS 



jRF^^yTlRRRRRr TlRRRrW^T lRRPR 




mm 
mm 

Em 




-MAIN KEYPAD- 



L—EDITING-J 
KEYPAD 



NUMERIC, 
KEYPAD 



V1A-0414-86 



Figure 3-1 Four Key Groups (North American/U.K. Keyboard) 

Main Keypad 

The main keypad has standard keys and function keys. You use the standard 
keys to send letters, numbers, and other symbols. You use the function keys to 
send special function codes. 

Standard Keys - The standard keys send alphanumeric characters. You must 
use more than one key to produce some special characters. 

Some standard keys vary on the different keyboards. On the North American/ 
United Kingdom keyboard, all standard keys are ASCII characters and send 
only ASCII codes. The North American/U.K. keyboard does not have any stan- 
dard keys that send DEC Supplemental Graphic or ISO Latin-1 supplemental 
characters alone. 

The North American/U.K. keyboard is a special case. Most other keyboards 
have some standard keys that send DEC Supplemental Graphic or ISO Latin-1 
supplemental characters, as well as ASCII characters. For example, many of 
the European keyboards have standard keys that send characters with accent 
marks or diacritical marks. 

You can create any DEC or ISO Latin-1 supplemental character that is not 
available on a standard key by typing a compose sequence. Chapter 6 of 
Installing and Using the VT330/VT34O Video Terminal explains how to use 
compose sequences. 



48 KEYBOARD CODES 



Each graphic character has a unique code. This code is always the same, no 
matter which keyboard you use or how many keys you press to create that 
character. The code is based on the character's position in the 8-bit code table 
(Chapter 2). 

You can use GL characters in a 7-bit or 8-bit environment. You can use GR 
characters only in an 8-bit environment. VT52 and VT100 modes are intended 
for use in 7-bit environments, as well as data exchange over a 7-bit host line. 
VT300 mode is intended for use in 8-bit environments, as well as data ex- 
change over an 8-bit host line. 

Some standard keys can work as data processing keys. Every keyboard except 
the North American/U.K. keyboard has some data processing keys. Data pro- 
cessing keys have three or four characters on the top of their keycap, rather 
than the normal two. The data processing keys send characters that are com- 
monly used in data processing applications. Figure 3-2 shows an example. 

You can select "Typewriter Keys" or "Data Processing Keys" in the Keyboard 
Set-Up screen. When you select "Data Processing Keys," the data processing 
keys send the character on the right side of their keycap. When you select 
"Typewriter Keys," they send the character on the left side of their keycap. 
You can select shifted (upper) character codes for these keys by holding the 
Shift key down. 



□Daannaaaaannnaa 




HE 



□□□ 
□En 
□□□ 
□□□ 


=t=\ 


10 | ■ 



MA-0990-86 



Figure 3-2 Standard Key with a Data Processing Character 
(French/Belgian Keyboard) 



KEYBOARD CODES 49 



Function Keys - This section describes the function keys on the main keypad. 
Remember, the column/row numbers that appear after a character tell you the 
position of the character in the code table (Chapter 2). For example, the DEL 
character is at column 7/ row 15. 



Key 
<X] 



Tab 
Return 



Ctrl 
Lock 



Shift 
(2 keys) 

Space bar 

Compose 
Character 



Function 

The <X] key sends a delete character (DEL, 7/15) or a 
backspace character (BS, 0/8), depending on the backar- 
row key mode selected. You can select the mode by 
using set-up or a control function. 

The Tab key sends a horizontal tab character (HT, 0/9). 

The Return key sends either a carriage return (CR, 
0/13), or a carriage return (CR, 0/13) and line feed (LF, 
0/10), depending on the state of line feed/new line mode 
(LNM). See Chapter 11. 

The Ctrl key alone does not send a code. You use Ctrl 
with another key to send a control code. 

The Lock key alone does not send a code. You use 
Lock to set or clear the "caps lock" or "shift lock" 
state. You select "caps lock" or "shift lock" in the 
Keyboard Set-Up screen. 

The Shift key alone does not send a code. 

You use Shift with another standard key, to send the 

top character shown on the key. 

The space bar sends a space character (SP, 2/0). 

The Compose Character key does not send a 
code. Pressing Compose Character starts a compose se- 
quence. You can use compose sequences to create char- 
acters that do not appear on any single key (such as 
characters from the DEC Supplemental Graphic set). 
You can disable the Compose Character key in set-up. 
See Installing and Using the VT330/VT340 Video 
Terminal. 



50 KEYBOARD CODES 



Editing Keypad 

The editing keypad includes the editing keys and arrow keys. Table 3-1 lists 
the codes sent by the editing keys, and Table 3-2 lists the codes sent by the 
arrow keys. Normally, you use the arrow keys to control the cursor on the 
screen. 

Table 3-1 Codes Sent by Editing Keys 

Code Stmt 



Key 


VT300 Mod 


e 


VTJ.00, VT52 Mi»d«s 


Find 


CSI 


1 


■- 


The editing keys do not 




9/11 


3/1 


7/14 


send codes in these two 
modes. 


Insert Hers 


CSI 


2 


~ '.':..' 






9/11 


3/2 


7/14 




Remove 


CSI 


3 








9/11 


3/3 


7/14 




Select 


CSI 


4 


. 






9/11 


3/4 


7/14 




Prev Screen 


CSS 


5 


-'.■■■ 






9/ .; 1 


3/5 


7/14 




Next Screen 


CSF 


6 


: '~ y 






9/11 


3/6 


7/14 





KEYBOARD CODES 51 



Table 3-2 Codes Sent by Arrow Keys 

Cursor Key Mode Setting (DECCKM) 

: : ' ANSI Mode . : " : ' VT52 Modu* ■ 



Key 


Cursor 


Applicaliou 


m 


CSI 


A 


SS3 


A 




9/11 


4/1 


8/1 5 


4/1 


m 


CS? 


B 


SS3 


B 




9/11 


4/2 


8/1 ft 


4/2 


\-~ »[ 


CSI 


C 


SS3 


C 




9/11 


4/3 


8/: 5 


4/3 


E3 


CSI 


D 


SS3 


D 




9/1 1 


4/4 


8/15 


4/4 



Cursor 

ESC 
1/1 J 



Application 



A 

4/1 



ESC B 

1/11 4/2 

ESC C 

1/11 4/3 

ESC D 

1/11 4/4 



ESC 
1/11 

ESC 
1/1 i 

ESC 

1/11 

ESC 
1/11 



A ■ 

4/1 

B 

4/2 

: e' 

4/3 

D 

4/4 



* ANSI mode applies to VT300 and VT100 modes. VT52 mode is not compati- 
':■' ble with ANSI mode. ■ 

Numeric Keypad 

The characters sent by the numeric keypad depend on the setting of VT52 
mode and keypad numeric mode. The application usually selects the application 
keypad codes. However, you can select the application keypad codes in the 
Keyboard Set-Up screen. See Chapter 11 for more information about the nu- 
meric keypad. 

Table 3-3 lists the character codes sent by the numeric keypad in ANSI modes 
(VT100 and VT300) and in VT52 mode. 



52 KEYBOARD CODES 



Table 3-3 Codes Sent by Numeric Keypad Keys 
Keypad Mode Setting (DECNKM) 





ANSI Mode* 






VT52 Mode* 






Key 


Numeric 


Application 


Numeric 


Application 








SS3 


P 





ESC 


■ P 




3/0 


8/15 


7/0 


3/0 


1/11 


3/15 7/0 


1 


1 


SS3 


q 


1 


ES€ 


? q 




3/1 . 


8/15 


7/1 


3/1 


1/11 


3/15 7/1 


2 


2 


S3 


r : 


2 


ESC 


? r 




3/2 


8/15 


7/2 


3/2 


1/11 


3/15 7/2 


3 


3 


SS3 


s 


3 


ESC 


? s 




3/3 


3/15 


7/3 


3/3 


1/11 


3/15 7/3 


4 


4 


SS3 


t 


4 


ESC 


? t 




3/4 


8/15 


7/4 


3/4 


1/11 


3/15 7/4 


5 


5 


SS3 


u 


5 


ESC 


? u 




3/5 


8/15 


7/5 


3/5 


1/11 


3/15 7/5 


6 


6 


SS3 


V 


6 


ESC 


? V 




3/6 


8/15 


7/6 


3/6 


l.'ll 


3/15 7/6 


7 


7 


SS3 


w 


££:&$:^&s'K 


ESC 


? w 




3/7 


8/15 


7/7 


3/7 


I'll 


3/15 7/7 


8 


8 


SS3 


x 


8 . 


ESC 


? X 




3/8 


8/15 


7/8 


3/8 


1/11 


3/15 7/8 


9 


9 


SS3 


y 


9 


ESC 


? .v 




3/9 


8/15 


7/9 


3/9 


1/11 


3/15 7/9 



ANSI mode applies to VT300 and VT100 modes, 
patible with ANSI standards. 



VT52 mode is not com- 



KEYBOARD CODES 53 



Table 3-3 Codes Sent by Numeric Keypad Keys (Cont) 

Keypad Mode Setting (DECNKM) 
.".: ; ' ANSI Mode* VT52Mode* 



Key 


Numeric 


Application 


Numeric 


Application 




-■"■ 


(minus) 


SS3 


m 


'.■■■'■ 




ESC 


? 


m 




2/13 


8/15 


6/13 


2/13 




1/11 


' 3/15 


6/13} 


♦ 


(comma) 


SS3 


1 


■V 




ESC 


? 


1 




2/12 


8/15 


6/12 ' 


/ 2/12 




1/11 


3/15 


6/12} 


. 


(period) 


SS3 


■ n ■ 


. # 




ESC 


? 


n 




2/14 


8/15 


6/14 


2/14 




1/11 


3/15 


6/14 


Enter 


CR or 


SS3 


M 


CRor 


ESC 


? 


M 




0/13 


8/15 


4/13 


0/1 3 




1/11 


3/15 


4/13 




■ CR LP 






CR 


LF | 










0/130/10 






0/13 0/10 








PF1 


SS3 P 


SS3 


P 


ESC 


P 


ESC 


P 






8/15 5/10 


8/15 


5/0 


1/11 


5/0 


1/11 


5/0 




PF2 


SS3 Q 


SS3 


Q 


ESC 


Q 


ESC 


Q 






8/15 5/1 


8/15 


5/1 


1/11 


5/1 


1/11 


5/1 




PF3 


SS3 R 


SS3 


R 


ESC 


R 


ESC 


R 






8/15 5/2 


8/15 


5/2; ■' - 


1/11 


5/2 


1/11 


5/2 




PF4 


SS3 S 


SS3 


S 


ESC 


S 


ESC 


S 






8/15 5/3 


8/15 


5/3 


1/11 


5/3 


1/11 


5/3} 





* ANSI mode applies to VT300 and VT100 modes. VT52 mode is not com- 
patible with ANSI standards. 

| You cannot use these sequences im a VT52 terminal. 

=(= Keypad numeric mode. Enter sends the same codes as Return. You can use 
line feed/new line mode (LNM) to change the code sent by Return. When 
LNM is reset, pressing Return sends one control character (CR). When 
LNM is set. pressing Return sends two control characters (CR. LFI. 



54 KEYBOARD CODES 



Top-Row Function Keys 

There are 20 top-row function keys, Fl through F20. The first five keys — 
labeled Hold Session, Local Print, Set-Up, Switch Session, and Break — are lo- 
cal function keys that do not send codes. You use these keys to perform prede- 
fined functions local to the terminal. Keys F6 through F20 send the codes 
listed in Table 3-4. For more information, see Chapter 4 of Installing and 
Using the VT330/VT340 Video Terminal. 

7-Bit Control Characters 

Table 3-5 lists the key or keys you use to send each 7-bit control characters. 
This table applies to all keyboards. The 7-bit control characters are the CO 
characters. You cannot send 8-bit CI control characters from the keyboard. 

Table 3-4 ' '■■ ■■■'. Codes Scut by the Top-Row Function Keys .-. ' -^ ■ '/^ 

■;/: ■ Code Sent 



Name on 
Legend Strip 

Hold Session 

Local Print 

Set-Up 

Switch Session 

Break 



Key 
Number 

(Fl)* 

(F2)* 

(F3t* 

(F4I* 

IF5)* 



VT30O Mntlr 



VT100. 
VT52 Modes 



F7 






F7 



CSI 

9/11 


i 
3/1 


7 
3/7 


7/14 


CSI 

9/11 


I 
3/1 


■8 


7/14 



* Fl through F5 are local function keys that do not send codes. 



KEYBOARD CODES 55 



Table 3-4 Codes Sent by the Top-Row Function Keys (Cont) 

Code Sent 



Name on 
Legend Strip 


Key 
Number 


VT300 Mode 






VT100, 
VT52 Modes 


F8 


PS 


CSI 

9/11 


1 

3/1 


9 

3/9 


7/14 


- . ;■ ■ ■;.■ ■■ ■ -^-U^ ■ /■ /- .-■ " v - -vv V^ 


F9 


F9 


CSI 

9/11 


2 

3/2 




3/0 


7/14 


: '(<.-'; : -* : ;'■'..' 


F10 


F10 


CSI 

9/11 


2 

3/2 


1 

3/1 


7/14 


\' : >,,/'^-- : :' 


Fll (ESC) 


Fll 


CSI 

9/11 


2 

3/2 


3 
3/3 


7/14 


ESC 

1/11 


F12IBS) 


F12 


CSI 

9/1 J 


2 

3/2 


4 
3/4 


7/14 


BS 

0/8 


F13 (LF) 


F13 


CSI 

9/11 


2 

3/2 


5 

3/5 


7/14 


LF 

0/10 


F14 


F14 


CSI 

9/1 ! 


2 

3/2 


6 

3/6 


7/14 


■'•'■■ ■ — 


Help 


;.. F15 


CSI 

9/11 


2 

3/2 


8 
3/8 


7/14 


:;;:■■:■— - :-;.; 


Do 


F16 


CSI 

9/11 


2 

3/2 


9 

3/9 


7/14 


— 


F17 


F17 


est 

9/11 


3 

3/3 


1 

3/1 


7/14 


'. .'— .'■':■ 


F18 


F18 


CSI 

9/11 


3 

3/3 


2 

3/2 


7/14 


'■ _ 


F19 


F19 


CSI 

9/1 1 


3 

3/3 


3 

3/3 


7/14 


■ — 


F20 


F20 


CSI 

9/11 


3 

3/3 


4 

3/4 


7/14 


— 



56 KEYBOARD CODES 



Table 3-5 Keys Used to Seucl 7-Bit Control Codes 



Control 


Code 






Character 


Table 


Key Pressed With 


Dedicated 


Mnemonic 


Position 


Ctrl (All Modes) 


PuuttioiJ Key 


NUL 


0/00 


2 or space bar 


'■'■.'—'■.■'. 


SOH 


0/01 


'-A '■;■■■ .' 


^^:^ : h^W^0 : W : : 


STX 


0/02 


B 


':;:;v:' :: ;--v : '.;:^' : ;;';;.:;:.-;' :: :-:' : 


ETX 


0/03 


'€."'.■' 


^•^^■■■ : .:h!B: : fS : i 


EOT 


0/04 


D 


i^^-^i^yM^ 


ENQ 


0/05 


E 


■■■.—'■.■'■.■' 


ACK 


0/06 


. F 


; H :l : S^SStJv 


BEL 


0/07 


■o 


■■:: ; :::vV--'^ : ; ; ;v : .'.'- ; --:;'.:' ; X ; -- 


HS ■ . 


0/08 


II 


F12IBSI* 


HT 


0/09 


■ ■ I '.-.'' 


Tab 


LI 7 


0/10 


"J. ■ ' 


F13 (LF)* 


VT 


0/11 


K 


^■^WK'U;: 


IT 


0/12 


L 


S^XV^V^:^ 


CR 


0/!M 


M 


Return 


SO 


0/14 


■ "-N- '"'■'.''■■'.'■ ' 


^X^a^l^^vW : 


SI 


0/15 


.0 


"0M^M^:i:^:^ 


DLE 


1/00 


P 


v^|Xrloi5X. ; 'X ; XH 


DC1 


1/01 


Q{ 


'■' ;: - ; : :; .: : ^- : ;r:' ::; . : .'.'' : .'" ; ' v . : ' : '' 


DC2 


1/02 


R 


:" : -:V: ; ^^X:;;:i(VX;E,fe; 


DC3 


1/03 


S| 


^'v:;: : -:^-;" ; . ; 


DC4 


1/04 


T 


';;.;':■■■'. :;^;- ; :^.;V:>';'::::' : -'.:V;./ : ' 


NAK 


1/05 


u. ■ ' . ■ ' ■ 


^J^^^.' 


SYN 


1/06 


V 


■ ; SrKA^^^ : : ; ;.:^- : -^V;f 


ETB 


1/07 


w 


W:. ; SS^: -il^v /';:■; v;^;;; 


CAN 


1/08 


' x ■'■.-. ■ 


^S^^^Vir^^?-^^ 


EM 


1/09 


MM'&MMWM'M: 


■';::: ! : ; -V:':'ffi:':- : : ;; X3;: : : ; : ;: : : .:0:i ; . :; 


SUB 


1/10 


"■■■■%■ .■'■■■■'■'"".''■'.' 


IfeS&S^CXX^SS 


ESC 


1/11 


3or{ 


Fll (ESC)* 


FS 


1/12 


4or/ 


''^^■xf'^^--^^ 


GS 


1/13 


■ 5 or]. 


: :j. ; ; ; \ ; ;;-~ ; - ; : ) :;:; 


RS 


■ 1/14 


6or~ 


: S^§2^S : :^Vv^ 


US 


1/15 


7 or? 


'■;;■ : :: --; ; ';.. 


DEL 


7/15 


8 ' 


Delete 



* 7-bit control codes sent in VT100 and VT52 modes only. 

} 7-bit control codes sent only when XON/XOFF support is off. 



KEYBOARD CODES 57 



SPECIAL CASES 

This section describes special functions and modes that affect the keyboard. 

Local Editing Mode 

When the terminal is in local editing mode, certain keys on the editing and 
numeric keypads have local editing functions. Table 3-6 lists the local editing 
keys. 

See Chapter 9 for details on local editing mode. Chapter 9 of Installing and 
Using the VT330/VT340 Video Terminal describes the local editing keys. 

Table 3-6 ' : y- -$Mfs Affected By Loral Editing Mode ; : 



Interactive Mode 


Locat Editing Mode 




Name on Top 


Name on From 


. Local Editing ■, ; ■ 


of Key 


of Key or Template 


' Function ' 


Return 




If DECLNM is set. sends a block 








of text to the host. 


Find 


Home Cursor 


Moves the cursor to the top left 
corner of the scrolling region. 


fnsy.-t Hero 


Insert/Overstrike 


Switches between insert and 
overstrike modes {Chapter 8). 


Remove 


CLR PAGE* 


Erases the characters 




Clr Field 


on the current page, or erases the 



characters in a field. 



To select this function, you press the Shift key and this key. 



58 KEYBOARD CODES 



Table 3-6 Keys Affected By Local Editing Mode 
Interactive Mode Local Editing Mode 



Name on Top 
of Key 

Select 



Prev Screen 
Next. Screen 

PF1 



PF2 
PF3 
PF4 



Enter 



Name era Front 
of Key or Template 

EDIT* 



Prev P;iiy 
Next Page 



Tab[<— * 

->i 



Insert Line 
Delete Line 
Delete Char 
(Space) 

Transmit 



Local Editing 
Function 

Switches the terminal between 
interactive mode and local editing 
mode. 

Displays the previous page in 
page memory on the screen. 

Display.; the next page in ^age 
memory on the screen. 

Tabs to the next 
unprotected field or 
tab stop. 

Shift-Tab tabs to the 
previous unprotected 
field or tab stop. 

Inserts a line of character posi- 
tions on the page. 

Deletes a line of character posi- 
tions from the current page. 

Deletes a character from the cur- 
rent page. 

Inserts a space character or a 
comma, depending on the setting 
of the Keypad comma feature in 
Keyboard Set-Up. 

Sends a block of characters to 
the host. 



* To select this function, you press the Shift key and this key. 



KEYBOARD CODES 59 



Turning Autorepeat On and Off 

The autorepeat feature makes most keys send their character repeatedly when 
you hold the key down. You can turn the autorepeat feature on and off by 
using the Keyboard Set-Up screen or the DECARM control function (Chapter 
11). 

The following keys do not repeat: Hold Session, Local Print, Set-Up, Switch 
Session, Break, Compose Character, Shift, Return, Lock, and Ctrl. Shifted keys 
and keys pressed with Ctrl can repeat. When the terminal is in edit mode, the 
editing keys listed in Table 3-6 do not repeat. 

Keys that can auto repeat usually start repeating after a delay of 0.5 seconds. 
The autorepeat speed depends on the baud rate of the host system and the 
type of key. At speeds of 2400 baud or above, all keys repeat 30 times per 
second. At lower speeds, the keyboard is divided into three groups. 

Group A Main keyboard 

Group B Cursor keys and keypad keys 

Group C Top-row function keys and editing keys 

The keys in each group repeat at the fixed rate set by the baud rate of the 
host, regardless of how many codes the key actually sends. 



lost 


Autorepeat Rate (Chare 


cters 


aud Rate 


Group A 


Group B 


Gro 


2400 


30 


30 


30 


1200 


30 


30 


24 


600 


30 


20 


12 


300 


30 


12 


12 


150 


6 


6 


6 


110 


6 


6 


6 


75 


6 


6 


6 



In general, the Transmit Rate Limiting feature in the Communications Set-Up 
screen does not affect repeat rates. The terminal can send codes at the speed 
of 150 characters per second at most baud rates. In local mode, keys repeat at 
30 keystrokes per second. 

Unlocking the Keyboard 

Two conditions can cause the keyboard to lock. 

• An application sends a control function to set the keyboard action 
mode (KAM), as described in Chapter 11. 

60 KEYBOARD CODES 



• The keyboard input buffer is full. 

When the keyboard is locked, all keys except Hold Session, Local Print, 
Set-Up, Switch Session, and Break are disabled. Also, the keyboard's Wait indi- 
cator turns on. 

Any of the following events can unlock the keyboard. 

• The output buffer becomes less than full (assuming KAM is not set). 

• The terminal receives KAM when the output buffer is not full 
(Chapter 11). 

• You select Clear Communications, Reset Session, or Recall Factory 
Default Settings from the Set-Up Directory screen. (Entering set-up 
unlocks the keyboard. If you do not select one of these functions in 
set-up, the keyboard locks again when you leave set-up.) 

• The terminal performs the power-up self-test (DECTST) or a hard 
reset (RIS). See Chapter 13. 



KEYBOARD CODES 61 



PART 3 

CONTROL FUNCTIONS 

RECEIVED FROM THE HOST 



EMULATING VT SERIES TERMINALS 



4 



Level 1 (VT100 Mode), 66 

Level 3 (VT300 Mode), 66 

All Levels, 66 

Selecting an Operating Level, 68 

Sending CI Controls to the Host, 69 

Select 7-Bit Cl Control Characters (S7C1T), 69 
Select 8-Bit Cl Control Characters (S8C1T), 69 

National Replacement Character Set Mode, 70 



The VT300 terminal can operate like VT200, VT100, and VT52 series termi- 
nals. This feature lets you use the VT300 with applications designed for these 
terminals. You can select from two possible levels of operation. 

Level 1 for VT100 operation 

Level 3 for VT200 and VT300 operation (default) 

When you operate the terminal at level 1, you cannot use some VT300 control 
functions. Table 4-1 lists the functions you cannot use. 

The following paragraphs describe other limits that apply to each operating 
level. The chapter also describes how to select an operating level and how to 
send 7-bit or 8-bit Cl controls to the host. 

Appendix A describes how to use VT52 mode. 

NOTE: Level 3 includes level 2 (VT200 operation). Applications designed for 
level 2 will run in level 3. 



65 



LEVEL 1 (VT100 Mode) 

The following limits apply to operating level 1. 

• The keyboard only sends 7-bit ASCII characters. 

• The terminal interprets keystrokes that send DEC Supplemental 
Graphic or ISO Latin-1 supplemental characters as errors. 

• The following keys do not operate. 

— special-function keys, except Fll (ESC), F12 (BS), and F13 (LF) 

— six editing keys 

— user-defined keys 

• Only the ASCII, national replacement (NRC), and DEC Special 
Graphic character sets are available. 

• Soft character sets are not available. 

• The terminal sets the eighth bit of all received characters to 0. 

• The terminal sends all CI control characters as 7-bit escape se- 
quences (ESC Fe). 

LEVEL 3 (VT300 Mode) 

In VT300 mode, you can use all VT300 features. This mode is fully compatible 
with Digital's VT200 series terminals. All keyboard functions are available. You 
can use all control functions and device control strings described in this 
manual. 

ALL LEVELS 

You can use the following features at any operating level. 

Printer port 

Edit mode (DECEDM) and the keyboard editing functions 

Status line (You can enable or change the status line at any level.) 

Session management 

User windows 



66 EMULATING VT SERIES TERMINALS 



Table 4-1 Control Functions Ignored in Level 1 (VT100 mode) 



Mnemonic 


Name 


DECCIR 


Cursor information report 


DECCTR 


Color table report 


DECDLD 


Down-line-loadable set 


DECRPDE 


Report displayed extent 


DECRPM 


Report mode 


DECRPSS 


Report selection or setting 


DECRQDE 


Request displayed extent 


DECRQM 


Request mode 


DECRQPSR 


Request presentation state 


DECRQSS 


Request selection or setting 


DECRQTSR 


Request terminal state 


DECRSPS 


Restore presentation state 


DECRSTS 


Restore terminal state 


DECSASD 


Select active status display 


DECSCA 


Select character attribute 


DECSED 


Selective erase in display 


DECSEL 


Selective erase in line 


DECSSDT 


Select status display type 


DECSTR 


Soft terminal reset 


DECTABSR 


Tabulation stop report 


DECTSR 


Terminal state report 


DECUDK 


User-defined keys 


DSR 


Locator device port 


DSR 


UDK and keyboard language 


ECH 


Erase character 


ICH 


Insert character 


LS2 


Locking shift 2 


LS3 


Locking shift 3 


LS1R 


Locking shift 1 right 


LS2R 


Locking shift 2 right 


LS3R 


Locking shift 3 right 


S7C1T 


Send 7-bit Cl controls 


S8C1T 


Send 8-bit Cl controls 



EMULATING VT SERIES TERMINALS 67 



SELECTING AN OPERATING LEVEL (DECSCL) 

You select the terminal's operating level by using the following select compati- 
bility level (DECSCL) control sequences. The factory default is level 3 (VT300 
mode, 7-bit controls). 

NOTE: When you change the operating level, the terminal performs a hard re- 
set (RIS). See Chapter 13 for details. 

Sequence Level Selected 



CSI 


6 


1 


If 


P 






Level 1 
VTluO mode 


9/11 


3/6 


3/1 


2/2 


7/0 






Level 3* 


CSI 


6 


2 


a 


P 






VT300 mode, 8-bit controls 


9/11 


3/6 


3/2 


2/2 


7/0 








CSI 


6 


2 


* 





II 


P 


VT300 mode, 8-bit controls 


9/11 


3/6 


3/2 


3/11 


3/0 


2/2 


7/0 




CSI 


6 


2 


» 


2 


a 


P 


VT300 mode, 8-bit controls 


9/11 


3/6 


3/3 


3/11 


3/2 


2/2 


7/0 




CSI 


6 


3 


II 


P 






VT300 mode, 8-bit controls 


9/11 


3/6 


3/3 


2/2 


7/0 








CSI 


6 


3 


) 





II 


P 


VT300 mode, 8-bit controls 


9/11 


3/6 


3/3 


3/11 


3/0 


2/2 


7/0 




CSI 


6 


3 


) 


2 


a 


P 


VT300 mode, 8-bit controls 


9/11 


3/6 


3/3 


3/11 


3/2 


2/2 


7/0 




CSI 


6 


2 


) 


1 


a 


P 


VT300 mode, 7-bit controls 


9/11 


3/6 


3/2 


3/11 


3/1 


2/2 


7/0 


(default) 


CSI 


6 


3 


? 


1 


a 


P 


VT300 mode, 7-bit controls 


9/11 


3/6 


3/3 


3/11 


3/1 


2/2 


7/0 


(default) 



* Level 3 includes level 2. 



68 EMULATING VT SERIES TERMINALS 



SENDING C1 CONTROLS TO THE HOST 

The VT300 can send CI control characters to the host as single 8-bit charac- 
ters or as 7-bit escape sequences. You should select the format that matches 
the operating level you are using. You can use the following sequences to select 
the format for Cl control characters. See Chapter 2 for information on working 
with 7-bit and 8-bit environments. 

Select 7-Bit C1 Control Characters (S7C1T) 

The following sequence causes the terminal to send all Cl control characters as 
7-bit escape sequences. 

ESC sp F 

1/11 2/0 4/7 

This sequence changes the terminal mode as follows. 
Mode Before Mode After 



VT300 mode, 8-bit controls 
VT300 mode, 7-bit controls 

VT100 mode or VT52 mode 



VT300 mode,7-bit controls. 
Same. Terminal ignores sequence. 

Same. Terminal ignores sequence. 



Select 8-Bit C1 Control Characters (S8C1T) 

The following sequence causes the terminal to send Cl control characters to 
the host as single 8-bit characters. 

ESC sp G 

1/11 2/0 4/6 



This sequence changes the terminal mode as follows. 
Mode Before Mode After 



VT300 mode, 8-bit controls 
VT300 mode, 7-bit controls 

VT100 mode or VT52 mode 



Same. Terminal ignores sequence. 
VT300 mode, 8-bit controls. 

Same. Terminal ignores sequence. 



EMULATING VT SERIES TERMINALS 69 



NATIONAL REPLACEMENT CHARACTER SET MODE 
(DECNRCM) 

The terminal has twelve 7-bit character sets for different national languages. 
Only one national replacement character set is available at a time. 

To use an NRC set, you must select national replacement character set mode. 
When you reset this mode, the terminal uses the DEC Multinational or ISO 
Latin-1 character set. 

Default: Multinational 



Mode 


Sequence 








Function 


Set 
(national) 


CSI ? 

9/11 3/15 


4 
3/4 


2 

3/2 


h 

6/8 


The terminal uses 7-bit 
characters from an NRC set 


Reset 
(multi- 
national) 


CSI ? 

9/11 3/15 


4 
3/4 


2 

3/2 


1 

6/12 


The terminal uses 7-bit 
and 8-bit characters 
from the DEC Multinational 
or ISO Latin-1 set. 



Notes on DECNRCM 



When DECNRCM is reset, the VT300 operates as a level 3 termi- 
nal. The terminal can send and receive 8-bit characters from the 
DEC Multinational or ISO Latin-1 character set. 

When DECNRCM is set (national), the VT300 operates as a level 3 
terminal. However, the terminal can only send and receive 7-bit 
characters. Also, the terminal uses one of the national replacement 
character sets. 

Setting DECNRCM causes the terminal to change character sets to 
their default state (at power-up or reset). 

If the North American/U.K. keyboard is currently selected in set-up, 
the terminal ignores DECNRCM. 



70 EMULATING VT SERIES TERMINALS 



USING CHARACTER SETS 



5 



Selecting Character Sets, 72 

Designating Character Sets (SCS Sequences), 73 

Mapping Character Sets, 76 
Locking Shifts, 78 
Single Shifts, 79 

National Replacement Character Sets, 79 

Preferred Supplemental Character Sets, 80 

ANSI Conformance Levels, 80 
Soft Character Sets, 82 

Designing a Soft Character Set, 82 

Coding the Soft Character Set, 84 

Down-Line-Loading Soft Characters. 90 

Designating the Soft Character Set, 97 

Soft Character Set Example, 98 

Clearing a Soft Character Set, 101 



This chapter describes how you can select different character sets to use with 
your VT300 terminal. This chapter assumes you are familiar with the character- 
encoding concepts described in Chapter 2. 

You can use two types of character sets in the terminal, hard sets and soft 
sets. Hard character sets are the character sets built into the VT300, such as 
the ASCII and DEC Supplemental Graphic sets. Soft character sets are sets 
that you down-line-load into the terminal from a host computer. You can design 
your own soft character sets. 



71 



The VT300 has seven hard character sets. However, the number of hard sets 
available depends on the operating mode you select, VT100 or VT300 (Chapter 
4). Table 5-1 lists the hard character sets you can select at each operating 
level. VT300 mode supports VT200 operation. 

Table 5-1 Character Sets Available 





' Level 1 


Level 3 




(VT100 mode) 


(VT300 mode) 


ASCII 


Yes 


All character 


DEC Supplemental Graphic 


No 


sets are 


ISO Latin- 1 supplemental 


No 


available. 


User-preferred supplemental 


No 




National replacement (NRCs) 


Yes 




DEC Special Graphic 


Yes 




DEC Technical 


No 




Soft character sets (DRCS) 


No 





SELECTING CHARACTER SETS 

To understand how to select character sets, you must first understand the 
function of the terminal's in-use table. The in-use table contains the character 
sets the terminal can currently access. You can place any two character sets in 
the terminal's in-use table. The in-use table consists of the graphic left (GL) 
and graphic right (GR) logical tables. 

Each time you turn on the terminal, the terminal places the following default 
character sets into the in-use table. 

ASCII in GL 

DEC Supplemental Graphic (or ISO Latin-1 supplemental) in GR 

The ASCII and DEC Supplemental Graphic sets together make up the DEC 
Multinational set. 

You can select a different character set by following these two steps. 

1. Designate the set as GO, Gl, G2, or G3. 

GO through G3 are logical sets that the terminal uses to access 
character sets. You can designate up to four character sets and have 
them ready for use in the in-use table. 

2. Map the designated set into the in-use table. 

After you map the set into the in-use table, you can display or send 
any character from that set using 8-bit codes. 

72 USING CHARACTER SETS 



Figure 5-1 shows how you select character sets. The following sections describe 
the control functions you use to designate and map character sets. 



IN-USE TABLE 



MAPPING 

FUNCTIONS: L 

LOCKING 
SHIFTS AND 
SINGLE SHIFTS 




DESIGNATING 

FUNCTIONS 

(SCS) 



VT300 CHARACTER SETS 



ASCII 

DEC SUPPLEMENTAL 1 

ISO SUPPLEMENTAL J 

NRC SETS 

DEC SPECIAL GRAPHIC 

DEC TECHNICAL 

DOWN-LINE-LOADABLE 



USER- PREFERRED 
SUPPLEMENTAL 



MA-0070-86 



Figure 5-1 Character Set Selection 



Designating Character Sets (SCS Sequences) 

You designate a hard character set as GO through G3 by using a select charac- 
ter set (SCS) escape sequence. You cannot designate a 96-character set as GO. 

SCS sequences use the format shown in Table 5-2. The table lists the code 
used to select each available character set. 

NOTE: The ISO Latin-1 supplemental character set is the only 96-character 
hard set available in the terminal. All other hard sets have 94 characters. 



USING CHARACTER SETS 73 



Table 5-2 Designating Character Sets 



ESC 


liiteu*.v.H)hiw 


1/1 1 


******** 


Intermediate 


Final 


To Select Use 


To Select 


94-Character Sets 


ASCII 



Final 

**** 



GO 



Gi 



G2 



G3 



2/8 



2/9 



2/10 



+ 
2/1 1 



96-Character Sets 



Gl 

G2 
G3 



2/13 

2/14 

l 

2/15 



DEC Supplemental 

Graphic ■ 

ISO Latin-1 
supplemental 
(96 characters) 

User-preferred 
supplemental 
(VT300 mode only) 



Use 

B 

4/2 



2/5 3/5 

A 

4/1 



< 

3/12 



DEC Special Graphic 

3/0 



DEC Technical 



> 

3/14 



National Replacement Character Sets* 



Rrir.ish 



Dutch 



A 

4/1 

4 
3/4 



Only one national character set is available at a time. You must select 
national mode to use national character sets. See "National Replacement 
Character Sets" in this chapter. 

Digital recommends using the first code shown. 



74 USING CHARACTER SETS 



Table 5-2 Designating Character Sets (Cont) 



Intermediate 



Final 



To Select 



Use 



To Select 


Use 




National Replacemen 


' Character Sets (Contf* 


Finnish} 


5 or 


C 




3/5 


4/3 ■ 


French 


R 

5/2 




French Canadian! 


9 or Q 

'H9 5/1 




German . 


K 

4/11 




Italian 


Y 

5/9 




Norwegian/Danish} 


or 


E or 6 




6/0 


4/5 3/6 


Portuguese 


% 6 

2/5 3/6 




Spanish 


Z 

5/10 




Swedish! 


7 or 


11 




3/7 


4/8 


Swiss 


.'/=.'. ;'V 





3/18 

Only one national character set is available at a time. You must select 
national mode to use national character sets. See "National Replacement 
Character Sets" in this chapter. ; ■ '■■■\.-; : ' ; . ; ;; 

Digital recommends using the firsl cole shown. 



USING CHARACTER SETS 75 



Examples 

• The following sequence designates the DEC Special Graphic charac- 
ter set as the Gl logical set. 

ESC)0 

• The following sequence designates the ISO Latin-1 supplemental 
character set as the G3 logical set. 

ESC /A 

Mapping Character Sets 

After you designate a character set as GO, Gl, G2, or G3, you must map the 
set into the in-use table as GL or GR. To map a set, you use locking-shift or 
single-shift control functions. 

Figure 5-2 shows how you use locking shifts and single shifts in VT100 mode. 
Figure 5-3 shows how you use locking shifts and single shifts in VT300 mode. 



IN-USE TABLE 



MAPPING 

FUNCTIONS 

V_/ LSO (SI) 

^J LS1 (SO) 

© SS2 

Q SS3 



CO 



L 




1) 2) 3) (4 



GO 



G1 



DESIGNATING 
FUNCTIONS (SCSI 









G2 



ESC ( FINAL 



ESC) FINAL 




VT300 CHARACTER SETS 
(7- BIT ONLY) 

ASCII 

DEC SPECIAL GRAPHIC 

ALL NRC SETS 



MA-0071-86 



Figure 5-2 Designating and Mapping Character Sets 
in VT100 Mode 



76 USING CHARACTER SETS 



IN-USE TABLE 



MAPPING FUNCTIONS 

(7) LSO(SI) 

@ LS1 (SO) 

© LS2 (SS2) 

(4) LS1R 

(D LS3 (SS3) 

(6) LS2R 

(7) LS3R 



DESIGNATING FUNCTIONS (SCS) 
(a) ESC ( FINAL (94-CHAR SET) 
(£) ESC) FINAL (94-CHAR SET) 

ESC - FINAL (96-CHAR SET) 
(c) ESC * FINAL (94-CHAR SET) 

ESC . FINAL (96-CHAR SET) 
(5) ESC + FINAL (94-CHAR SET) 

ESC / FINAL (96-CHAR SET 




VT300 CHARACTER SETS 



ASCI 

DECSUPPLEMENTA 
ISOSUPPLEMENTA 
NRCSETS 



*L \ US 

L JsL 



SER PREFERRED 
SUPPLEMENTAL 

DEC SPECIAL GRAPHIC f^ 300 M0DE 0NLY) 
DEC TECHNICAL 
DOWN- LINE-LOADABLE 



MA-0072-86 



Figure 5-3 Designating and Mapping Character Sets in VT300 Mode 



USING CHARACTER SETS 77 



Locking Shifts - When you use a locking shift, the character set remains in 
GL or GR until you use another locking shift. Table 5-3 lists all locking shifts 
available. 

Table 5-3 Mapping Character Sets with Locking Shifts 



Locking Shift 


Code 


Function 


LSO (locking shift 0( 


SI 

0/15 


Map GO into GL. (default) 


LSI (locking shift 1) 


SO 

0/14 


MapGl intoGL. 



NOTE: The following locking shift functions are available only in 
VT300modc. M'i;^ " \'l 



LS1R (locking shift 1, 


right! ■ 


ESC 

1/11 7/14 


MapGl intoGR. 


LS2 (locking shift 2) 




ESCn 

1/11 6/14 


Map G2 into GL, 


LS2R (locking shift 2. 


right) 


ESC ! 

1/11 7/13 


Map G2 into GR. 


LS3 (locking shift 3) 




ESC o 
1/11 6/15 


MapG3 intoGL. 


LS3R (locking shift 3, 


right) 


ESC | 
1/11 7/12 


Map G3 into GR. 



Examples 



The following sequence designates the DEC Technical character set 
as Gl, then maps Gl into GL. 

ESC ) > SO 

designate as Gl map Gl into GL 

The following sequences designate the ISO Latin-1 supplemental 
character set as G2, then map G2 into GR. 

ESC . A ESC } 

designate as G2 map G2 into GR 



78 USING CHARACTER SETS 



Single Shifts - You use a single shift when you want to display the next char- 
acter from a different character set. A single shift maps the G2 or G3 set into 
GL. The character set is active for only one character. Then the terminal re- 
turns to the previous character set in GL. 

The terminal has two single-shift control functions available. 



Single-Shift 


8-Bit 


7-Bit Equivalent 




Control 


Character 


Sequence 


Function 


Single shift 2 


SS2 


ESC N 


Maps G2 into GL 




8/14 


1/11 4/14 


for the next 
character. 


Single shift 3 


SS3 


ESC O 


Maps G3 into GL 




8/15 


1/11 4/15 


for the next 
character. 



Example 

Suppose the ASCII character set is in GL. You want to display the alpha char- 
acter from the DEC Technical character set, already designated as G3. You do 
not want to replace the ASCII set just to display one character. Instead, you 
can use single shift 3 to temporarily map the DEC Technical set (G3) into GL. 



SS3 

8/15 

single 
shift 3 



a 

6/1 

alpha 
character 



After displaying the alpha character, the terminal maps the ASCII set (Gl) 
back into GL, replacing the DEC Technical set (G3). 

National Replacement Character Sets 

The terminal has twelve 7-bit character sets for different national languages 
(Chapter 2). Only one national replacement character set is available at a time. 

To use a national replacement character set, you must select national replace- 
ment character set mode. When you reset this mode, the terminal uses 7-bit 
and 8-bit characters from one of the multinational character sets (DEC 
Multinational or ISO Latin-1). When you set this mode, the terminal uses 7-bit 
characters from an NRC set. 

See "National Replacement Character Set Mode" at the end of Chapter 4. 



USING CHARACTER SETS 79 



Preferred Supplemental Character Sets 

You can assign the supplemental character set you use most often as a special 
standby set. This standby set is called the user-preferred supplemental set. 
This feature provides applications with an easy way to access the user's pre- 
ferred supplemental set. 

You can assign the DEC Supplemental Graphic or ISO Latin-1 supplemental 
set as the standby set. After you assign a set, you must designate and map the 
set before using it. 

1. Designate the set as Gl, G2, or G3. 

2. Map the set into GR. 

For more information on designating and mapping sets, see "Selecting 
Character Sets" in this chapter. 

You can assign a supplemental character set as follows. 

Assign User-Preferred Supplemental Set (DECAUPSS) 

Default: DEC Supplemental Graphic 

Sequence Function 



DCS ! u % 5 ST 

9/0 3/0 2/1 7/5 2/5 3/5 9/12 



DCS 1 



ST 



9/0 3/1 2/1 7/5 4/1 9/12 



Assigns the DEC Supplemental 
Graphic set as the preferred 
supplemental set. 

Assigns the ISO Latin-1 
supplemental set as the 
preferred supplemental set. 



ANSI Conformance Levels 

This control function lets an application map certain character sets into the 
terminal's in-use table as default sets. The character sets are based on ANSI 
conformance levels, listed below. These conformance levels are from the dpANS 
X3. 134.1 standard. 

ANSI conformance levels represent an agreement between the sender and re- 
ceiver for compatible data exchange. The control function acts as an announcer 
for the data exchange that follows between the terminal and application soft- 
ware. The control function selects which character sets the terminal uses by 
default in the data exchange. 



80 USING CHARACTER SETS 



The VT300 supports three ANSI conformance levels. 

ANSI Levels 1 and 2 

• ASCII designated as GO. 

• ISO Latin-1 supplemental designated as Gl. 

• GO mapped into GL. 

• Gl mapped into GR. 

ANSI Level 3 

• ASCII designated as GO. 

• GO mapped into GL. 

The announcer function is as follows. 

ESC sp Final 

1/11 2/0 4/? 



where 



Final indicates the ANSI conformance level for the following data 
exchange. 



Final 


ANSIC 


L 


Level 1 


M 


Level 2 


N 


Level 3 



Notes 



If the terminal is reset, turned off, or changed with a set confor- 
mance level (DECSCL) sequence, software must send another an- 
nouncer sequence to the terminal. Otherwise, the terminal uses the 
default character sets (ASCII in GL, DEC or ISO Latin-1 supple- 
mental in GR). 

The announcer sequence is available in VT300 mode only. 

Do not confuse ANSI conformance levels with Digital conformance 
levels (Chapter 4). 



USING CHARACTER SETS 81 



SOFT CHARACTER SETS 

You can down-line-load a soft character set from the host computer into the 
terminal. This feature lets you design your own soft character sets for use with 
the terminal. You can only load soft character sets in VT300 mode. 

NOTE: VT200 fonts may appear different on a VT300 terminal, because VT300 
character cell sizes are different from those of the VT200. See the Pcmw param- 
eter in Table 5-6. 

The soft character set is also known as a dynamically redefinable character set 
(DECS). The terminal stores the soft characters in its DRCS buffer. 

NOTE: The terminal does not store the soft character set in nonvolatile RAM. 
When you turn off the terminal, the soft characters are lost. 

The next section describes the guidelines for designing a soft set. The sections 
that follow describe how to code, load, designate, and clear a soft set. 

Designing a Soft Character Set 

Your terminal displays each character by turning on a series of pixels. A pixel 
(picture element) is the smallest displayable unit on the screen. Each character 
must fit in a limited area, called the character cell. The VT300 uses a default 
character cell size of 10 x 20 pixels. 

When you design a character, you should lay out a character cell on grid paper. 
The little boxes on the grid paper represent pixels. You fill in the pixels that 
make up the character. The next section shows an example of a character 
design. 

You can design characters for an 80-column or 132-column font. The largest 
character cell you can use is the default size of 10 x 20 pixels (200 pixels) for 
an 80-column font. Figure 5-4 shows the cell sizes for 80- and 132-column 
fonts. The built-in fonts supplied by Digital follow the guidelines in Table 5-4. 

You must design your characters to fit the cell. The terminal ignores any pixels 
that are defined outside the cell. 

Figure 5-5 shows an example of this spacing for an uppercase D character. In 
this example, the character for the 80-column font has two pixel columns re- 
served for spacing. 



82 USING CHARACTER SETS 



80-COLUMN FONT 
10 PIXELS 



132-COLUMN FONT 



1 


S 

1 






































































































































































































20 PIXEL 



















































































































































































































































1 


• 6PIXELE 






i 


i 
LS 






























































































































20PIXE 



























































































































































Figure 5-4 Character Cell Sizes for 80- and 132-Column Fonts 



Table 5-4 Guidelines for Designing Soft Characters 



Character Dimension 



80-Column Font 132-Column Font 



Cell width 
Cell height 


10 
20 


pixels 


6 
20 


pixels 


Body width 
Body height 


9 

12 




5 

12 




Ascender height .■'."• 
Descender height 


4 
4 




4 

4. 




Spacing before character 
Spacing after character 




1 






1 





USING CHARACTER SETS 83 



80-COLUMN FONT 



132-COLUMN FONT 



CHARACTER 

BODY WIDTH SPACING 



WIDTH SPACING 
5 




CHARACTER 
BODY 
HEIGHT 12 



MA-0074-86 



Figure 5-5 Character Body Sizes for 80- and 132-Column Fonts 



Coding the Soft Character Set 

After you design your characters, you must code them for the terminal. This 
section describes how to code soft characters. The next section describes how 
to load the character codes into the terminal. 

Each pixel of a soft character cell receives a binary value of or 1. A 1 bit 
indicates the pixel is on, and a bit indicates the pixel is off. 

The terminal receives the code for a soft character in sections, called sixels. A 
sixel is a 6-bit binary code that represents a vertical column of 6 pixels on the 
screen. Each bit in a sixel corresponds to a pixel on the screen. The following 
example describes how to design and code a soft character. 



84 USING CHARACTER SETS 



Example 

Suppose you want to design an uppercase D for an 80-column font. 

1. Draw your design on a grid. 

Use the grid for an 80-column character cell to draw your design. 
Mark which pixels will be on and which pixels will be off. Your de- 
sign may look like Figure 5-5. 

2. Divide the character cell into columns of 6 bits each. 

Use the format shown in Figure 5-6. Each 6-bit pattern represents 6 
pixels, or a sixel. The least significant bit is at the top, and the 
most significant bit is at the bottom. The terminal would receive the 
sixel columns in order (1 to 10), starting with Group A. 

12 3456789 10 




MA-0075-SS 



Figure 5-6 Example of an Uppercase D 
in an 80-Column Font 



USING CHARACTER SETS 85 



Because the character cell height (20 pixels) is not a multiple of 6, 
the columns on the bottom of the character cell (Group D) have only 
2 bits each, bO and bl. Bits b2 through b5 in the bottom cell do not 
affect the character's appearance, so they have been excluded from 
Figure 5-6. 

3. Convert the binary value of each sixel to its hexadecimal value. 

Sixels codes are restricted to characters in the range of ? (hex 3F) 
to ~ (hex 7E), so you must add an offset of hex 3F to the hex value 
of each column. For example, 



000000(2) = 00(16) 
+ 3F(16) 



110101 = 35(16) 
+ 3F(16) 



111111(2)= 3F(16) 
+ 3F(16) 



3F(16) 



74(16) 



7E(16) 



4. Use Table 5-5 to convert each binary number to the equivalent 
ASCII character. 

Table 5-5 lists the results of steps 3 and 4 for each possible binary 
value. All you have to do is find the 6-digit binary number for each 
sixel bit pattern in your character design. 

Figure 5-7 shows this conversion for the uppercase D in this 
example. 

You use this procedure to convert each character of your soft character set into 
a string of sixel bit patterns. Then you can down-line-load your DRCS charac- 
ters into the terminal, using the DECDLD device control string described in 
the next section. 



86 USING CHARACTER SETS 



Table 5-5 


Converting 


Binary Code 


to an ASCII C 


Binary 


Hex 


Hex Value 


Character 


Value 


Value 


+ 3F Offset 


Equivalent 


000000 


00 


3F 


? 


00000 I 


01 


40 


@ 


000010 


02 


41 


A 


000011 


03 


42 


B 


000100 


04 


43 


• C " • ' 


000101 


05 


44 


D 


000110 


06 


45 


E 


000111 


07 


46 


F 


001000 


08 


47 


G 


001001 


09 


48 


H 


001010 


A 


49 


I 


001011 


B 


4A 


J 


001100 


C 


4B 


K 


001101 


D 


4C 


L 


001110 


E 


4D 


M 


001111 


F •■ ■ 


4G 


N 


010000 


10 


4F ' .. 


O 


010001 


11 


50 


P 


010010 


12 


51 


Q 


010011 


13 


52 


R 


010100 


14 


53 


S 


010101 


15 


54 


T ■ 


010110 


16 


55 


U 


010111 


17 


' 56 


V 


011000 


18 


57 


W 


011001 


19 


58 


X 


011010 


1A 


59 


Y 


011011 


IB 


5A 


z 


1 1 100 


1C 


5B 


[ 


011101 


ID 


5C 


: V 



USING CHARACTER SETS 87 



Table 5-5 


Converting Binary Code 


to an ASCII ( 


Binary 


Hex 


Hex Value 


Chin-jinn- 


Value 


Value 


+ 3F Offset 


Equivalent 


011110 


IE 


51) 


■]■'■■-'■■' 


Oil ill 


IF 


5E 


- . {■■■ 


100000 


20 


SI'" 




100001 


21 


60 


i 


100010 


22 


61 


a 


10001 1 


23 


62 


■ b . 


100100 


24 


63 


: ;?:$$-M'MM\ : :i 


100101 


25 


6-1 


(1 


100110 


26 


65 





100111 


27 


66 


W&MBM 


101000 


28 


m 


g 


101001 


29 


08 


h 


101010 


2A 


69 


3^;M : fffiS^ 


101011 


2B 


6A 


:"j' ;: ..'-.-::-.'.'-:-"- : : 


10 J too 


2C 


(JB 


u 


101101 


2D 


ec 


!■■■■■'■' 


101110 


2E 


6D 


'. m ■ 


101111 


" 2F " : 


6E 


n 


110000 


30 


6F 





110001 


31 


70 


P 


110010 


32 


71 


q -^ . ■ 


11001 1 


' 33 


72 


kMWW':WW: 


100100 


34 . 


73 


s 


110101 


35 


■ 74 


■•. t;. ' . 


110110 


36 


75 


'■ u 


110111 


37 


76 


■'■/ -*-'.-lV: : ■ 


111000 


38 


77 


w 


111001 


39 


78 


' \ .'■ ' 


111010 


3A 


70 


y 


1111)11 


3B 


7A 


Si^S^^^^HW 


111100 


3C 


7B 


; -:-;VJf : l ; :::': 


111101 


3D 


70 


llfill 


111110 ■ 


3E 


7D 


* 

:- : .'i.': : '. 


mill ' 


3F ■ 


7E 


- 



88 USING CHARACTER SETS 



10 



iflflfl 



GROUP A 



110000 01000 SAME SAME 100000 000000 SAME SAME SAME SAME 

>■ T > - — »— ' AS AS ' 1 ' k < ' AS AS AS AS 

0022 - ? 6 6 6 6 

(6/15) (4/15| (5/15) (3/15) 




9 10 



111111 000000 SAME SAME SAME 000001 000010 111100 000000 SAME 

~ ? 2 2 2 @ A I ?9 



(7/14) (3/15) 



(4/0) (4/1) (7/11) (3/15) 

6 7 8 9 10 



B 



001111 001000 SAME SAME 000100 000010 000001 000000 SAME SAME 

• , ■ • , ■ AS AS • y — ' ' . ■ ' • ' ' ' ' AS AS 

N G 2 2 CA@ ? 88 

(4/14) j/7) (4/3) (4/1) (4/0) (3/15) 

NOTE: 

FOR THIS EXAMPLE. THE BITS IN GROUP D DO NOT AFFECT 

THE APPEARANCE OF THE CHARACTER. 

Figure 5-7 Sixel-to-ASCII Conversion 



GROUP B 



GROUP C 



MA-0076-86 



USING CHARACTER SETS 89 



Down-Line-Loading Soft Characters 

You can load two font renditions of your soft character set. 

80-column 
132-column 

You should load both an 80-column and a 132-column rendition of your soft set. 
Then the terminal can select the correct rendition if you change the page width 
(Chapter 6). 

If you only load a normal or bold rendition of the soft set, the terminal uses 
the rendition that is currently available. 

Do not confuse the font rendition with the actual character set. You cannot 
load two different soft sets. However, you can load two renditions of the same 
soft set. 

You load your soft character set with a DECDLD device control string. This 
control string has the following format. 

NOTE: See Chapter 2 for general information about device control strings. 

DCS Pfn ; Pen ; Pe ; Pcmw ; Pw ; Pt ; Pcmh ; Pcss { 
Dscs Sxbpl ; Sxbp2 ;...; Sxbpn ST 

where 

DCS (9/0) 

is the device control string introducer. DCS is an 8-bit CI character. 
You can use the equivalent 7-bit sequence ESC P (1/11, 5/0) when 
coding for a 7-bit environment. 

Pfn ; Pen ; Pe ; Pcmw ; Pw ; Pt ; Pcmh ; Pcss 

are parameter characters, separated by semicolons (3/11). Table 5-6 
describes these parameters and lists their possible values. Table 5-7 
describes the combinations of Pcmw, Pt, and Pcmh you can use for 
80- and 132-column fonts. If you use any other combinations, the 
terminal ignores the DECDLD string. 



90 USING CHARACTER SETS 



{ (7/11) 

is the final character. It marks the end of the parameter characters 
and indicates that this string is a DECDLD function. 



Dscs 



defines the name for the soft character set. You use this name in 
the select character set (SCS) escape sequence. You use the follow- 
ing format for the Dscs name. 

IF 

where 

I 

is 0, 1 or 2 intermediate characters from the range 2/0 to 2/15 
in the ASCII character set. 

F 

is a final character in the range 3/0 to 7/14. 

Examples of Dscs Names 

Name Function 

sp @ Defines the character set as an 

2/0 4/0 unregistered soft set. This value is the recom- 

mended default for user-defined sets. The value of 
Pcss defines whether this set has 94 or 96 
characters. 

A If Pcss is 0, A defines the soft 

4/2 character set as the U.K. national replacement 

character set. 

If Pcss is 1, A defines the soft character set as 
the ISO Latin-1 supplemental set. 

& % C Defines the soft character set as % C, 

2/6 2/5 4/3 which is currently an unregistered set. The value 

of Pcss defines whether this set has 94 or 96 

characters. 



USING CHARACTER SETS 91 



Sxbpl ; Sxbp2 ;...; Sxbpn 

are the sixel bit patterns for individual characters, separated by se- 
micolons (3/11). Your character set can have 1 to 94 patterns or 1 to 
96 patterns, depending on the setting of the character set size pa- 
rameter (Pcss). Each sixel bit pattern is in the following format. 

S...S/S...S 

where 

the first S...S 

represents the sixels in Group A of the soft character (Figure 
5-6) 

/ (2/5) 

advances the sixel pattern to Group B of the soft character 

the second S....S 

represents the sixels in Group B of the soft character. 

ST (9/12) 

is the string terminator. ST is an 8-bit CI character. You can use 
the equivalent 7-bit sequence ESC \ (1/11, 5/12) when coding for a 
7-bit environment. 

After you load your soft character set, you must designate the set as GO, Gl, 
G2, or G3. 

Table 5-6 : c;\. DECDLD Parameter Characters 

Parameter Name Description 

Pfn Font Selects the DRCS font buffer to load. 

number The VT300 lias two DRCS font buffers. One font 

buffer h dedicated to session 1, the other to ses- 
-'. : .;V'.' ; ;V ; : sion 2. Kaeh font buffer is called DECS buffer 1. '"■ 

"■":':': \ . ■ , Pfn has two valid values, and 1 . Both values 

/: : v.-:;V : : : ; o. ; ^■■v> r ;.■■■ ;.;.': ; .>'..v : : refer to DRCS buffer ! for each session. 



92 USING CHARACTER SETS 



Table 5-6 DECDLD Parameter Characters (Cont) 



PanmiH.pr 
Pen 



Name 

Starting 
character 



i . 



Erase 
control 



Description 

Selects where to load ! he first character 
in the DRCS font buffer. The location corre- 
sponds to a location in the ASCII code table 
(Table 2-11. For example, a Pen value of means 
that the first soft character is loaded into posi- 
tion 2/0 of the character table. A Pen value of 1 
means position 2/1 in the table, and so on up to 
Pen = 95 (position 7/15). 

Pen ifr affected by the character set size. See 

Pcss below. 

Selects which characters to erase from 

the DRCS buffer before loading the new font. 



Pcmw 



Character 

matrix 

width 



= erase all characters in the DRCS buffer with 

this number, width and rendition. 

1 = erase only characters in locations being 

reloaded. 

2 — erase all renditions of the soft character set 

(80-column and 132-e.olumnl. 

Selects tno n^nrJnimiivhe.rutej ftli width. 

VTSOOmode 

= 10 pixels wide for 80 columi s, 

6 pixels wide for 132 columns, 
(default) 

1 = illegal 

2 = 5 x 10 pixel cell (VT200 compatible). 

3 = «xl() pixel cell (VT200 compatible). 

4 = 7x10 pixel cell (VT200 compatible). 

5 = 5 pixels -.ide. 

6 = 6 pixels wide. 



10 = 10 pixels wide. 



USING CHARACTER SETS 93 



Table 5-G DECDLD Parameter Characters (Coat) 



Parameter Name 
Pcmw (cont) 



Pw 



Font 
Width 



Description 

If you omit a Pcmw value, the terminal uses the 
default character width. If the Pe parameter is 0. 
Pcmw must be less than 10. Any Pcmw value 
over 10 is illegal. 

For VT200 compatible software: Use a Pcmw 
value of 2. 3. or 4. When you use these values. 
the VT300 doubles the height of the font defini- 
tions in memory. This makes the soft set the 
same height as the hard sets. If you use a Pcmw 
value of 0, the VT300 does not double the height 
and the soft set appears smaller than the hard 
sets. Remember that the VT200 fonts may appear 
different on the VT300. ■ : ' 

For fonts designed far the VT300: Use values 5 
through 10. ■ ' 

For compatibility between VT200 and VT300 ter- 
minals: Use a Pcmw value of 5. fi, or 7. 

Selects the number of columns per line 
(font set size). 

— 8(1 columns, (default} 

1 — 80 columns. 

2 = 132 columns. 



94 USING CHARACTER SETS 



Table 5-6 DECDLD Parameter Characters (Cont) 



Parameter 


Name 


:: ^::^y: ;: -: Description 


Pt 


Text or 


Defines the font as a text font or 




full-cell 


■•' full-cell font. ' ; . .■ ' • 
= text, (default) 

■ 1 = tCXt. : : 

2 = full cell '■ ■ 



Pcmh 



Character 

matrix 

height 



Full-cell fonts can individually address all pixels 
in a cell. 

Text fonts cannot individually address all pixels. 
If you specify a text cell, the terminal automati- 
cally performs spacing and centering of the 
characters. 

Selects the maximum character cell 
height. ■';■ '■■;"■':. vv -'; : ' : ;. : -.-;'- ',■■;.; ■; ':.:■; - '<*;. ...-/.: :U : 

or omitted = 20 pixels high, (default) 

1 — ] pixel high. 

2 = 2 pixels high. ^^2^M^rX : 

3 : .:== 3 pixels high. 



'•'■'■' ■ ■ .■'.. 20 = 20 pixels high. ■■ • ■ ■•'■.'.■■ 

: . ; ;;';-;. ■' ; : ; , : .;C ;, K ■; ; Pcmh values over 20 are illegal. If the value of 

. ■ •■. '.•■.■ Pcmw is 2, 3, or 4, Pcmh is ignored. 

Pcss Character Defines the character set as a 94- or 

set size 96-character graphic set. 

= 94-charactcr set. (default) 

..-.■'■ ' •. . ■ . 1 = 96-character set. .' ■..'.■■'.''' . 

The value of Pcss changes the meaning of the Pen (starting character) param- 
eter above. 



USING CHARACTER SETS 95 



■ • Table 5-6 DECDLD Parameter Characters (Cant) 
Parameter Name . ■ 'Description 

Examples 

' • If Pcss = (94-character set) ■ ' ' . 

The terminal ignores any attempt to load characters into the 2/0 or 
7/ 15 tabic positions. 

Pen Specifics ' 

1 column 2/row 1 

column 14 

;\ • If Pcss - 1 (96-clmractcr set) ■'.'."' : 

Pen Specifies 

column 2/row 

95 column 7 /row 15 

Table 5-7 Valid DEC!>LB P&mneter Combmutlous 



Pcimv Pt 


Pcmh 


Pw 


80-Column Fonts 






2 to 9 0. 1 
2 to 10 2 


1 to 20 
1 to 20 


0. 1 

0. 1 


132-Column Fonts 






2 to 5 0, 1 
2 to 6 2 


1 to 20 
1 to 20 


2 

2 



96 USING CHARACTER SETS 



Designating the Soft Character Set 

You designate your soft character set the same way you designate the hard 
character sets — using a select character set (SCS) sequence. You also use the 
same format for the SCS sequence. 

ESC Intermediate(s) Final 

1/11 ********* ***** 

where 



Intermediate(s) 

are zero or more characters that designate the soft character set as 
one of the logical sets, GO through G3. You use the same intermedi- 
ate characters that you use for hard character sets (Table 5-2). 

An intermediate character also indicates that the soft character set 
is a 94- or 96-character set. Make sure you use an intermediate 
character that matches the setting of the character set size param- 
eter (Pcss) in the DECDLD string (Table 5-6). 

Final 

is the Dcsc name you used for the soft character set in the 
DECDLD string. 

Notes on Designating Soft Character Sets 

• Replacing a soft set with a new soft set 

If you use a new Dscs name when you replace the current soft set 
with another soft set, then the following occurs. 

— Characters from the old soft set are undefined. If you redefine 
the soft set, characters currently on the screen may change. 

— Any logical sets (GO, Gl, G2, G3) used to designate the old soft 
set are undefined. The in-use table is also undefined. 

After you load a new soft set, use a select character set (SCS) se- 
quence to designate the soft set. Using SCS eliminates the confu- 
sion involved with undefined characters. 



USING CHARACTER SETS 97 



• Replacing a hard set with a soft set 

You can define a soft set that replaces one of the hard sets (such as 
ASCII or DEC Special Graphic). 

A soft set that replaces a hard set remains in effect until you per- 
form one of the following actions. 

— Clear the soft set (using the Recall Saved Settings or Recall 
Factory Default Settings set-up features, or the power-up self- 
test). 

— Redefine the soft set (using another DECDLD string). 

Soft Character Set Example 

Suppose you want to create a soft character set containing a solid rectangle, a 
blank, a rectangular box, and a striped rectangle. This example shows how you 
would 

• down-line-load the set, 

• designate the set as Gl, and 

• map the Gl set into GL. 

NOTE: Make sure the terminal is in VT300 mode before you try to load a soft 
character set. You cannot load soft sets in VT100 mode. 

1. You could use the following DECDLD string to load your character 
set. (The string is shown divided into sections for clarity.) 

DCS 

1 ; 1 ; ; 8 ; 1 ; 1 ; 20; { sp 3 
/ / / 

????????/????????/????????/???????? 

~aaaaaa~ /"??????"/"??????" /"aaaaaa" 

TTTTTTTT/TTTTTTTT/TTTTTTTT/TTTTTTTT 
ST 

98 USING CHARACTER SETS 



where 



DCS (9/0) 

introduces the device control string. 

1;1;0;8;1;1;20;0 

is the parameter string specifying the following. (See Table 5-6 
for parameter definitions.) 



Parameter 
Pfn= 1 
Pcn= 1 

Pe = 



Pcmw = 


= 8 


Pw= 1 




Pt = 1 




Pcmh = 


20 


Pcss = 






Function 

Loads this soft set into the DRCS font buffer. 

Selects the character at row 2/ column 1 in the 
ASCII table (Chapter 2) as the first character 
to load. 

Erases all characters in the font buffer for that 
rendition. 

Selects a maximum character width of 8 
pixels. 

Selects a font width of 80 columns. 

Defines the set as a text font. 

Selects a maximum character height of 20 
pixels. 

Defines the set as a 94-character set. 



{ (7/11) 

indicates the end of the parameter characters and specifies that 
this sequence is a DECDLD string. 

sp @ (2/0, 4/0) 

defines the character set as an unregistered soft set. This value 
is the recommended default value for user-defined sets. The sp 
represents one space. You can use other values to define other 
specific character sets. 



-/- 



-/- 



-/- 



-/ 



represents the first character (a solid rectangle). 



USING CHARACTER SETS 99 



; (3/ii) 

separates the soft characters. 

????????/????????/????????/???????? 

represents the second character (a blank). 

~@@@@@ @T?????rr??????TAAAAAA" 

represents the third character (a hollow rectangle). 

represents the fourth character (a set of horizontal stripes). 

ST (9/12) 

indicates the end of the DECDLD string. 

2. Now you are ready to designate the character set as Gl. You can 
use the following SCS escape sequence. 



ESC ) sp 



where 



ESC (1/11) 

introduces the SCS sequence. 

) (2/9) 

designates the character set as Gl. 

sp @ (2/0, 4/0) 

selects the soft set as the set to designate as Gl. Remember, 
sp @ was the name used for the soft set in the DECDLD 
string. 

Finally, you want to map the Gl set into the in-use table as GL. 
You can map the set by sending a shift out (SO) control character. 
To send the SO character, you hold down the Ctrl key and press N 
key. 

NOTE: For information on using shift characters, see Chapter 3. 
For information on mapping sets, see "Mapping Character Sets" in 
this chapter. 

The soft character set should now be loaded and ready for use. 



100 USING CHARACTER SETS 



Clearing a Soft Character Set 

You can clear a soft character set that you loaded into the terminal by using 
the following DECDLD control string. 

DCS 1;1;2 { sp @ ST 
Any of the following actions also clear the soft character set. 

• Performing the power-up self-test. 

• Selecting the Recall Saved Settings or Recall Factory Default 
Settings set-up features. 

• Using a reset to initial state (RIS) sequence. 



USING CHARACTER SETS 101 



6 



PAGE MEMORY 



What is Page Memory?, 103 

Page Memory for a Single Session, 104 

Page Memory for Dual Sessions, 105 
Controlling the Page Format, 106 

Selecting 80 or 132 Columns per Page, 106 
Set Columns per Page (DECSCPP), 106 
Column Mode (DECCOLM), 106 

Set Lines per Page (DECSLPP), 107 

Origin Mode (DECOM), 108 

Set Top and Bottom Margins (DECSTBM), 108 
Moving to Another Page, 109 

Next Page (NP), 109 

Preceding Page (PP), 109 

Page Position Absolute (PPA), 110 

Page Position Backward (PPB), 110 

Page Position Relative (PPR|, 111 
Summary, 111 



This chapter describes the control functions that affect the terminal's page 
memory. The chapter covers the following topics. 

• What is page memory? 

• Controlling page format 

• Moving through pages 

This chapter assumes you are familiar with the character-encoding concepts de- 
scribed in Chapter 2. 



102 



WHAT IS PAGE MEMORY? 

Many terminals only have enough memory to store the data that appears on 
their screen. The VT300 has memory to store more data than you can display 
on the screen. The size of this memory is equal to 144 lines by 80 or 132 
columns. You can divide this memory into one or more pages. 

Page memory lets you store more text locally in the terminal. The screen can 
display up to 24 lines from page memory at a time. You can use control func- 
tions (such as scrolling and panning) to display the other lines. 

Page memory can provide a faster response time. While the terminal displays 
one page, the host can write to another (Chapter 10). 

You divide page memory into a number of equal-sized pages, by selecting one 
of several standard page sizes. A page in page memory is similar to a page in a 
book. Each page has left, right, top, and bottom margins. You can define the 
position of the top and bottom margins on a page. The left and right margins 
are always set according to the current page width. You select the page format 
by using control functions or set-up. This chapter describes the control 
functions. 

Applications can write to page memory by first addressing a page, then writing 
data to the page. If the application wants write to another page, the application 
must address that page. 

Figure 6-1 shows the basic parts of a page. The figure shows the default page 
size of 24 lines x 80 columns. Your terminal screen can display 24 lines at a 
time. However, you can make the length of a page larger than the screen. 



TOP MARGIN 



LEFT 
MARGIN 



RIGHT 
MARGIN 



80 COLUMNS 



24 
LINES 



BOTTOM MARGIN 



MA-0079-86 



Figure 6-1 A Page in Page Memory 



PAGE MEMORY 103 



Page Memory for a Single Session 

When you use a single session, the full 144 lines of page memory are available. 
See Chapter 14 for details on session management. 

You can select one of the following page sizes for a single session. Figure 6-2 
shows these page sizes. 



6 pages of 24 lines x 80 or 132 columns 
4 pages of 36 lines x 80 or 132 columns 
2 pages of 72 lines x 80 or 132 columns 
1 page of 144 lines x 80 or 132 columns 



1PAGE 



80/132 
•COLUMNS- 



24 
LINES 



J 



80/1 32 
-COLUMNS- 



36 

LINES 
J 



80/132 
-COLUMNS- 



72 
LINES 



80/1 32 
-COLUMNS- 



144 
LINES 



MA-0089-86 



Figure 6-2 Page Sizes for a Single Session 



104 PAGE MEMORY 



Page Memory for Dual Sessions 

When you use dual sessions, each session has 72 lines of page memory avail- 
able. See Chapter 14 for details on session management. 

You can select one of the following page sizes for dual sessions. Figure 6-3 
shows these page sizes. 

• 3 pages of 24 lines x 80 or 132 columns 

• 2 pages of 36 lines x 80 or 132 columns 

• 1 page of 72 lines x 80 or 132 columns 



2 PAGES 



80/1 32 
-COLUMNS- 



24 
LINES 

_L_ 



80/1 32 
•COLUMNS- 



36 
LINES 



80/132 
-COLUMNS - 



72 
LINES 



MA-0078-86 



Figure 6-3 Page Sizes for Dual Sessions 



PAGE MEMORY 105 



CONTROLLING THE PAGE FORMAT 



This section describes how to select the page size, and top and bottom margins 
for page memory. You use the same basic control functions for single or dual 
sessions. 

Selecting 80 or 132 Columns per Page 

There are two control functions that can set the page width to 80 or 132 col- 
umns, DECSCPP and DECCOLM. 

PROGRAMMING TIP: Digital recommends that new applications use 
DECSCPP rather than DECCOLM. DECSCPP does not clear page memory or 
reset the scrolling regions, as does DECCOLM. DECCOLM is provided mainly 
for compatibility with previous products. 

Set Columns per Page (DECSCPP) 

Default: 80 columns 

Sequence 

CSI $ | 
9/11 2/4 7/12 



CSI $ I 

9/11 3/0 2/4 7/12 

CSI 8 $ | 

9/11 3/8 3/0 2/4 7/12 

CSI 1 3 2 $ | 

9/11 3/1 3/3 3/2 2/4 7/12 



Action 

Sets each page to 80 columns. 

Sets each page to 80 columns. 

Sets each page to 80 columns. 

Sets each page to 132 columns. 



Notes on DECSCPP 



If you switch from 132-column to 80-column pages, you can lose 
data from page memory. Columns no longer present in page mem- 
ory are lost. Make sure you set page columns before you enter data 
into page memory. 



Column Mode (DECCOLM) 

Default: 80 columns 

Mode Sequence 

Set CSI ? 3 h 



(132) 



9/11 3/15 3/3 6/8 



Action 

Selects the 132-column font 
to display text on the screen. 



106 PAGE MEMORY 



Reset CSI ? 3 1 

(80) 9/11 3/15 3/3 6/12 



Selects the 80-column font 
to display text on the screen. 



Notes on DECCOLM 

• If you change the DECCOLM setting, the terminal 

— sets the top and bottom scrolling margins to their default posi- 
tions, and sets all pages to have 24 lines 

— erases all data in page memory. 

• DECCOLM does not clear data from the status line. 

Set Lines per Page (DECSLPP) 

This control function sets the number of lines for each page in page memory. 
The number of lines you can select depends on whether you use a single ses- 
sion or dual sessions. 

Default: 3 pages of 24 lines 









Page Length 




Sequence 


Dual Session 


Single Session 


CSI 2 

9/11 3/2 


4 

3/4 


t 

7/4 


3 pages of 
24 lines 


6 pages of 
24 lines 


CSI 3 

9/11 3/3 


6 

3/6 


t 

7/4 


2 pages of 
36 lines 


4 pages of 
36 lines 


CSI 7 

9/11 3/7 


2 
3/2 


t 

7/4 


1 page of 
72 lines 


2 pages of 
72 lines 


CSI 1 


4 


4 t 


Not available 


1 page of 


9/11 3/1 


3/4 


3/4 7/4 




144 lines 



Notes on DECSLPP 



If you switch to a smaller page size, data that was on the larger 
page may be split across the smaller pages. To avoid confusion, 
make sure you set the lines per page before you enter data into 
page memory. 



PAGE MEMORY 107 



• DECSLPP usually does not change the top and bottom scrolling 
margins. However, if you change the page size, and the current 
scrolling margins exceed the new page size, the terminal resets the 
margins to the page limits. 

Origin Mode (DECOM) 

This control function allows cursor addressing relative to the top and bottom 
margins or the complete page. DECOM determines if the cursor position is 
restricted to inside the page margins. When you power up or reset the termi- 
nal, you reset origin mode. 

Default: Origin at upper-left of screen, independent of margins. 



Mode 

Set 

(Margin- 
dependent) 



Reset 
(Margin- 
independent) 



Sequence 

CSI ? 6 h 

9/11 3/15 3/6 6/8 



CSI ? 6 1 

9/11 3/15 3/6 6/12 



Action 

Sets the home cursor position 
at the upper-left corner of the 
screen, within the margins. The start- 
ing point for line numbers depends on 
the current top margin setting. The 
cursor cannot move outside of the 
margins. 

Sets the home cursor position 
at the upper-left corner of 
the screen. The starting point for line 
numbers is independent of the mar- 
gins. The cursor can move outside of 
the margins. 



Set Top and Bottom Margins (DECSTBM) 

This control function sets the top and bottom margins for the current page. 
You cannot perform scrolling outside the margins. 

Default: Margins at page limits. 



CSI 

9/11 



Pt 

3/? 



; Pb 

3/11 3/? 



r 

7/2 



where 



Pt is the line number for the top margin. 
Default: Pt = 1. 



108 PAGE MEMORY 



Pb is the line number for the bottom margin. 

Default: Pb = 24, 36, 48, or 72 (depending on the number of lines per 

page). 

Notes on DECSTBM 

• The value of Pt must be less than Pb. 

• The maximum size of the scrolling region is the page size. 

• DECSTBM moves the cursor to column 1, line 1 of the page. 

MOVING TO ANOTHER PAGE 

The following control functions let you move the cursor forward or backward to 
another page in page memory. You can move in sequence or randomly. 
Applications can use these control functions to select the page to write to. 

Next Page (NP) 

This control function moves the cursor forward to the home position on one of 
the following pages in page memory. If there is only one page, the terminal 
ignores NP. 

Default: Move to the next page. 

CSI Pn U 

9/11 3/? 5/5 

where 

Pn indicates how many pages to move the cursor forward. 
Default: Pn = 0. 

If Pn is or 1, then the cursor moves to the next page in page memory. 
If Pn tries to move the cursor past the last page in memory, then the 
cursor stops at the last page. 

Preceding Page (PP) 

This control function moves the cursor backward to the home position on one 
of the preceding pages in page memory. If there is only one page, the terminal 
ignores PP. 



PAGE MEMORY 109 



Default: Move to the preceding page. 

CSI Pn V 

9/11 3/? 5/6 

where 

Pn indicates how many pages to move the cursor backward. 
Default: Pn = 0. 

If Pn is or 1, the cursor moves to the preceding page. If Pn tries to 
move the cursor back farther than the first page in memory, the cursor 
stops at the first page. 

Page Position Absolute (PPA) 

This control function can move the cursor to the corresponding row and column 
on any page in page memory. You select the page by its number. If there is 
only one page, the terminal ignores PPA. 

Default: Move to the next page. 

CSI Pn sp P 

9/11 3/? 2/0 5/0 

Pn is the number of the page to move the cursor to. If Pn is greater than 
the number of the last page in memory, the cursor stops at the last page. 
If Pn is less than the number of the first page, the cursor stops at the 
first page. 

Page Position Backward (PPB) 

This control function moves the cursor backward to the corresponding row and 
column on one of the preceding pages in page memory. If there is only one 
page, the terminal ignores PPB. 

Default: Move backward one page. 

CSI Pn sp R 

9/11 3/? 2/0 5/2 

where 

Pn indicates the number of pages to move the cursor backward. If Pn tries 
to move the cursor back farther than the first page in memory, the cursor 
stops at the first page. 

110 PAGE MEMORY 



Page Position Relative (PPR) 

This control function moves the cursor forward to the corresponding row and 
column on one of the following pages in page memory. If there is only one 
page, the terminal ignores PPR. 

Default: Move to the next page. 

CSI Pn sp Q 

9/11 3/? 2/0 5/1 

where 

Pn indicates how many pages to move the cursor forward. If Pn tries to 
move the cursor beyond the last page in memory, the cursor stops at the 
last page. 

SUMMARY 

Tables 6-1 and 6-2 list the control functions described in this chapter. 



PAGE MEMORY 111 



Table 6-1 Page Format Sequences 



Name 

Set columns per 
page 

Column mode 



Set lines per 
page 



Origin mode 



Set top and 
bottom margins 

<D) = default. 



Mnemonic Sequence 

DKCSCPP CSIPnSi 

Pn columns (80 or 132). 

DECCOLM Sot: CSI ? 3 h 

■ . . ■. .' . . ■ .-. 132 columns. '. ■ \. ■ ' ■ •.• '■•. ' ■ . 

Reset: CSI ?31 

80 columns. ID) 

DECSLPP CSTPnt 

Pn lines por page. 

The number of pages depend on how many 

you use. 

Pn Dual Single 
24 3 pages pages 
.Ui :-! 

DECOM Set:CSI?6h 

Move within margins. 

Reset: CSI ? 6 I 

Move outside margins. |D) 

DECSTBM CSIPtjPbr 

Hr = top line. 

Pb = bottom line. 



112 PAGE MEMORY 



Table 6-2 Sequences for Moving Through Page Memory 


Name 


Mnemonic 


■ Sequence 


New Cursor Position* 


Next page 


NP 


CSI Pn LI 


Home. 


Preceding page 


PP 


CSI Pn V 


Home. 


Page position 
absolute 


PPA 


CSI Pn sp P 


Same as old page. 


Page position 
backward 


PPB 


CSI Pn sp R 


Same as old page. 


Page position 
relative 


PPR 


CSI Pn sp Q 


Same as old page. 



* Pn = the number of pages to move, except for PPA. 
For PPA. Pn = the actual page number. 



PAGE MEMORY 113 



7 



SETTING VISUAL CHARACTER 
AND LINE ATTRIBUTES 



Setting Visual Character Attributes, 114 
Select Graphic Rendition (SGR), 115 

Setting Line Attributes, 116 

Single-Width, Single Height Line (DECSWL), 116 
Double-Width, Single Height Line (DECDWL), 116 
Double-Width, Double Height Line (DECDHL), 116 

Summary, 117 



This chapter describes how to select visual attributes for display characters. 
Visual character attributes change the way characters appear on the screen, 
without changing the actual characters. For example, the bold character attri- 
bute makes a character appear heavier on the screen. You can also select the 
visual attributes for a complete display line on the screen. 

SETTING VISUAL CHARACTER ATTRIBUTES 

This section describes how to select, change, and reverse visual character attri- 
butes. You can set the following attributes. 

bold 

underline 

blink 

negative image (dark character on a light background) 

invisible 



114 



Select Graphic Rendition (SGR) 

This control function selects one or more character attributes at the same time. 

Default: Clear all attributes. 



CSI Ps 

9/11 3/? 



; Ps 

3/11 3/? 



m 

6/13 



where 



Ps is a number representing a certain visual attribute. You can use more 
than one Ps value to select different character attributes. Table 7-1 lists 
Ps values and the attributes they select. 

Default: Ps = (clears all attributes). 



Table 7-1 

Ps 



1 

4 

5 

7 

8 ' ' 

22 

24 

25 

27 

28 

Examples 



Visual Character Attribute Values 



Attribute 

All attributes off 
Bold 

Underline 
Blinking 
Negative image 

Invisible 
Bold off 
Underline off 
Blinking off 
Negative image off 
Invisible off 



Mndu 



VTlOOor VT300 



VT30G only 



When you select more than one attribute in an SGR sequence, they 
are executed in order. For example, you can use the following se- 
quence to display text that is bold, blinking, and underlined. 

CSI ; 1 ; 5 ; 4 m 

The following sequence displays the negative image of text. 

CSI 7 m 



SETTING VISUAL CHARACTER AND LINE ATTRIBUTES 115 



Notes on SGR 

• After you select an attribute, the terminal applies that attribute to 
all new characters received. If you move characters by scrolling, the 
attributes move with the characters. 

• If you display control characters, the terminal ignores the bold attri- 
bute for displayed control characters. See "Display Controls Mode" 
at the end of Chapter 2. 

SETTING LINE ATTRIBUTES 

Line attributes are display features that affect the way a line of characters ap- 
pears on the screen. For example, the double-width, single height line 
(DECDWL) attribute makes a line of characters appear twice as wide as a nor- 
mal line of characters. This section describes how to select line attributes. 

Single-Width, Single-Height Line (DECSWL) 

This control function makes the line with the cursor single-width and single- 
height. This line attribute is the standard for all new lines on the screen. 

ESC # 5 

1/11 2/3 3/5 

Double-Width, Single-Height Line (DECDWL) 

This control function makes the line with the cursor double-width and single- 
height. If the line was single-width and single-height, all characters to the right 
of the screen's center are lost. 

ESC # 6 

1/11 2/3 3/6 

Double-Width, Double-Height Line (DECDHL) 

These two control functions make the line with the cursor the top or bottom 
half of a double-height, double-width line. You must use these sequences in 
pairs on adjacent lines. In other words, the same display characters must ap- 
pear in the same positions on both lines to form double-height characters. If 
the line was single-width and single-height, all characters to the right of the 
screen center are lost. 

Top Half Bottom Half 

ESC # 3 ESC # 4 

1/11 2/3 3/3 1/11 2/3 3/4 



116 SETTING VISUAL CHARACTER AND LINE ATTRIBUTES 



Example 

The following sequences make the phrase "VT300 Video Terminal" double- 
height and double-width. 

ESC#3 VT300 Video Terminal 
ESC#4 VT300 Video Terminal 

SUMMARY 

Table 7-2 lists the control functions described in this chapter. 

Table 7-2 Character and ! .inc. Attribute S*:q!MiBr.es 



Name 


Mnemonic 


.' Sequence 


Select graphic 
rendition 


SGR 


CSI Ps...Ps m 

Ps = character attribute value(s) 
(Table 7-1) 


Single-width, 
single-height line 


DECSWL 


ESC » 5 


Double-width, 
single-height line 


DECDWL 


ESC # 6 


Double-width, 
double-height line 


DECDHL 


ESC # 3 (top half) 
ESC t 4 (bottom half) 



SETTING VISUAL CHARACTER AND LINE ATTRIBUTES 117 



8 



EDITING 

AND 

CHARACTER PROTECTION 



Editing, 119 

Erasure Mode (ERM), 119 

Insert/Replace Mode (IRM), 119 

Delete Line (DL), 120 

Insert Line (IL), 121 

Delete Character (DCH), 121 

Insert Character (ICH), 122 

Erase in Display (ED), 122 

Erase in Line (EL), 123 

Erase Character (ECH), 124 

Selective Erase in Display (DECSED), 124 

Selective Erase in Line (DECSEL), 125 
Character Protection, 126 
Independent Protection, 126 

How It Differs from Visual Attribute Protection, 127 

Select Character Protection Attribute (DECSCA), 127 

Start Protected Area (SPA) and End Protected Area (EPA), 128 
Visual Attribute Protection, 129 

How It Differs From Independent Protection, 129 

Protected Fields Attributes (DECPRO), 129 
Summary, 131 



You use editing control functions to insert, delete, and erase characters and 
lines of characters at the cursor position. You use character protection control 
functions to protect characters in the terminal's page memory. Protected char- 
acters cannot be changed, erased, or moved by certain editing control functions. 

This chapter describes how to edit and protect characters in page memory. 
118 



EDITING 

This section describes the editing control functions available in the VT300. The 
cursor does not move when you use these functions. 

Erasure Mode (ERM) 

This control function determines whether the erasure functions can edit pro- 
tected characters. Table 8-1 lists the functions that ERM affects. ERM also 
affects the independent style of character protection. See "Character 
Protection" later in this chapter for information on protection styles. 



Default: Unprotected. 

Mode Sequence 



Set 
(All) 


CSI 

9/11 


6 
3/6 


h 
6/8 


Reset 
(Unprotected) 


CSI 

9/11 


6 
3/6 


1 
6/12 


Notes on ERM 









Action 

Erasure functions (ED, EL, 
and ECH) can affect all charac- 
ters, protected and unprotected. 

Erasure functions (ED, EL, 
and ECH) can affect only 
unprotected characters. 



• ERM does not affect the selective erase functions (DECSED, 
DECSEL). DECSED and DECSEL can never erase protected char- 
acters, regardless of the setting of ERM. 

• In edit mode (DECEDM): ERM also affects the following editing 
functions: DL, IL, DCH, ICH. See Chapter 9. 

Table 8-1 Control Functions Affected by Character Protection 



Always ■ 

Erase character (ECH) 
Erase in line (EL) i V; '■■■ 
Erase in display (ED) 



If Edit Mode (DECEDM) Is Set 

Insert character (ICH) 

Insert line (ID 

Delete character (DCH) 

Delete line (DL) 



Insert/Replace Mode (IRM) 

This control function selects how the terminal adds characters to page memory. 
The terminal always adds new characters at the cursor position. 



EDITING AND CHARACTER PROTECTION 119 



Default: Replace. 



Mode 



Sequence 



Action 



Set 


CSI 4 h 


Selects insert mode. 


(Insert) 


9/11 3/4 6/8 


New characters move charac 
ters in page memory to the 
right. 



Characters moved past the 
right page border are lost from 
page memory. 



Reset 


CSI 4 1 


Selects replace mode. 


(Replace) 


9/11 3/4 6/12 


New characters replace the 
character at the cursor posi 
tion. 



Notes on IRM 



If erasure mode (ERM) is reset, text moved into a protected charac- 
ter field is lost. 



Delete Line (DL) 

This control function deletes one or more lines in the scrolling region, starting 
with the line that has the cursor. 

CSI Pn M 

9/11 3/? 4/13 

where 



Pn is the number of lines to delete. 
Default: Pn = 1. 

As lines are deleted, lines below the cursor and in the scrolling region move up. 
Blank lines with no visual attributes are added at the bottom of the scrolling 
region. If Pn is greater than the number of lines remaining on the page, DL 
deletes only the remaining lines. DL has no effect outside the scrolling 
margins. 



120 EDITING AND CHARACTER PROTECTION 



Notes on DL 

• In edit mode (DECEDM): If erasure mode (ERM) is reset, DL can- 
not delete lines that have protected characters. As lines are deleted, 
the area moved up is bounded by the bottom of the scrolling region, 
or by the next line with a protected character field. See Chapter 9. 

Insert Line (IL) 

This control function inserts one or more blank lines, starting at the cursor. 

CSI Pn L 

9/11 3/? 4/12 

where 

Pn is the number of lines to insert. 
Default: Pn = 1 

As lines are inserted, lines below the cursor and in the scrolling region move 
down. Lines scrolled off the page are lost. IL has no effect outside the page 
margins. 

Notes on IL 

• In edit mode (DECEDM): If erasure mode (ERM) is reset, lines that 
move down into a line with a protected character field are lost. See 
Chapter 9. 

Delete Character (DCH) 

This control function deletes one or more characters, from the cursor position 
to the right. 

CSI Pn P 

9/11 3/? 5/0 

where 

Pn is the number of characters to delete. If Pn is greater than the number 
of characters remaining on the line, DCH only deletes the remaining 
characters. 
Default: Pn = 1. 

As characters are deleted, characters to the right of the cursor move left. 
Character attributes move with the characters. The spaces created at the end 
of the line have all attributes off. 



EDITING AND CHARACTER PROTECTION 121 



Notes on DCH 

In edit mode (DECEDM) 

— If erasure mode (ERM) is reset, DCH cannot delete protected 
characters. 

— If characters are protected by the DECPRO function, DCH can- 
not delete protected characters. See Chapter 9. 

Insert Character (ICH) 

This control function inserts one or more space (SP) characters, starting at the 
cursor position. 

Available in: VT300 mode only 

CSI Pn @ 

9/11 3/? 4/0 

where 

Pn is the number of characters to insert. 
Default: Pn = 1. 

The ICH sequence inserts Pn blank characters with the normal character attri- 
bute. The cursor remains at the beginning of the blank characters. Text to the 
right of the cursor moves right. Characters scrolled off the page are lost. 

Notes on ICH 

• In edit mode (DECEDM): If erasure mode (ERM) is reset, text 
moved into a protected character field is lost. See Chapter 9. 

Erase in Display (ED) 

This control function erases characters from part or all of the display. When 
you erase complete lines, they become single-height and single-width, with all 
visual character attributes cleared. ED works inside or outside the current 
margins 

CSI Ps J 

9/11 3/? 4/10 



122 EDITING AND CHARACTER PROTECTION 



where 

Ps represents the amount of the display to erase, as follows. 

Ps Area Erased 

(default) From the cursor through the end of the display 

1 From the beginning of the display through the cursor 

2 The complete display 

PROGRAMMING TIP: Use a Ps value of 2 to erase the complete display in a 
fast, efficient manner. 

Notes on ED 

• If erasure mode (ERM) is reset, ED cannot erase protected charac- 
ter positions. 

Erase in Line (EL) 

This control function erases characters on the line that has the cursor. EL 
clears all character attributes from erased character positions. EL works inside 
or outside the current margins. 

CSI Ps K 

9/11 3/? 4/11 

where 

Ps represents the section of the line to erase, as follows. 

Ps Section Erased 

(default) From the cursor through the end of the line 

1 From the beginning of the line through the cursor 

2 The complete line 



Notes on EL 



If erasure mode (ERM) is reset, EL cannot erase protected 
characters. 



EDITING AND CHARACTER PROTECTION 123 



Erase Character (ECH) 

This control function erases one or more characters, from the cursor position to 
the right. ECH clears character attributes from erased character positions. 
ECH works inside or outside the current margins. 

Available in: VT300 mode only 

CSI Pn X 

9/11 3/? 5/8 

where 

Pn is the number of characters to erase. A Pn value of or 1 erases one 

character. 

Default: Pn = 1. 

Notes on ECH 

• If erasure mode (ERM) is reset, ECH cannot erase protected 
characters. 

Selective Erase in Display (DECSED) 

This control function erases some or all of the erasable characters in the dis- 
play. DECSED can only erase characters defined as erasable by the DECSCA, 
SPA, or EPA control functions. See "Character Protection" later in this chap- 
ter for details. DECSED works inside or outside the scrolling margins, except 
in edit mode (DECEDM). In edit mode, DECSED cannot erase characters out- 
side the scrolling margins. 

Available in: VT300 mode only 

CSI ? Ps J 

9/11 3/15 3/? 4/10 

where 

Ps represents the area of the display to erase, as follows. 

Ps Area Erased 

(default) From the cursor through the end of the display 

1 From the beginning of the display through the cursor 

2 The complete display 

124 EDITING AND CHARACTER PROTECTION 



Notes on DECSED 

• DECSED is not affected by erasure mode (ERM). 

• DECSED does not affect visual character attributes set by the se- 
lect graphic rendition (SGR) function, or selection attributes set with 
SSA or ESA functions (Chapter 9). 

• DECSED provides full compatibility with applications that use the 
VT220 selective erase feature. 

Selective Erase in Line (DECSEL) 

This control function erases some or all of the erasable characters in a single 
line of text. DECSEL erases only those characters defined as erasable by the 
DECSCA, SPA, or EPA control functions. See "Character Protection" later in 
this chapter for details. DECSEL works inside or outside the scrolling margins, 
except in edit mode (DECEDM). In edit mode, DECSEL cannot erase charac- 
ters outside the scrolling margins. 

Available in: VT300 mode only 

CSI ? Ps K 

9/11 3/15 3/? 4/11 

where 

Ps represents the section of the line to erase, as follows. 

Ps Section Erased 

(default) From the cursor through the end of the line 

1 From the beginning of the line through the cursor 

2 The complete line 

Notes on DECSEL 

• DECSEL is not affected by erasure mode (ERM). 

• DECSEL does not affect visual character attributes set by the select 
graphic rendition (SGR) function. 

• DECSEL provides full compatibility with applications that use the 
VT220 selective erase feature. 

EDITING AND CHARACTER PROTECTION 125 



CHARACTER PROTECTION 

You can protect character positions in the terminal's page memory. Protected 
characters cannot be changed, erased, or moved by certain editing control func- 
tions (such as ED, EL, or ECH). 

There are two styles of character protection available. 

• Independent protection 

• Visual attribute protection 

You should use only one style of protection at a time. The two styles do not 
protect characters in the same way. To avoid confusion, Digital recommends 
that you use only one style of protection for each text form you design. 

The following sections describe each style of character protection and list the 
editing control functions affected. 

PROGRAMMING TIP: Digital recommends that new applications use indepen- 
dent protection. Visual attribute protection is only provided for strict compati- 
bility with Digital's VT131 terminal. 

INDEPENDENT PROTECTION 

This style of character protection lets you protect all the characters in an area 
of page memory, independent of their visual attributes (such as bold and under- 
line). When you use independent protection, the following control functions can- 
not change, erase, or move the protected characters. 

Erase in display (ED) 
Erase in line (EL) 
Erase character (ECH) 

In addition, if you set edit mode (DECEDM), the following control functions 
cannot change, delete, or move protected characters. 

Insert line (IL) 
Insert character (ICH) 
Delete line (DL) 
Delete character (DCH) 

See Chapter 9 for details on edit mode. 



126 EDITING AND CHARACTER PROTECTION 



How It Differs from Visual Attribute Protection 

There are three basic differences between independent protection and visual 
attribute protection. 

• Independent protection lets you protect characters independent of 
their visual character attributes. Visual attribute protection applies to 
characters with the same visual character attribute. 

• You can use independent protection in any operating mode. You can 
use visual attribute protection only in edit mode (Chapter 9). 

• Independent protection depends on the current setting of erasure 
mode (ERM), visual attribute protection does not. 

ERM determines whether or not independently protected characters 
can be changed, erased, or moved. 

ERM set All characters can be changed, erased, or moved, 

regardless of protection. 

ERM reset Only unprotected characters can be changed, 

erased, or moved (using the erasure control 
functions). 

See "Erasure Mode (ERM)" earlier in this chapter for details. Table 
8-1 describes how erasure mode (ERM) affects protected characters. 

For more details, see "Visual Attribute Protection" later in this chapter. 

NOTE: You should use only one style of protection at a time. The two styles of 
protection (independent and visual attribute) do not protect characters in the 
same way. To avoid confusion, use only one style of protection for each text 
form you design. 

PROGRAMMING TIP: Digital recommends that new applications use indepen- 
dent protection. Visual attribute protection is only provided for strict compati- 
bility with Digital's VT131 terminal. 

The following sections describe the control functions you use to define areas of 
page memory as independently protected. 

Select Character Protection Attribute (DECSCA) 

This control function defines successive characters written to page memory as 
protected or unprotected. The erasure control functions (ED, EL, or ECH) can- 
not erase protected characters. 



EDITING AND CHARACTER PROTECTION 127 



Available in: VT300 mode only 



CSI Ps 

9/11 3/? 



2/2 



q 

7/1 



where 



Ps defines all following characters as protected or unprotected. 



Ps 

(default) 

1 

2 

Notes on DECSCA 



Meaning 

Not protected. 

Protected. 

Not protected. Same as default setting. 



• DECSCA does not affect visual character attributes set by the select 
graphic rendition (SGR) function. 

• If erasure mode (ERM) is set, you can erase protected characters by 
using the ED, EL, or ECH functions. 

Start Protected Area (SPA) and End Protected Area (EPA) 

These control functions define the beginning and end of a protected area in 
page memory. The erasure control functions (ED, EL, and ECH) cannot change 
protected areas. 

You can represent SPA or EPA as an 8-bit control character, or as a 7-bit 
escape sequence. 



Action 

Defines the cursor position 
as the beginning of a series 
of protected characters. 

Defines the cursor position 
as the end of a series of 
protected characters. 



Notes on SPA and EPA 

• The terminal ignores any EPA received before an SPA. 

• If SPA is not followed by an EPA on the same page, SPA has no 
effect on the page. 



Name 


8-Bit 


7-Bit 




Start of 


SPA 


ESC 


V 


protected 


9/6 


1/11 


5/6 


area (SPA) 








End of 


EPA 


ESC 


W 


protected 


9/7 


1/11 


5/7 


area (EPA) 









128 EDITING AND CHARACTER PROTECTION 



VISUAL ATTRIBUTE PROTECTION 

This style of character protection lets you protect characters with the same 
visual attribute in an area of page memory. When you use visual attribute pro- 
tection, the following control functions cannot change, erase, or move protected 
characters. 

Insert character (ICH) Erase character (ECH) 

Insert line (IL) Erase in line (EL) 

Delete character (DCH) Erase in display (ED) 
Delete line (DL) 

How It Differs from Independent Protection 

There are three basic differences between visual attribute protection and inde- 
pendent protection. 

• Visual attribute protection applies to characters with the same visual 
character attribute. For example, you can protect all characters with 
the bold attribute or underline attribute. Independent protection is 
independent of visual attributes. 

• Visual attribute protection is only available in edit mode (DECEDM). 
You can use independent protection in all operating modes. 

• Visual attribute protection is not affected by erasure mode (ERM). 
Independent protection is affected. 

NOTE: You should use only one style of protection at a time. The two styles of 
protection (independent and visual attribute) do not protect characters in the 
same way. To avoid confusion, use only one style of protection for each text 
form you design. 

PROGRAMMING TIP: Digital recommends that new applications use indepen- 
dent protection. Visual attribute protection is only provided for strict compati- 
bility with Digital's VT131 terminal. 

You use the DECPRO control function to protect characters based on their vi- 
sual attributes. 

Protected Fields Attributes (DECPRO) 

This control function selects character protection based on visual attributes. 
Available in: edit mode (DECEDM) 

CSI Ps ... Psn } 

9/11 3/? ... 3/? 7/13 

EDITING AND CHARACTER PROTECTION 129 



where 

Ps defines characters with a certain character attribute as protected or 
unprotected. You can select more than one attribute. 

Characters Affected 

Characters with no attribute (normal) 
Bold characters 
Underlined characters 
Blinking characters 
Negative image characters 
Invisible characters 

Bold characters 
Underlined characters 
Blinking characters 
Negative image characters 
Invisible characters 
All characters 

When you select more than one attribute in a DECPRO sequence, any charac- 
ter position with one or more of the selected attributes is protected. 



Ps 


Protection 





On 


1 


On 


4 


On 


5 


On 


7 


On 


8 


On 


22 


Off 


24 


Off 


25 


Off 


27 


Off 


28 


Off 


254 


Off 



Examples 



The following sequence protects characters with the bold attribute, 
blinking attribute, or both attributes. 

CSI ; 1 ; 5 } 

The following sequence protects only characters with the underline 
attribute. 



CSI 4 } 
Notes on DECPRO 



DECPRO does not change the appearance of characters (their visual 
attributes). DECPRO only changes the protection of characters for 
editing. 

DECPRO is only available in edit mode (DECEDM). You can use 
both styles of protection (independent or visual attribute) in edit 
mode. 



130 EDITING AND CHARACTER PROTECTION 



SUMMARY 

Tables 8-2 and 8-3 list the control functions described in this chapter. 

Tubie 8-2 Editing Setfuewtes 



Name 


Mnemonic 


.■■ Sequence 


Erasure mode 


ERM 


Set: CSI 6 li 

You can edit all characters. 

Reset: CSI G 1 

You can m^y edit unprotected characters 

(D) 


Insert/ 


IRM 


Set: CSI 4 h 


replace. 




Insert characters. 


mode 




Reset: CSI 4 I 

Replace characters. 


Delete line 


DL 


CSI Pn M 

.. Pn lines. 


Insert line 


IL 


CSI Pn L 

Pn lines. 


Delete 


DCH 


CSI Pn P 


character 




Pn characters. 


Insert:'-;'.' 


ICH 


CSI Pn @ 


character 




Pn characters. 



ID) = default. 



EDITING AND CHARACTER PROTECTION 131 



Table 8-2 


Ed 


itiug Sequences 


(Cont) ■'■ 


Name 




Mnemonic 




Sequence 


Erase 




ED 




CSI Ps J 


in display 








Ps = 0. cursor to end. (D) 
Ps = 1 . beginning to cursor 
Ps = 2. complete display. 


Erase in line 




EL 




CSI Ps K 



Erase 


ECH 


character* 




Selective 


DECSED 


erase 




in display* 




Selective 


DECSEL 


erase 




in line* 





Ps = 0. cursor to end. |D) 
Ps = 1. beginning to cursor. 
Ps = 2. complete line. 

CSI Pn X 

Pn characters. 

CSI ? Ps J 

Ps = 0. cursor to end. (D) 
Ps = 1 , beginning to cursor. 
Ps = 2. complete display. 

CSI ? Ps K 

Ps = 0, cursor to end. (Dl 
Ps = 1. beginning to cursor. 
Ps = 2, complete line. 



ID) = default. 

* Available in VT300 mode only. 



132 EDITING AND CHARACTER PROTECTION 



Table 8-3 Character Protection Sequences 

Name Mnemonic Sequence 

Independent Protection 

Select character DECSCA CSI Ps " q 

attribute* Ps = or 2, unprotected. (D) 

Ps = 1, protected. 

Start protected SPA 8-bit: SPA 

area 7-bit: ESC V 

End protected EPA 8-bit: EPA 

area 7-bit: ESC W 

Visual Attribute Protection (For Local Editing Only) 

Protected fields DECPRO CSI Ps } 

attribute Ps = character attribute value. 

See "Setting Visual Character Attributes." 

* Available in VT300 mode only. 



EDITING AND CHARACTER PROTECTION 133 



9 



LOCAL EDITING 



How Local Editing Works, 135 

What Control Functions Do You Use?, 135 
Selecting Edit Mode, 136 

Edit Mode (DECEDM), 136 

Edit Key Execution Mode (DECEKEM), 136 
Defining the Size of the Character Block. 137 

Line Transmit Mode (DECLTM), 138 

Transmit Termination Mode (TTM), 139 

VT131 Transmit Mode (DEC131TM), 140 
Selecting the Characters to Send, 141 

Guarded Area Transfer Mode (GATM), 141 

Selected Area Transfer Mode (SATM), 142 

Multiple Area Transfer Mode (MATM), 143 

Defining Selected Areas, 143 

Start Selected Area (SSA) and End Selected Area (ESA), 143 
End-of-Block and Unused Space Characters, 144 

Set Transmit Termination Character (DECTTC), 144 

Transmit Line Termination Characters (DECTLTC), 146 

Space Compression Mode (DECSCFDM), 147 
Sending Edited Data to the Host, 148 

Transmit Execution Mode (DECTEM), 148 

Set Transmit State (STS), 149 

Transmit Mode (DECXMIT), 149 
Block Transmission Examples, 149 
Character Sets and Block Transmission, 153 

Block Transmission in an 8-Bit Environment, 153 

Block Transmission in an 7-Bit Environment, 154 
Summary, 156 



134 



HOW LOCAL EDITING WORKS 

The VT300 can operate as an interactive or editing terminal. As an interactive 
terminal, the VT300 immediately sends each character you type to the host 
computer. Host software must perform any editing functions. 

As an editing terminal, the VT300 does not send your typed characters imme- 
diately to the host. Instead, the terminal stores the characters in its page 
memory and displays them on the screen. You can edit the displayed charac- 
ters, then send them to the host in a single block. The terminal performs your 
editing functions locally. 

NOTE: Local editing requires host software support. 

By using the local editing feature, applications can free the host from editing 
tasks. You can edit as much data as you can store in page memory. You send 
the block of edited data to the host by using a control function. The terminal 
locks the keyboard until the transmission is complete. 

What Control Functions Do You Use? 

In edit mode, you can use the erasure, deletion, and insertion control functions 
described in Chapter 8. You can also use either style of character protection, 
independent or visual attribute. 

The character protection feature lets you design text forms that cannot be 
changed or overwritten. In edit mode, character protection also depends on the 
setting of erasure mode (ERM). 

• If ERM is set, all characters can be changed, erased, and moved, 
regardless of protection. 

• If ERM is reset, only unprotected characters can be changed, 
erased, and moved. The following control functions will not affect 
protected areas in page memory. 

Insert line (IL) Erase in display (ED) 

Delete line (DL) Erase in line (EL) 

Insert character (ICH) Erase character (ECH) 
Delete character (DCH) 

This chapter describes how to select local editing and send edited data to the 
host. The chapter also describes how to select what areas of page memory you 
send to the host. For example, you may not want to send protected areas to 
the host. 



LOCAL EDITING 135 



SELECTING EDIT MODE 

There are two ways to select edit mode. Applications can use the edit mode 
(DECEDM) sequence, or you can press Shift-EDIT. 

Edit Mode (DECEDM) 

This control function selects edit mode or interactive mode. This function deter- 
mines when the terminal sends data to the host. 

Default: Interactive mode 



Mode 



Sequence 



Set 


CSI ? 1 h 


(Edit mode) 


9/11 3/15 3/1 3/0 6/8 



Reset 

(Interactive 

mode) 



CSI ? 10 1 

9/11 3/15 3/1 3/0 6/12 



Action 

Selects edit mode. (Turns 
on the edit mode indicator 
on the status line.) The 
terminal stores all typed 
characters in page memory, 
for local editing. After 
you edit the stored data, 
you can send it in a block 
to the host. 

Selects interactive mode. 
(Turns off the edit mode 
indicator.) The terminal 
immediately sends typed 
characters to the host. 



Edit Key Execution Mode (DECEKEM) 

You can switch between edit mode and interactive mode by pressing Shift- 
EDIT. This control function determines if the terminal switches modes immedi- 
ately or when the application decides. 



Default: Immediate 

Mode Sequence 



Set 
(Immediate) 



CSI ? 16 h 

9/11 3/15 3/1 3/6 6/8 



Action 

When you press Shift-EDIT, 
the terminal immediately 
switches between 
interactive and edit 
modes. 



136 LOCAL EDITING 



Reset 


CSI ? 16 1 


(Deferred) 


9/11 3/15 3/1 3/6 6/12 



When you press Shift-EDIT, 
the terminal sends DECEDM 
(set or reset) to the host 
to switch modes. Then the 
terminal waits for the 
host to return DECEDM to 
change the terminal's 
current mode. 

DEFINING THE SIZE OF THE CHARACTER BLOCK 

In edit mode, you can select which data the terminal sends to the host. The 
amount of data sent depends on two factors. 

• the size of the character block you define 

• the areas of text you select as eligible to send 

This section describes how to define the size of the character block. The next 
section describes how to select areas of page memory as eligible to send. 

You can send up to a page of data at one time. You can use three control 
functions to define the size of the character block sent to the host. 

Line transmit mode (DECLTM) 
Transmit termination mode (TTM) 
VT131 transmit mode (DEC131TM) 

Table 9-1 lists the block sizes you can select with these functions. You can 
select from three different block sizes. 

VT131 partial page 

Includes the text on the current page between the partial page marker and 
the cursor. The partial page marker does not appear on the screen. The 
terminal automatically places the marker at the position of the last charac- 
ter sent. If there is no marker, or the marker is after the cursor, the ter- 
minal sends all eligible characters between the top margin and the cursor. 

ANSI partial page 

Includes the text on the current page from the beginning of a selected 
area to the cursor. A selected area is a block of text that is selected as 
eligible to send to the host. 



LOCAL EDITING 137 



Scrolling region 

Includes the text of the current page that is inside the margins. 

Table 9-1 Defining the Character Block Size for Transmission 





■Line 


TraHSmlt 


VT131 




Transmit 


Termination 


Transmit 




Mode 


Mode 


Mode 


Block Size 


(DECLTM) 


(TTM) 


(DEC131TM) 


Line 


Set. 


— 


— 


VT131 partial page 


Reset 


Reset 


Set 


ANSI partial page fy. - /:■':';'. 


Reset 


Reset 


' Reset ■ 


Scrolling region . 


Reset 


Set 


_ 



Line Transmit Mode (DECLTM) 

This control function lets you select one of two options for the size of the char- 
acter block. 

• a line of characters 

• a full or partial page 

To select a scrolling region or partial page, you must also use transmit termina- 
tion mode (TTM) and VT131 transmit mode (DEC131TM). 

In a line transmission, the terminal sends eligible characters from the line with 
the cursor. These characters are followed by any end-of-line characters and end- 
of-block characters. To start a line transmission, you can press the Return or 
Enter key. 

If you press Return to start a line transmission, the cursor moves to the left 
page border of the active line. If you press Enter to start a line transmission, 
the cursor does not initially move. 

If line feed/new line mode is set, the cursor moves to the first unprotected field 
in the next line. 

If the cursor is at the end of scrolling region, the cursor moves to the first 
unprotected field on the current line. 

DECLTM applies only in edit mode (DECEDM). 



138 LOCAL EDITING 



Default: Page of characters 
Mode Sequence 



Action 



Set 
(Line) 


CSI 

9/11 


1 

3/15 


1 
3/1 


1 h 

3/1 6/8 


Reset 
(Page) 


CSI 

9/11 


? 
3/15 


1 

3/1 


1 1 
3/1 6/12 



Selects line transmission. 

Selects full or partial page 
block transmission, depending 
on the settings of transmit 
termination mode (TTM) and 
VT131 transmit mode (VT131TM). 



Notes on DECLTM 

• When DECLTM is reset (page), TTM and VT131TM let you select 

from three block sizes: VT131 partial page, ANSI partial page, or 
the scrolling region. 

Transmit Termination Mode (TTM) 

If line transmit mode (DECLTM) is reset (page), transmit termination mode 
(TTM) and VT131 transmit mode (DEC131TM) define the size of the character 
block. TTM determines whether the terminal includes the cursor position as 
part of the criteria that ends a block transmission. 

Default: Scrolling region 

Mode Sequence Action 



Set 

(Scrolling 

region) 

Reset 

(Partial 

page) 



CSI 1 6 h 

9/11 3/1 3/6 6/8 



CSI 

9/11 



1 6 1 
3/1 3/6 6/12 



The terminal sends the scrolling 
region. 

The terminal sends a VT131 or 
or ANSI partial page, based on 
VT131 transmit mode (DEC131TM). 



DEC131TM Selects 



Set 
Reset 



VT131 partial page 
ANSI partial page 



LOCAL EDITING 139 



Notes on TTM 

• When you select a VT131 partial page, the terminal sends all eligible 
characters between the partial page marker and the cursor. If there 
is no marker, or the marker is after the cursor, the terminal sends 
all eligible characters between the top margin and the cursor. 

The partial page marker does not appear on the screen. The termi- 
nal automatically places the marker at the position of the last char- 
acter sent. 

You use this setting for compatibility with the VT131 terminal. 

• When you select an ANSI partial page, the terminal sends all eligi- 
ble characters from the beginning of a selected area to the cursor. 

VT131 Transmit Mode (DEC131TM) 

If line transmit mode (DECLTM) is reset (page), DEC131TM and transmit ter- 
mination mode (TTM) together define the size of the character block the termi- 
nal can send to the host. You cannot use DEC131TM and TTM separately. 

Table 9-1 shows how the terminal determines the size of the character block to 
send. Table 9-2 shows how the terminal determines which characters are eligi- 
ble to send. 

Default: ANSI 



Mode 



Sequence 



Set 
(VT131) 


CSI 

9/11 


3/15 


5 

3/5 


3 
3/3 


h 

6/8 


Reset 

(ANSI) 


CSI 

9/11 


? 

3/15 


5 

3/5 


3 

3/3 


1 
6/12 



Action 

The terminal works like a 
VT131 terminal. 

The terminal works according 
to ANSI rules. 



140 LOCAL EDITING 



Table 9-2 Selecting Character Fields for Transmission 



Fields Selected 

All fields 

Unprotected 
fields only 

Selected fields 
only 

Selected field 
with cursor only 

Unprotected 

and selected fields 

Unprotected fields 
and selected field 
with cursor 



SELECTING THE CHARACTERS TO SEND 

There are five control functions that select which characters the terminal can 
send to the host. 



Guarded Area 


Selected Area 


Multiple Area 


Transfer 


Mode 


Transfer Mode 


Transfer Mode 


(GATM) 




(SATM) 


(MATM) 


Set 




Set 


Not available 


Reset 




Set 


Not available 


Set 




Reset 


Set 


Set 




Reset 


Reset 


Reset 




Reset 


Set 


Reset 




Reset 


Reset 



Function 

Guarded area transfer mode (GATM) 

Selected area transfer mode (SATM) 
Mui Jple area transfer mode (MATM) 

Start selected area (SSA) 
End selected area (ESA) 



Use 

Send protected areas. 

Send one or all selected areas. 

Define a selected area. 



The following sections describe each control function. Table 9-2 shows how 
these functions select which characters the terminal sends. Table 9-1 shows 
how other functions select the size of the character block to send. 

Guarded Area Transfer Mode (GATM) 

This control function selects whether the terminal can send all characters or 
only unprotected characters to the host. See "Character Protection" in Chapter 
8 for information on the two styles of character protection available. 



LOCAL EDITING 141 



Default: All characters 



Mode 

Set 
(All) 



Reset 
(Unprotected) 



Sequence 

CSI 1 h 

9/11 3/1 6/8 



CSI 1 I 

9/11 3/1 6/12 



Action 

Selects all characters. 
During block transmission, 
the terminal can send all 
protected and unprotected 
characters to the host. 

Selects unprotected 
characters. During a block 
transmission, the terminal 
can send only unprotected 
characters to the host. 



Notes on GATM 

• When GATM is reset (unprotected), the terminal sends a record sep- 
arator (RS, 1/14) to the host in place of a protected field. The termi- 
nal sends a space character (SP, 2/0) to a printer in place of a 
protected field. 

Selected Area Transfer Mode (SATM) 

This control function determines whether the terminal can send all characters 
or only selected characters to the host. Selected characters are characters de- 
fined as eligible to send to the host. 

You can define selected areas on the current page with the start selected area 
(SSA) and end selected area (ESA) control functions. 



Default: All characters 



Mode 



Sequence 



Action 



Set 

(All) 




CSI 

9/11 


1 

3/1 


7 
3/7 


h 

6/8 


Selects all characters. 

The terminal can send selected 

and unselected characters 

on the current page to the 

host. 


Reset 

(Selected 

only) 


CSI 

9/11 


1 
3/1 


7 
3/7 


1 

6/12 


Selects only selected 
characters. The terminal 


142 


LOCAL EDITING 











can only send selected 
characters on the current 
page to the host. 

Multiple Area Transfer Mode (MATM) 

This control function determines what selected character areas the terminal can 
send to the host. MATM only works when selected area transfer mode (SATM) 
is reset. 

Default: All selected areas 



Mode 



Sequence 



Set 
(All) 


CSI 

9/11 


1 

3/1 


5 

3/5 


h 

6/8 


Reset 
(One area) 


CSI 

9/11 


1 

3/1 


5 

3/5 


1 
6/12 


Notes on MATM 











Action 

The terminal can send all 
selected areas on the page to 
the host. 

Selects one area. The terminal 
can send only the selected area 
with the cursor. 



• If MATM is reset (one area) and the cursor is not in a selected field, 
the cursor moves to the next selected field. 

Defining Selected Areas 

The next two control functions select what characters are eligible to send to 
the host. Eligible characters are called selected characters. 

Start Selected Area (SSA) and End Selected Area (ESA) - These two control 
functions select which characters on the current page the terminal can send to 
the host. SSA and ESA only work when selected area transfer mode (SATM) is 
reset. 

SSA and ESA are 8-bit CI control characters. You can also code SSA and 
ESA as 7-bit escape sequences. 



Name 


8-Bit 


7-Bit Equivalent 


Action 


Start selected 


SSA 


ESC F 


Marks the cursor 


area (SSA) 


8/6 


1/11 4/6 


position as the first 
of a string of 



LOCAL EDITING 143 



character positions the 
terminal can send to 
the host. 



End selected 


ESA 


ESC 


G 


Defines the cursor 


area (ESA) 


8/7 


1/11 


4/7 


position as the last 
of a string of 
character fields the 
terminal can send to 
host. 



Notes on SSA and ESA 



• If the terminal receives ESA before SSA, the terminal ignores ESA. 

• If SSA is not followed by ESA on the same page, the SSA has no 
effect on that page. Selected areas must always end with ESA. 

• Selected areas cannot be changed by the ED, EL, or ECH control 
functions. 

END-OF-BLOCK AND UNUSED SPACE CHARACTERS 

These control functions affect the way the terminal sends end-of-block, end-of- 
line, and space characters to the host in edit mode. 



Set transmit termination 
character (DECTTC) 

Set transmit line 
termination character 
(DECTLTC) 

Space compression mode 
(DECSCFDM) 



Selects one or more end-of-block 
characters. 

Selects one or more end-of-line 
characters. 

Determines whether or not to send 
unused space characters. 



Set Transmit Termination Character (DECTTC) 

This control function lets you select a character to indicate the end of a block 
transmission. You do not have to use an end-of-block character. The terminal 
sends the end-of-block character to the host at the end of each block 
transmission. 

CSI Ps | 

9/11 3/? 7/12 



144 LOCAL EDITING 



where 

Ps represents the end-of-block character, as follows. 



Ps 

(default) 

1 

2 
3 
4 
5 



End-of-Block Character 

No character (DECTTC disabled. 



FF 


form feed 


0/12 




ETX 


end of text 


0/3 




EOT 


end of transmission 


0/4 




CR 


carriage return 


0/13 




DC3 


XOFF 


1/3 





Extended Form 

An extended form of the DECTTC control function lets you select a string of 
characters to indicate the end of a block. This extended form uses decimal 
codes to represent characters. You can use the extended form to send a control 
function at the end of a block transmission, instead of a single character. You 
can send a control sequence of up to six characters (Pnl through Pn5) at the 
end of a block. 



CSI ? Pnl 

9/11 3/15 3/? 



3/11 



Pn6 | 
3/? 7/12 



where 



Pnl through Pn6 are decimal codes for characters that you can define as 
end-of-block characters. For example, the decimal code for the ESC (1/11) 
character is 27. The code table in Chapter 2 lists decimal codes for charac- 
ters. Any code value outside of the range of to 254 is ignored. 

Example 

Suppose you want to send the default code of the PF1 key on the numeric 

keypad at the end of a block transmission. You could use the following 

procedure. 



LOCAL EDITING 145 



1. The PF1 key sends the following default code. 

ESC O P 

1/11 4/15 5/0 

You must translate each character in the sequence to decimal code. 

2. Use the code table in Chapter 2 to find the decimal code for each 
character. 

ASCII characters: ESCO P 

Decimal codes: 27 79 80 

3. Now insert the decimal codes in the extended DECTTC sequence. 

CSI ? 27 ; 79 ; 80 | 

Transmit Line Termination Characters (DECTLTC) 

This control function lets you select the character(s) that the terminal sends to 
the host at the end of each line of transmitted data. 

Default: Carriage return (CR) — decimal code 13 

CSI ? Pnl ; ... Pn6 ' s 

9/11 3/15 ** 3/11 ** 2/7 7/3 

where 

Pnl through Pn6 are decimal codes for characters that you can define as 
end-of-line characters. The code table in Chapter 2 lists decimal codes for 
characters. Any code value outside of the range of to 254 is ignored. 

Example 

Suppose you want to send the default code of the Do key on the top row of 

function keys at the end of a block transmission. You could use the following 

procedure. 

1. The Do key sends the following default code. 

CSI 2 9 

9/11 3/2 3/9 7/14 



146 LOCAL EDITING 



You must translate each character in the sequence to decimal code. 

Use the code table in Chapter 2 to find the decimal code for each 
character. 



Characters: 
Decimal codes: 



CSI 2 9 " 

155 50 57 126 



Now insert the decimal codes in the DECTLTC sequence. 



CSI ? 155; 50; 57; 126 ' s 

Space Compression Mode (DECSCFDM) 

This control function determines whether the terminal sends space characters 
(SP, 2/0) at the end of characters fields. If the terminal does not send spaces, 
it uses the record separator character (RS, 1/14) to indicate the end of a field. 



Default: Spaces 

Mode Sequence 



Set 

(No spaces) 



CSI ? 13 h 

9/11 3/15 3/1 3/3 6/8 



Reset 
(Spaces) 



CSI ? 13 1 

9/11 3/15 3/1 3/3 6/12 



Action 

Selects space compression. 
The terminal does not send 
spaces characters at the end 
of a character field. 

All fields sent end with a 
single record separator (RS) 
character, except the last 
field on a line. The last 
field ends with the 
end-of-block character defined 
by the transmit termination 
character (DECTTC) function. 

Selects no space compression. 
The terminal sends space 
characters to the host at 
the end of a character field. 
The terminal sends characters 
as they appear on the page. 



LOCAL EDITING 147 



SENDING EDITED DATA TO THE HOST 

After you finish editing, you press the Enter key to send edited data to the 
host. Transmit execution mode (DECTEM) determines when the terminal actu- 
ally sends the data. 

Transmit Execution Mode (DECTEM) 

When you press Enter, this control function determines whether the terminal 
sends data immediately or waits for the host's permission. DECTEM operates 
only in edit mode (DECEDM). 

Default: Immediate 



Mode 



Sequence 



Action 



Set CSI ? 1 4 h 

(Immediate) 9/11 3/15 3/1 3/4 6/8 



Reset CSI ? 14 1 

(Deferred) 9/11 3/15 3/1 3/4 6/12 



When you press Enter, the 
terminal immediately sends 
a block of characters to 
the host. 

When you press Enter, the 
terminal sends a request 
to the host, asking if the 
host is ready to receive a 
block of characters. Then 
the terminal waits until 
the host responds. 



Notes on DECTEM 



When DECTEM is reset, the terminal requests a block transmission 
by sending the set transmit state (STS) sequence to the host. The 
host must respond with the DECXMIT sequence. 

If line transmit mode (DECLTM) is set, the Return key works like 
the Enter key. That is, pressing Return sends a block of characters 
to the host. 

See Installing and Using the VT330/VT340 Video Terminal for more 
information on sending characters to the host. 



148 LOCAL EDITING 



Set Transmit State (STS) — From Terminal 

The terminal sends this escape sequence to the host to request a block trans- 
mission. The terminal only sends STS when transmit execution mode 
(DECTEM) is reset. 

ESC S 

1/11 5/3 

Transmit (DECXMIT) — From Host 

The host responds to a set transmit state (STS) sequence by sending a 
DECXMIT sequence to the terminal. DECXMIT tells the terminal to send a 
block of characters. 

ESC 5 

1/11 3/5 

BLOCK TRANSMISSION EXAMPLES 

This section shows examples of what data the terminal sends to the host in a 
block transmission. The data sent depends on the settings of various local edit- 
ing control functions. 

Each example lists an initial set of conditions in effect. Then each example 
shows what data the terminal sends when you press the Transmit key, based 
on these conditions. 

All the examples are based on the screen in Figure 9-1. This screen is not 24 
lines by 80 columns. However, a full screen is not needed to illustrate block 
transmission. For the examples in this section, consider the screen in Figure 
9-1 to be a full page. The following conditions apply to this figure. 



• 



The asterisk * indicates the cursor position. 

Character positions in columns 1 through 9 are defined as protected 
from erasure or movement. These characters have their protection 
attribute set. 

Character positions in columns 10 through 39 on lines 13 through 
15 are defined as eligible for transmission. These characters have 
their selection attribute set. 

The top and bottom scrolling margins are set at lines 13 and 15 
respectively. 



LOCAL EDITING 149 



Name: 


John Doe 


Company: 


General Technology Corp. 


Part No: 


VR201 


Name: 


Video Monitor* 


Color: 


Amber 



10 

11 

12 

13 <- 
14 
15 <- 



-Top Margin 
-Bottom Margin 



13579111112222233333 
135791357913579 



Figure 9-1 Sending Data in Edit Mode 
The following abbreviations are used for characters in the examples. 



Character 


Abbreviation 


End-of-block 


<EOB> 


End-of-line 


<EOL> 


Record separator 


<RS> 


Example 1 




The following conditions 


are in effect. 


DECLTM reset 


Scrolling region 



GATM 


set 


All characters 


SATM 


set 




DECSCFDM 


reset 


Send spaces 



When you press Transmit, the terminal sends the following data. 



Part No:VR201 

Name: Video Monitor 

Color: Amber 



<E0L> 
<E0L> 
<E0L><E0B> 



150 LOCAL EDITING 



Example 2 

The following conditions are in effect. 



DECLTM 


reset 


Scrolling region 


TTM 


set 




DEC131TM 


set 




GATM 


reset 


Unprotected 


SATM 




characters in the 
scrolling region 
are selected for 
for transmission. 


DECSCFDM 


reset 


Send spaces 



When you press Transmit, the terminal sends the following data. 



VR201 

Video Monitor 

Amber 



<E0L> 
<EOL> 
<E0LXE0B> 



Example 3 

The following conditions are in effect. 



DECLTM 


reset 


Partial page 


TTM 


reset 




DEC131TM 


set 




GATM 


set 


All characters 


SATM 


set 




DECSCFDM 


set 


Do not send spaces 



When you press Transmit, the terminal sends the following data. 

Part No:<RS>VR20KE0L> 
Name:<RS>Video Monitor<E0L> 



LOCAL EDITING 151 



Example 4 

The following conditions are in effect. 

Page 



DECLTM 


reset 


TTM 


set 


DEC131TM 


reset 


GATM 


set 


SATM 


reset 


MATM 


reset 



Between active position and cursor 
reset 
reset 

DECSCFDM set Do not send spaces 

When you press Transmit, the terminal sends the following data. 
Video Moni tor<E0LXE0B> 

Example 5 

The following conditions are in effect. 



DECLTM 


reset 


Page 


TTM 


set 




DEC131TM 


reset 




GATM 


set 


All characters 


SATM 


set 




DECSCFDM 


set 


Do not send spaces 



When you press Transmit, the terminal sends the following data. 

Name :<RS>John Brown<E0L> 

Company :<RS>General Technology Corp.<E0L> 

<E0L> 

Part No:<RS>VR20KE0L> 

Name:<RS>Video Moni tor<EOL> 

Color:<RS>Amber<EOL><EOB> 

Example 6 

The following conditions are in effect. 



DECLTM 

TTM 

DEC131TM 



set 



Active line 



152 LOCAL EDITING 



GATM set All characters 

SATM set 

DECSCFDM reset Send spaces 

When you press Transmit, the terminal sends the following data. 

Name: Video Monitor <E0L><E0B> 



CHARACTER SETS AND BLOCK TRANSMISSION 

The terminal can send characters from several possible character sets during a 
block transmission. The VT300 sends characters based on the following general 
rules. 

• If space compression mode (DECSCFDM) is reset, the terminal 
sends unwritten character positions as SP (2/0). 

• The terminal never sends characters from the control representation 
(CRM) font. 

• Characters that are in page memory, but not available in the charac- 
ter sets in the in-use table, are sent as SUB (1/10). For example, 
characters that are not in the current user-preferred supplemental 
set, or unique NRC characters such as the Dutch florin are sent as 
SUB. 

The algorithm the terminal uses to send characters depends on whether the 
terminal is operating in an 8-bit or 7-bit environment. 

Block Transmission in an 8-Bit Environment 

National replacement character set mode (DECNRCM) is reset, and the termi- 
nal is in VT300 mode. The terminal selects the character set for each transmit- 
ted character as follows. 

NOTE; If the host communication line is set to 7 bits, data can be lost during 
a block transmission. The host forces the eighth bit of all received characters 
to 0. If the current host line is set to 7 bits, terminal cannot correctly send 
8-bit characters in a block transmission. 

1. At the beginning of a block transmission, the terminal assumes the 
ASCII set is in GL and the user-preferred supplemental set is in 
GR. 



LOCAL EDITING 153 



2. The VT300 sends ASCII graphic and SP characters with their 
eighth bit set to 0. The VT300 never sends a designating sequence 
for ASCII or space characters. 

3. For characters that are not ASCII characters or spaces, the VT300 
sends the appropriate G2 designating sequence for the character set 
containing those characters (Chapter 5). Then the VT300 sends the 
characters from that set. 

The VT300 always sends the actual designating sequence for the de- 
sired character set. This removes any ambiguity for applications that 
need to know which character set is currently defined as the user- 
preferred set (ISO Latin-1 or DEC Supplemental Graphic). 

NOTE; If the application sends the ISO level 1 announcer at the 
beginning of execution, the VT300 sends the appropriate Gl desig- 
nating sequence. 

4. If the same character is in more than one character set, the VT300 
uses the following priority system. 

— ASCII 

— User-preferred supplemental 

— DEC Technical 

— DEC Special Graphic 

After the VT300 selects the appropriate character set, the VT300 
sends the designating sequence, followed by the characters from the 
designated set. 

5. If the user-preferred character set is not in GR at the end of a block 
transmission, the VT300 sends a designating sequence to the host. 
This sequence specifies the current user-preferred supplemental set. 
The VT300 sends the designating sequence before the end-of-block 
character, if any. 

Block Transmission in a 7-Bit Environment 

National replace character set mode (DECNRCM) is set, or the terminal is in 
VT100 mode. The terminal selects the character set for each transmitted char- 
acter as follows. 



1. 



At the beginning of a block transmission, the terminal assumes that 
the ASCII set is in GL. 

The VT300 sends ASCII graphic and SP characters with their 
eighth bit set to 0. The VT300 never sends a designating sequence 
for ASCII or space characters. 



154 LOCAL EDITING 



3. For characters not in the ASCII set, the VT300 sends the appropri- 
ate GO designating sequence for the character set containing those 
characters (Chapter 5). Then the VT300 sends the characters from 
that set. 

The VT300 always sends the actual designating sequence for the de- 
sired NRC set. This removes any ambiguity for applications that 
need to know which NRC set (other than ASCII) is currently in GL. 

4. If the same character is in more than one character set, the VT300 
uses the following priority system. 

— ASCII 

— DEC Technical 

— DEC Special Graphic 

After the VT300 selects the appropriate character set, the VT300 
sends the designating sequence followed by the characters from the 
designated set. 

5. If the NRC set is not in GO at the end of a block transmission, the 
VT300 sends a designating sequence to the host. This designator 
specifies the current NRC set. The VT300 sends the designating se- 
quence before the end-of-block character, if any. 

PROGRAMMING TIP: You can program your application to be independent 
of the following settings. 

National replacement character set mode 

VT100 or VT300 mode 

ISO level 1 announcer (maps Gl into GR, instead of G2) 

To do this, make sure your application can accept 8-bit characters and desig- 
nating sequences for GO, Gl, or G2. See Chapter 5 for details on designating 
character sets. 



LOCAL EDITING 155 



SUMMARY 

Table 9-3 lists the control functions described in this chapter. You can only use 
these control functions in edit mode. 

Tablt- 9-3 Local Editing Sequences Summary 



Name 


Mnemonic 


Sequence 


Edit mode 


DECEDM 


Set: CSI ? 10 h 
Edit mode. 

Reset: CSI ? 10 1 
Interactive mode. 


Edit key 


DECEKEM 


Set: CSI ? 16 h 


execution mode 




Immediate. (D| 

Reset: CSI ? 16 I 
Deferred. 


I. me transmit 


DECLTM 


Set: CSI ? 11 h 


mode 




Line. 

Reset: CSI ? 1 1 1 
Page. (D) 


Ti ansmit 


TTM 


Set: CSI 16 b 


termination 




Scrolling region. (D) 


mode 




Reset: CSI 16 1 

■;.'■. Partial page. . 


VT131 


DEC131TM 


Set: CSI ? 53 h 


transmit 




VT131. 


mode 




Reset: CSI ? 53 1 
ANSI. ID) 


ID) = default. 







156 LOCAL EDITING 



Table 9-3 Local Editing Sequences Summary (Cout) 



Name 

Guarded area 

transfer mode 



Selected area 
transfer mode 



Multiple area 
transfer mode 



Mnemonic 

GATM 



SATM 



MATM 



Sequence 

Set: CSI I h 

All characters. ID) 

Reset: CSI 1 I 
Unprotected characters. 

Set: CSI 17 b 
All characters. ID) 

Reset: CSI 17 1 
Selected characters. 

Set: CSI 15 h 

All characters. (D) 

Reset: CSI 15 1 
Area with cursor. 



Start selected 


■ SSA 


8-bit: SSA 


area 




7-bit: ESC F 


find selected 


ESA 


8-bit: KSA 


area ' ■ 




7-bit: ESC G 


Set transmit 


DECTTC 


Normal 


termination 




CSI Ps | 


character 




Ps = end-of-block character. 

= no character. (D) 

1 = FF (form feed). 

2 = ETX (end of text). 

3 = EOT (end of transmission) 

4 - CR (carriage retui a). 

5 = DC3 (XOFFI. 



Extended 

CSI ? Pn I;...; Pn6 | 

Pnl:...:Pn6 = decimal code of end-of-block 

character(s). 



ID) = default. 



LOCAL EDITING 157 



Table 9-3 


Local Editing Sequences Summary (Cont) 


Name 


Mnemonic 


Sequence 


Transmit lir.p 


DECTLTC 


CSI?Pnl;...;Pn6's 


termination 
characters 




Pnl:...;Pn6 = decimal code of 
end-of-line characterise 
Default = carriage return (CR) 


Space 


DECSCFDM 


Set: CSI ? 13 h 


compression 
mode 




No spaces. 

Reset: CSI ? 13 1 
Spaces. (D) 


Transmit . 


DECTEM 


Set: CSI? 14 h 


execution 
mode 




Immediate. (I)) 

Reset: CSI? 141 
Deferred. 


Set transmit 


STS 


ESCS 


state 




From VT300. 


Transmit 


DECXMIT 


ESCS 

From host. .:';■/■"■ 


ID) = default. 







158 LOCAL EDITING 



CURSOR MOVEMENT AND PANNING 



10 



The Cursor, 161 

Text Cursor Enable Mode (DECTCEM), 161 
Moving the Cursor on the Current Page, 161 
Cursor Position (CUP), 162 
Horizontal and Vertical Position (HVP), 162 
Cursor Forward (CUF), 162 
Cursor Backward (CUB), 162 
Cursor Up (CUP), 162 
Cursor Down (CUD), 163 
Panning, 163 

Pan Down (SU), 163 
Pan Up (SD), 163 
Pan Right (SL), 164 
Pan Left (SR), 164 
Cursor Coupling, 164 

Horizontal Cursor Coupling Mode (DECHCCM), 165 
Vertical Cursor Coupling Mode (DECVCCM), 165 
Page Cursor Coupling Mode (DECPCCM), 166 
Summary, 167 



This chapter describes the control functions you use to move the cursor and 
view different areas in the terminal's page memory. Chapter 6 describes page 
memory. 



159 



Before you read this chapter, you should understand the difference between 
scrolling and panning. 

Scrolling is the movement of data between the margins of a page. Data 
scrolled beyond the margins is lost from page memory. Data is not lost 
from the host system's memory. 

Panning is the movement of the user window in page memory to view 
different parts of a page. You do not lose data in page memory, because 
the window moves rather than the data. You only use panning functions 
when the page you are viewing is larger than the user window. 

For example, suppose the current page is 72 lines x 80 columns. You can 
only display 24 lines of the page on the screen. To view other parts of the 
page, you can pan the user window up or down. 

Figure 10-1 shows the difference between scrolling and panning. 



SCROLLING 









BBBBBBBBBBB 






BBBBBBBBBBB 






BBBBBBBBBBB 






BBBBBBBBBBB 






BBBBBBBBBBB 






BBBBBBBBBBB 






BBBBBBBBBBB 


/ 







AAAAAAAAAA 

AAAAAAAAAA 
AAAAAAAAAA 
AAAAAAAAAA 
A A A AAA A A A A 
AAAAAAAAAA 
AAAAAAAAAA 
BBBBBBBBBBB 
BBBBBBBBBBB 



BBBBBBBBB 
BBBBBBBBB 



AFTER SCROLLING UP 




AAAAAAAAAA 

AAAAAAAAAA 
BBBBBBBBBBB 
BBBBBBBBBBB 
BBB8BBBBBBB 
BBBBBBBBBBB 



BBBBBBBBBBB 

ccccccccccc 
ccccccccccc 
ccccccccccc 

DDDDDDDDDD 
DDDDDDDDDD 



DATA SCROLLED PAST 
TOP MARGIN IS 
LOST FROM PAGE 
MEMORY 



DATA 
' ADDED 



PAGE 



PANNING 




USER 

WINDOW 



A A A A 
A A A A 
A A A A 
AAA A 
A A A A 
A A A A 
A A A A 
B B B B E 



V A A A A A 
\ A A A A A 
\ A A A A A 
IAAAAA 
UAAAA 
\ A A A A A 
\ A A A A A 



BBBBBBBBBBB 



BBBBBBBBBBB 



B BBBE 
BBBBE 

BBBBE 



AFTER PANNING DOWN 




A A AAA A A 
A A A A A A A 
AAA AAA A 
A AAA A A A 



A A A A A A A 
A A AAA A A 
A AAA A A A 
B B B B B B B 
BB BB BB B 
B BBB B B B 
B B B B 8B B 



BBBBBBBBBB 

BBBBBBBBBB 



DATA IS NOT 
LOST FROM 
PAGE MEMORY, 
BECAUSE DATA 
DOES NOT 
MOVE ON PAGE. 



- PAGE MUST BE LARGER THAN 24 LINES 



Figure 10-1 The Difference Between Scrolling and Panning 



160 CURSOR MOVEMENT AND PANNING 



A user window is the display area that lets you view data in page memory. The 
default user window for the VT300 is the complete screen (24 lines x 80 or 
132 columns). You can also divide the screen into two user windows, to view 
data from two sessions at the same time. Chapter 8 of Installing and Using 
the VT330/VT340 Video Terminal describes how to use windows. Also see 
Chapter 14 of this manual for more details on dual sessions. 

This chapter covers the control functions you use to move the cursor on a page 
and pan the user window across a page or pages. 

THE CURSOR 

The cursor is a marker that indicates the active position in page memory. The 
active position is the point on the current page where the next character is 
written. 

The default text cursor style is a blinking box. The cursor can also be a steady 
box, a blinking underscore, or a steady underscore. The user can select one of 
these cursor styles in the Display Set-Up screen. See Chapter 5 of Installing 
and Using the VT330/VT340 Video Terminal for details. 

Usually, the cursor appears on the screen. However, you can use control func- 
tions to move the cursor anywhere on the current page, or to any other page in 
page memory. 

Text Cursor Enable Mode (DECTCEM) 

This control function makes the cursor visible or invisible. 

Default: Visible 

Action 

Makes the cursor visible 
if the active position is on 
the screen. 

Makes the cursor invisible. 



MOVING THE CURSOR ON THE CURRENT PAGE 

This section describes the control functions you can use to move the cursor on 
the current page. Remember, page and display are two different concepts. The 
area of the main display is restricted to the screen — 24 lines by 80 or 132 
columns. The area of the current page can be 24, 36, 72 or 144 lines by 80 or 
132 columns, depending on the page format you select (Chapter 6). 

CURSOR MOVEMENT AND PANNING 161 



Mode 


Sequence 








Set 
(Visible) 


CSI ? 

9/11 3/15 


2 

3/2 


5 

3/5 


h 

6/8 


Reset 
(Invisible) 


CSI ? 

9/11 3/15 


2 

3/2 


5 

3/5 


1 

6/12 



NOTE: Some CO and Cl control characters not covered in this chapter also 
move the cursor. See Chapter 2 for detailed descriptions of these control 
characters. 

In the following sequences, the parameters Pn, PI, and Pc indicate cursor posi- 
tion. If you omit a parameter or use a value of 0, the terminal uses a default 
value of 1. 



Name 



Sequence 



Action 



Cursor 

position 

(CUP) 



CSI PI ; Pc H 

9/11 3/? 3/11 3/? 4/8 



Horizontal 
and vertical 
position (HVP) 



CSI PI ; Pc f 

9/11 3/? 3/11 3/? 6/6 



Cursor 


CSI 


Pn 


C 


forward 


9/11 


3/? 


4/3 


(CUF) 








Cursor 


CSI 


Pn 


D 


backward 


9/11 


3/? 


4/4 


(CUB) 








Cursor up 


CSI 


Pn 


A 


(CUU) 


9/11 


3/? 


4/1 



Moves the cursor to line 
PI, column Pc. The 
starting point for lines 
and columns depends on the 
setting of origin mode 
(DECOM). CUP applies only 
to the current page. 

If PI is or 1, the 
cursor moves to the first 
line of the page. If Pc is 
or 1, the cursor moves 
to the first column of the 
page. 

Works the same as CUP. 
New applications should 
use CUP instead of HVP. 
HVP is provided for 
compatibility with earlier 
Digital products. 

Moves the cursor right Pn 
columns. The cursor stops 
at the right border of the 
page border. 

Moves the cursor left Pn 
columns. The cursor stops 
at the left border of the 
page. 

Moves the cursor up Pn 
lines in the same column. 
The cursor stops at the 



162 CURSOR MOVEMENT AND PANNING 



Cursor down 
(CUD) 



CSI 

9/11 



Pn B 

3/? 4/2 



top margin. If the 
cursor is already above 
the top margin, the cursor 
stops at the top line. 

Moves the cursor down Pn 
lines in the same column. 
The cursor stops at the 
bottom margin. If the 
cursor is already below 
the bottom margin, the 
cursor stops at the bottom 
line. 



PANNING 

You can display any part of the current page by moving the user window 
across the page. The following control functions let you pan the user window up 
or down, left or right. To a user viewing the screen, data appears to scroll in 
the opposite direction. For example, if you pan up, the data appears to scroll 
down. 

In the following sequences, Pn indicates the cursor position. If you omit Pn or 
use a value of 0, the terminal uses a default value of 1. The term current page 
refers to the page with the cursor. 

NOTE: The ANSI mnemonics in parentheses are provided only for reference. 
These mnemonics do not indicate how the VT300 uses the panning functions. 
For example, the ANSI mnemonic for pan down is SU (scroll up). 



Name 

Pan down 

(SU) 



Sequence 

CSI Pn S 

9/11 3/? 5/3 



Pan up 
(SD) 



CSI Pn T 

9/11 3/? 5/4 



Action 

Moves the user window 
down Pn lines in page 
memory. Pn new lines 
appear at the bottom of 
the display. Pn old lines 
disappear at the top of 
the display. You cannot 
pan past the bottom margin 
of the current page. 

Moves the user window 
up Pn lines in page 



CURSOR MOVEMENT AND PANNING 163 



memory. Pn new lines 
appear at the top of 
the display. Pn old lines 
disappear at the bottom of 
the display. You cannot 
pan past the top 
margin of the current 
page. 

Pan right CSI Pn sp @ Moves the user window 

(SL) 9/11 3/? 2/0 4/0 right Pn columns in page 

memory. Pn new columns 
appear at the right of the 
display. Pn old columns 
disappear at the left of 
the display. You cannot 
pan past the right page 
border. 

Pan left CSI Pn sp A Moves the user window 

(SR) 9/11 3/? 2/0 4/1 left Pn columns in page 

memory. Pn new columns 
appear at the left of the 
display. Pn old columns 
disappear at the right of 
the display. You cannot 
pan past the left page 
border. 

CURSOR COUPLING 

This section describes control functions that make the user window pan with 
the cursor when the cursor moves past the window boundaries. These functions 
are called cursor coupling modes. 

A coupled cursor is a cursor that appears to pull the user window through the 
page. When an application tries to write data beyond the borders of the user 
window, it pans in that direction to keep the cursor visible in the display. The 
cursor looks like it is connected, or coupled, to the display. 

You can have applications set the coupling modes to cause automatic panning. 
You can also reset the coupling modes to write data into off-screen page 
memory. 



164 CURSOR MOVEMENT AND PANNING 



Horizontal Cursor Coupling Mode (DECHCCM) 

This control function determines whether the user window pans with the cursor 
when the cursor moves past the left or right border of the window. DECHCCM 
is only useful when the width of the current user window is narrower than the 
page. The cursor must stay on the current page. 

Default: Uncoupled 



Mode 



Sequence 



Action 



Set 
(Coupled) 



CSI ? 6 h 

9/11 3/15 3/6 3/0 6/8 



Reset 
(Uncoupled) 



CSI ? 6 1 

9/11 3/15 3/6 3/0 6/12 



Couples the cursor to the 
display for horizontal 
movement. When the cursor 
tries to move past the 
left or right border of 
the user window, the 
window pans to keep the 
cursor in view. 

If the cursor tries to 
move past the left border 
of the user window, the 
window pans left. New 
columns appear at the 
left, while columns at the 
right move out of view. 

Uncouples the cursor from 
the display, for 
horizontal movement. If 
the cursor moves past the 
left or right border of 
the user window, the 
cursor disappears. 



Vertical Cursor Coupling Mode (DECVCCM) 

This control function determines whether the user window pans with the cursor 
when the cursor moves past the top or bottom border of the user window. 
DECVCCM is only useful when the height of the current user window is 
smaller than the page. The cursor must stay on the current page. 



CURSOR MOVEMENT AND PANNING 165 



Default: Coupled 

Mode Sequence 



Set 
(Coupled) 



CSI ? 6 1 h 

9/11 3/15 3/6 3/1 6/8 



Reset 
(Uncoupled) 



CSI ? 6 11 

9/11 3/15 3/6 3/1 6/12 



Action 

Couples the cursor to the 
display for vertical 
movement. If the cursor 
tries to move past the top 
or bottom border of the 
user window, the window 
pans to keep the cursor in 
view. 

If the cursor tries to 
move past the top of the 
display, the user window 
pans up. New lines appear 
at the top of the screen, 
while lines at the bottom 
move out of view. 

Uncouples the cursor from 
the display. If the 
cursor moves past the top 
or bottom border of the 
user window, the cursor 
disappears. 

Page Cursor Coupling Mode (DECPCCM) 

This control function determines if a new page appears in the display when the 
cursor moves to a new page. DECPCCM is only useful with a multiple-page 
format (Chapter 6). 



Action 

Couples the cursor to the 
display when the cursor 
moves to a new page. The 
new page appears in the 
display to keep the cursor 
visible. 



Default: Coupled 




Mode 


Sequence 


Set 


CSI ? 6 4 h 


(Coupled) 


9/11 3/15 3/6 3/4 6/8 



166 CURSOR MOVEMENT AND PANNING 



Reset CSI ? 6 4 1 

(Uncoupled! 9/11 3/15 3/6 3/4 6/12 



Uncouples the cursor from 
the display. If the cursor 
moves to a new page, the 
cursor disappears. 



SUMMARY 

Table 10-1 lists the control functions described in this chapter. 

Table 10-1 Cursor Movement and Panning Sequences 



Name Mnemonic 

Enabling the Cursor 

Text cursor DECTCEM 

enable mode 



Sequence 



Set: CSI ? 25 h 
Visible cursor. (D) 

Reset: CSI ? 25 1 
Invisible cursor. 



Moving the Cursor* 



Cursor 
position 

Horizontal 
and vertical 
position 

Cursor 
forward 

Cursor 

backward 

Cursor up 
Cursor down 



CUP 



HVP 



CUF 



CUB 



CUT) 



CUD 



CSI PI : P( H 

Line PI, column Pc. 

CSI PI ; Pc f 

Line PI. column Pc. 
(Recommend use of CUP. 

CSI Pn C 

Pn columns right. 

CSI Pn D 

Pn columns left. 

CSI Pn A 

Pn lines up. 

CSI Pn B 

Pn lines down. 



(D) = default. 

* In these sequences, the default value for Pn. PI. and Pc is 1. 



CURSOR MOVEMENT AND PANNING 167 



Table 10-1 Cursor Movement 


and Punning Si-quenc 


Name : : 


Mnemonic 


Sequence 


Panning* 






Pan down 


SU 


CSI Pn S 

Pn lines down. 


Pan. up 


SD 


CSI Pn T 

Pn lines up. 


Pan right 


SL 


CSI Pn sp @ 

Pn columns right 


Pan left 


SR 


CSI Pn sp A 

Pn columns left. 


Horizontal 


DECHCCM 


Set: CSI ? 60 h 


cursor 




Coupled 


coupling mode 




Reset: CSI ? 60 1 
Uncoupled (D) 


Vertical 


DECVCCM 


Set: CSI ? 61 h 


cursor 




Coupled IDI 


coupling mode 




Reset: CSI ? 61 1 

Uncoupled 


Pago cursor 


DECPCCM 


Set: CSI ? 04 h 


coupling mode 




Coupled (D> 

Reset: CSI ? 64 1 
Uncoupled 



<D) = default. 

* In these sequences, the default value for Pn is 1. 



168 CURSOR MOVEMENT AND PANNING 



KEYBOARD, PRINTING, 
AND DISPLAY COMMANDS 



11 



Keyboard Control Functions, 170 

Keyboard Action Mode (KAM), 170 
Backarrow Key Mode (DECBKM), 170 
Line Feed/New Line Mode (LNM), 171 
Autorepeat Mode (DECARM), 172 
Autowrap Mode (DECAWM), 172 
Cursor Keys Mode (DECCKM), 173 
Numeric Keypad, 173 

Keypad Numeric and Application Modes (DECKPAM and DECKPNM), 

173 

Numeric Keypad Mode (DECNKM). 174 
Typewriter or Data Processing Keys, 174 

Keyboard Usage Mode (DECKBUM), 175 
User-Defined Keys (DECUDK), 175 
Using UDKs, 176 
UDK Memory Space, 176 
Programming UDKs, 176 
Printer Port Control Functions, 181 

Printer Extent Mode (DECPEX), 181 
Print Form Feed Mode (DECPFF), 181 
Printing Functions, 182 

Printing a Display Line: Autoprint Mode, 183 
Sending Characters Directly to the Printer: Printer 

Controller Mode, 183 
Print Page, 183 

Print Composed Main Display, 184 
Print All Pages, 184 
Print Cursor Line, 184 



169 



Start Printer-to-Host Session, 184 

Stop Printer-to-Host Session, 184 

Assign Printer to Active Host Session, 185 

Release Printer, 185 
Printing Visual Attributes, 185 

Sending Line Attributes, 185 

Sending Visual Character Attributes, 186 
Screen Display Control Functions, 186 

Local Echo: Send/Receive Mode (SRM), 186 

Light or Dark Screen: Screen Mode (DECSCNM), 187 

Scrolling Mode (DECSCLM), 187 

Selecting the Indicator or Host Status Line, 188 
Select Active Status Display (DECSASD), 189 
Select Status Display Type (DECSSDT), 189 
Summary, 190 



KEYBOARD CONTROL FUNCTIONS 

This section describes control functions that affect keyboard operation. 

Keyboard Action Mode (KAM) 

This control function locks or unlocks the keyboard. 

Default: Unlocked 

Mode Sequence Action 

Set CSI 2 h Locks the keyboard. The 

(Locked) 9/11 3/2 6/8 keyboard cannot send characters 

to the host. The Wait indicator 
comes on. The terminal ignores 
all keystrokes that send 
characters to the host. KAM 
does not affect the Set-Up 
or Switch Session keys. 



Reset 


CSI 2 


1 


Unlocks the keyboard. The 


(Unlocked) 


9/11 3/2 


6/12 


keyboard can send characters to 
the host. 



Backarrow Key Mode (DECBKM) 

This control function determines whether the <x] key works as a backspace 
key or delete key. 

170 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



NOTE: For compatibility with Digital's software, you should keep DECBKM 
reset (DEL). 



Default: Delete key 

Mode Sequence 



Set 
(BS) 



Reset 
(DEL) 



CSI ? 6 7 h 

9/11 3/15 3/6 3/7 6/8 



CSI ? 6 7 1 

9/11 3/15 3/6 3/7 6/12 



Action 

The < x] key works as a 
backspace key. When you 
press <x], the terminal 
sends a BS character to 
the host. 

The < x] key works as a 
delete key. When you 
press <x], the terminal 
sends a DEL character to 
the host. 



Notes on DECBKM 

• In edit mode, DECBKM is always reset (DEL). 

Line Feed/New Line Mode (LNM) 

This control function selects the characters sent to the host when you press 
the Return key. LNM also controls how the terminal interprets line feed (LF), 
form feed (FF), and vertical tab (VT) characters. 

NOTE: For compatibility with Digitals software, you should keep LNM reset 
(line feed). 



Default: Line feed 



Mode 

Set 
(New line) 



Sequence 

CSI 2 h 

9/11 3/2 3/0 6/8 



Action 

When the terminal receives 
an LF, FF, or VT 
character, the cursor 
moves to the first column 
of the next line. 

When you press Return, the 
terminal sends both a 
carriage return (CR) and 
line feed (LF). 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 171 



Reset 
(Line feed) 



CSI 2 1 

9/11 3/2 3/0 6/12 



When the terminal receives 
an LF, FF, or VT 
character, the cursor 
moves to the current 
column of the next line. 

When you press Return, the 
terminal sends a CR only. 



Notes on LNM 



• When the auxiliary keypad is in keypad numeric mode (DECKPNM), 
the Enter key sends the same character(s) as the Return key. 

Autorepeat Mode (DECARM) 

This control function determines whether or not keys automatically repeat their 
character when held down. If DECARM is set, most keys you press for more 
than 0.5 seconds send a character repeatedly until you release the key. 



Default: Repeat 

Mode Sequence 



Action 



Set 


CSI 


? 8 


h 


(Repeat) 


9/11 


3/15 3/8 


6/8 


Reset 


CSI 


? 8 


1 


(No repeat) 


9/11 


3/15 3/8 


6/8 



Keys autorepeat when 
pressed for more than 
0.5 seconds. 

Keys do not autorepeat. 



Notes on DECARM 

• The following keys never repeat: Hold Session, Local Print, Switch 
Session, Break, Return, Compose Character, Lock, Shift, and Ctrl. 

Autowrap Mode (DECAWM) 

This control function determines whether or not received characters automati- 
cally wrap to the next line when the cursor reaches the right border of a page 
in page memory. 



172 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Default: No autowrap 
Mode Sequence 



Set 
(Autowrap) 



CSI ? 7 h 

9/11 3/15 3/7 6/8 



Action 

Selects autowrap. Graphic 
characters received when 
the cursor is at the right 
border of the page appear 
at the beginning of the 
next line. Any text on the 
page scrolls up if the 
cursor is at the end 
of the scrolling region. 

Turns off autowrap. 
Graphic characters 
received when the cursor 
is at the right border 
of the page replace 
characters already on 
the page. 



Cursor Keys Mode (DECCKM) 

This control function selects the sequences the arrow keys send. You can use 
the four arrow keys to move the cursor through the current page or to send 
special application commands. See Chapter 3 for the sequences the keys send. 



Reset 

(No autowrap) 



CSI ? 7 1 

9/11 3/15 3/7 6/12 



Default: Cursor 

Mode Sequence 



Set 
(Application) 

Reset 
(Cursor) 



CSI ? 1 h 

9/11 3/15 3/1 6/8 

CSI ? 11 

9/11 3/15 3/1 6/12 



Action 

Arrow keys send 
application sequences to 
the host. 

Arrow keys send ANSI 
cursor sequences to the 
host. 



Numeric Keypad 

The following control functions are for the numeric keypad. The keypad applica- 
tion and numeric modes (DECKPAM and DECKPNM) work the same as nu- 
meric keypad mode (DECNKM). See Chapter 3 for the sequences the keys 
send. 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 173 



Keypad Application and Numeric Modes (DECKPAM and DECKPNM) - These 
control functions select whether the numeric keypad sends numeric characters 
or application sequences to the host. 



Default: Numeric characters 
Mode Sequence 



Application 
(DECKPAM) 

Numeric 
(DECKPNM) 



ESC = 

1/11 3/13 

ESC > 

1/11 3/14 



Action 

Numeric keypad sends 
application sequences. 

Numeric keypad sends the 
characters shown on the 
key (number, comma, 
period, or minus sign). 
Keys PF1 through PF4 send 
application sequences. 



Notes on DECKPAM and DECKPNM 



• When you turn on or reset the terminal, the terminal automatically 

selects numeric keypad mode. 

Numeric Keypad Mode (DECNKM) - This control function selects whether the 
numeric keypad sends numeric characters or application sequences to the host. 

Available in: VT300 mode only 
Default: Numeric 



Mode 

Set 
(Application) 

Reset 
(Numeric) 



Sequence 

CSI ? 6 6 h 

9/11 3/15 3/6 3/6 6/8 

CSI ? 6 6 1 

9/11 3/15 3/6 3/6 6/12 



Action 

Numeric keypad sends 
application sequences. 

Numeric keypad sends the 
characters shown on the 
key (number, comma, 
period, or minus sign). 
Keys PF1 through PF4 send 
control functions. 



Notes on DECNKM 



DECNKM is provided mainly for use with the request and report 
mode (DECRQM/DECRPM) control functions (Chapter 12). 



174 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Typewriter or Data Processing Keys 

You can select whether the main keyboard keys act as data processing keys or 
typewriter keys. See Chapter 3 for a description of data processing keys. 

Keyboard Usage Mode (DECKBUM) 

Default: Typewriter keys 

Mode Sequence Action 



Set 

(Data 

processing) 

Reset 
(Typewriter) 



CSI ? 6 8 h 

9/11 3/15 3/6 3/8 6/8 



CSI ? 6 8 1 
9/11 3/15 3/6 3/8 6/12 



Selects data processing 
keys. The terminal sends 
the characters on the 
right half of the keycaps. 

Selects typewriter keys. 
The terminal sends the 
characters on the left 
half of the keycaps. 



Notes on DECKBUM 

• DECKBUM changes the characters that the main keyboard keys 
send. Make sure you are aware of this change if you use 
DECKBUM in an application. 

• If you use the North American dialect, DECKBUM should always be 
reset (typewriter). For all other languages, you can use either mode. 

USER-DEFINED KEYS (DECUDK) 

The keyboard has 20 function keys on its top row. You can define the codes of 
15 of these top-row keys. 



F6 through F14 

Do 

Help 

F17 through F20 



The other five keys — Hold Session, Local Print, Set-Up, Switch Session, and 
Break — have dedicated local functions and are not definable. 

User-defined keys (UDKs) are only available in VT300 mode. UDKs do not 
work in VT100 and VT52 modes. 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 175 



Using UDKs 

There are two ways to enter definitions for the 15 UDKs. 

• Type in the definitions by using the UDK Set-Up screen. See 
Chapter 7 of Installing and Using the VT330/VT340 Video Terminal. 

• Program the definitions with DECUDK device control strings. 

This chapter describes how to program the keys using a DECUDK device con- 
trol string. 

After you define a key, you can use the new function by pressing Shift- < key >, 
where < key > is the key you defined. 

UDK Memory Space 

There are 256 bytes of memory available for the 15 user-defined keys. Space is 
supplied on a first-come/first-serve basis. When the 256 bytes are full, you can- 
not define any more keys until you clear some of the memory space. There are 
five ways you can clear space. 

Redefine one or more UDKs by using the UDK Set-Up screen. 
Redefine one or more UDKs by using a DECUDK control string. 
Clear one or more UDKs by using a DECUDK control string. 
Clear one or more UDKs by using the UDK Set-Up screen. 
Clear all UDKs with a terminal power-up or reset (RIS) operation. 

Programming UDKs 

You use the following device control string format to down-line-load definitions 
for user-defined keys. See Chapter 2 for general information about device con- 
trol strings. 

DECUDK Device Control String Format 

Available in: VT300 mode only 

DCS Pc;Pl | Kyl/Stl;...Kyn/Stn ST 

Key Definition String String 

Terminator 



Device 


Clear 


Final 


Control 


and Lock 


Character 


String 


Parameters 




Introducer 







176 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



where 



DCS (9/0) 

indicates the beginning of a device control string. DCS is an 8-bit 
CI character. You can use ESC P (1/11 5/0) for a 7-bit environment. 



Pc 



is the clear parameter, Pc selects how to clear key definitions. 

Pc Action 

(default) Clear all keys before loading new values, 
or none 

1 Clear one key at a time, before loading a new 
value. 

When Pc is 1, the terminal only clears the keys you are loading. By 
using a Pc value of 1, you can redefine some keys without redefining 
them all. 

NOTE: There are 256 bytes of memory for all user-defined keys. A 
key definition can only use the number of bytes available when that 
key is loaded. 

PROGRAMMING TIP: If Pc is 1, a key load may fail because no 
memory space is available. The reason for this is as follows. 

With Pc set to 1, keys are cleared and loaded sequentially. If the 
new definition for a key is larger than the old one, you may exceed 
the 256 byte limit. 

For example, suppose F6 contains 120 bytes, F7 contains 110 bytes, 
and F8 contains 20 bytes. You try to load F8 with 40 bytes, F6 with 
1 byte, and F7 with 1 byte, in that order. This works if all keys are 
cleared first (Pc is 0), but not if keys are cleared one at a time (Pc is 
1). When you try to load F8 with 40 bytes, the load fails because 
only 26 bytes are free at that time. 

256 (maximum) - 120 (in F6) - 110 (in F7) = 26 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 177 



PI 

is the lock parameter. PI determines whether the key definitions are 
locked or unlocked after you load them. 

PI Action 

or none Lock the keys. If you want to load new 

values into the keys, you must unlock the 
keys by using set-up. 

1 (default) Do not lock the keys. The keys are 

unlocked and can be redefined with 
another DECUDK string. 

NOTE: If PI is 1 and the keys are already locked, nothing happens, 

The terminal uses a special lock to allow or prevent the program- 
ming of user-defined keys. You can turn on this lock from set-up or 
from the host (with a DECUDK device control string). The lock af- 
fects all programmable keys. When you use the lock, you should fol- 
lowing these guidelines. 

• Unlock the keys to define them. 

The keys must be unlocked before you can define them. You can 
only unlock the keys from set-up. If a key is locked and an appli- 
cation tries to redefine the key with a DECUDK sequence, the 
terminal ignores the sequence. 

• Lock the keys to prevent redefinition. 

You can lock the keys from set-up or from the host (by sending 
a DECUDK sequence). New key definitions are locked by default. 



is the final character. The vertical bar (7/12) identifies this control 
string as a DECUDK. 

Kyl/Stl;...Kyn/Stn 

are the key definition strings. You include these strings between the 
final character (|) and the string terminator (ST). Each string con- 
sists of a key selector number (Kyn) and a string parameter (Stn), 
separated by a slash (/, 2/15). A semicolon (3/11) separates different 
strings. 

• The key selector number (Kyn) indicates which key you are de- 
fining. Here is a list of definable keys and their identifying 
values. 

178 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Key Value Key Value 



ST 



F6 


17 


Help 


28 


F7 


18 


Do 


29 


F8 


19 


F17 


31 


F9 


20 


F18 


32 


F10 


21 


F19 


33 






F20 


34 


Fll 


23 






F12 


24 






F13 


25 






F14 


26 







The string parameters (Stn) are the encoded definition of the 
keys. String parameters consist of hex pairs in the following 
ranges. 

3/0 through 3/9 (0 through 9) 
4/1 through 4/6 (A through F) 
6/1 through 6/6 (a through f) 

When you combine these hex values, they represent an 8 -bit 
quantity. The ASCII table in Chapter 2 lists the hex values of 
characters. 

This method lets you use any of the 256 character codes in the 
key string. You can enter key definition strings in any order. 

Default: Empty. The key is undefined. 



is the string terminator. ST (9/12) is a Cl 8-bit character. You can 
use ESC \ (1/11, 5/12) for a 7-bit environment. 



Notes On Loading UDKs 

Here are some general guidelines you should keep in mind when loading UDKs. 

• Clear UDK memory space before loading new definitions- 
Use a DECUDK string to clear keys without locking them. Then 
you can use another DECUDK string to redefine the keys and lock 
them. 

• If you redefine a key, the old definition is lost. 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 179 



This may clear some space if the new definition uses less bytes than 
the old one. 

• There are two ways to lock UDKs, but only one way to unlock them. 

To lock UDKs, you can use the UDK Set-Up screen or a DECUDK 
control string. To unlock UDKs, you must use the UDK Set-Up 
screen. 

• The default value for each key definition is empty. 
When you clear UDKs, they are empty. 

• You can save UDK definitions by using the UDK Set-Up screen. 

See Chapter 7 of Installing and Using the VT330/VT340 Video 
Terminal for details. 

• An invalid hex pair in a DECUDK string stops a UDK load 
sequence. 

When a load sequence stops (due to error or other cause), the termi- 
nal saves any keys already loaded and sends the rest of the 
DECUDK sequence to the screen. 

Examples of DECUDK Device Control Strings 

• The following sequence clears UDKs. 

DCS ; 1 | ST 

• The following sequence locks UDKs. 

DCS 1 ; | ST 

• Suppose you want to define the F20 key to be "PRINT", without 
clearing or locking any other keys. The first part of your sequence 
would look like this. 

DCS 1 ; 1 | 3 4 / 

where 34 is the code for the F20 key. 

After the slash character (2/15), you include the definition. The rest 

180 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



of the sequence after the slash character would look like this. 

5052494E54ST 

where the hex encoding for "PRINT" is as follows. 

50 = P 

52 = R 

49 = I 

4E = N 

54 = T 

The ST character (9/12) marks the end of the control 
string. 

The complete string is as follows. 

DCS 1 ; 1 | 34 / 50 52 49 4E 54 ST 

PRINTER PORT CONTROL FUNCTIONS 

This section describes control functions you use to control a local printer. 

Printer Extent Mode (DECPEX) 

This control function selects how much data you can print when you use the 
print page function described in the next section. 

Default: Scrolling region 



Mode 

Set 
(Page) 

Reset 

(Scrolling 

region) 



Sequence 

CSI ? 19 

9/11 3/15 3/1 3/9 

CSI ? 19 

9/11 3/15 3/1 3/9 



h 

6/8 

1 
6/12 



Action 

The print page function 
prints the complete page. 

The print page function 
only prints the scrolling 
region (data inside the 
margins). 



Print Form Feed Mode (DECPFF) 

This control function selects whether or not the terminal sends a form feed 
(FF) character to the printer at the end of a printing function. 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 181 



Default: No form feed 
Mode Sequence 

Set CSI ? 1 8 h 

(Formfeed) 9/11 3/15 3/1 3/8 6/8 



Reset CSI ? 18 1 

(No form feed) 9/11 3/15 3/1 3/8 6/12 



Action 

The terminal sends a form 
feed (FF) to the printer 
at the end of a printing 
function. 

The terminal sends nothing 
to the printer at the end 
of a printing function. 



Notes on DECPFF 



• DECPFF does not affect the print cursor line function described in 
the next section. 

PRINTING FUNCTIONS 

This section describes control functions you use to print text from the terminal. 
If you do not have a printer connected to the terminal, the terminal ignores 
these functions. 

When you print characters from the screen or current page, the printer con- 
verts all tabs to spaces. Printed characters are spaced with the space <SP) char- 
acter. The terminal sends a carriage return (CR), line feed (LF), vertical tab 
(VT), or form feed (FF) character to the printer after the last printed character 
on a line. 

All the printing functions described in this section are variations of the media 
copy (MC) command. There are two versions of the MC command, standard 
and DEC private. The format of each version is as follows. 



MC ANSI standard 



MC DEC private 



CSI 


Ps 


i 




9/11 


3/? 


6/9 




CSI 


? 


Ps 


i 


9/11 


3/15 


3/? 


6/9 


wher€ 


i 






Ps indicates the function of the command 



182 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Printing a Display Line: Autoprint Mode 

In this mode, the printer prints a line from the screen when you move the 
cursor off that line with an LF, FF, or VT character, or an autowrap occurs. 
The printed line ends with a CR and the character (LF, FF, or VT) that moved 
the cursor off the previous line. 

Sequence Action 

CSI ? 5 i Turns on autoprint mode. 

CSI ? 4 i Turns off autoprint mode. 

Sending Characters Directly to the Printer: 
Printer Controller Mode 

In this mode, the terminal sends received characters to the printer without dis- 
playing them on the screen. The terminal sends all characters and control se- 
quences to the printer, except NUL, XON, XOFF, and the printer controller 
mode sequences. 

Sequence Action 

CSI 5 i Turns on printer controller mode. 

CSI 4 i Turns off printer controller mode. 

Notes on Printer Controller Mode 

• Printer controller mode cancels autoprint mode. When the terminal 
leaves printer controller mode, the terminal returns to the normal 
method for printing operations. 

• The printer's active column position should always be on the left 
margin before the terminal leaves printer controller mode. 

Print Page 

This control function prints the page that has the cursor. The terminal stores 

data from the keyboard until printing is complete. 

You can use either of the following sequences to print the page. 

CSI i or CSI i 

Notes on Print Page 

• If printer extent mode (DECPEX) is currently reset, the print page 
function only prints the scrolling region. 

KEYBOARD, PRINTING, AND DISPLAY COMMANDS 183 



Print Composed Main Display 

This control function prints the data on the screen. This data may include in- 
formation from two sessions, if the screen is displaying data from both ses- 
sions. See Chapter 14 for information of dual sessions. 

CSI ? 10 i 
Notes on Print Composed Main Display 

• Printer extent mode (DECPEX) does not affect this function. 

Print All Pages 

This control function prints all pages in page memory for the current session. 
For example, if the current page format is 3 pages of 24 lines each, the printer 
prints 3 pages of 24 lines. The terminal stores new data from the keyboard 
until printing is complete. 

CSI ? 11 i 
Notes on Print All Pages 

• If print form feed mode (DECPFF) is set, the terminal sends a form 
feed (FF) to the printer after each page. 

Print Cursor Line 

This control function prints the line that has the cursor. The cursor does not 
move. 

CSI ? 1 i 
Start Printer-to-Host Session 

This control function enables communication from the printer port to the active 
host session. See Chapter 14 for details on session management. 

CSI ? 9 i 

Stop Printer-to-Host Session 

This control function disables communication from the printer port to the ac- 
tive host session. See Chapter 14 for details on session management. 

CSI ? 8 i 



184 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Assign Printer to Active Host Session 

This control function lets the terminal accept printer commands from the cur- 
rent session only . See Chapter 14 for details on session management. 

Software should use a device status report (DSR) to ask if the printer is not 
assigned to the other session. If the inactive session sends a DSR while the 
printer is assigned to the active session, the inactive session receives a "printer 
assigned" message. See Chapter 12 for details on DSR reports. 

CSI ? 18 i 

Release Printer 

This control function lets the terminal accept printer commands from both ses- 
sions. See Chapter 14 for details on session management. 

CSI ? 19 i 

PRINTING VISUAL ATTRIBUTES 

This section describes how the terminal sends visual attributes to a local 
printer, such as bold or underlining. To send visual attributes, the Printed Data 
Type feature in the Printer Set-Up screen must be set to one of the following 
three modes. 

national and line drawing 

multinational 

print all characters 

See Chapter 11 of Installing and Using the VT330/VT340 Video Terminal for 
details. 

The VT300 can send two types of visual attributes, line attributes and visual 
character attributes. 

Sending Line Attributes 

The terminal sends line attributes to a printer by (1) sending the appropriate 
line attribute control function, followed by (2) the characters in the current line. 
There are four line attribute control functions. 

Single-width line ESC # 5 

Double-width line ESC # 6 
Double-width/double-height line 

Top half ESC * 3 

Bottom half ESC # 4 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 185 



Sending Visual Character Attributes 

The terminal initializes character attributes at the beginning of each print line 
or print page operation by sending the following SGR sequence to the printer 
(Chapter 7). 

ESC [ m 

This sequence sets all character attributes to the normal rendition. 

To send a visual character attribute to a printer, the VT300 (1) sends the ap- 
propriate SGR sequence for that attribute, followed by (2) the current charac- 
ter. The SGR sequence is as follows. 

ESC[0;Ps;Ps;...Psin 

where 

Ps indicates a character attribute sent. 

Ps Attribute 

Normal (all attributes off) 

1 Bold 

2 Underline 
5 Blink 

7 Invisible 

NOTE: The terminal sends characters with the invisible attribute as spaces. 

After each print line or print page operation, the terminal clears all attributes 
by sending the following sequence. 

ESC [ m. 

SCREEN DISPLAY CONTROL FUNCTIONS 

This section describes control functions that affect how the terminal displays 
data. 

Local Echo: Send/Receive Mode (SRM) 

This control function turns local echo on or off. When local echo is on, the 
terminal sends keyboard characters to the screen. The host does not have to 
send (echo) the characters back to the terminal display. When local echo is off, 
the terminal only sends characters to the host. It is up to the host to echo 
characters back to the screen. 



186 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Default: No local echo 
Mode Sequence 



Set 

(No local 
echo) 



Reset 
(Local 
echo) 



CSI 1 2 h 

9/11 3/1 3/2 6/8 



CSI 1 2 1 

9/11 3/1 3/2 6/12 



Action 

Turns local echo off. The 
terminal sends keyboard 
characters to the host 
only. The host can echo 
the characters back to 
the screen. 

Turns local echo on. The 
terminal sends keyboard 
characters to the host and 
to the screen. The host 
does not have to echo 
characters back to the 
terminal. 



Light or Dark Screen: Screen Mode (DECSCNM) 

This control function selects a dark or light background on the screen. 

Default: Dark background 

Mode Sequence Action 



Set 

(Light 

background) 

Reset 
(Dark 
background) 



CSI ? 5 h 

9/11 3/15 3/5 6/8 



CSI ? 5 1 

9/11 3/15 3/5 6/12 



Selects reverse video. 
The screen displays dark 
characters on a light 
background. 

Selects a normal display. 
The screen displays light 
light characters on a dark 
background. 



Notes on DECSCNM 



• Screen mode only affects how the data appears on the screen. 

DECSCNM does not change the data in page memory. 

Scrolling Mode (DECSCLM) 

This control function selects the way the terminal scrolls lines. You can select 
one of two scroll settings, smooth or jump. 



KEYBOARD, PRINTING, AND DISPLAY COMMANDS 187 



Default: Smooth scroll 
Mode Sequence 



Set 
(Smooth) 



CSI ? 4 h 

9/11 3/15 3/4 6/8 



Display Set-Up. See 



Reset 
(Jump) 



CSI ? 4 1 

9/11 3/15 3/4 6/12 



Action 

Selects smooth scroll at 
a rate of 6 lines per 
second. You can select a 
smooth scroll speed of 3 
or 12 lines per second in 

Installing and Using the 
VT330/VT340 Video 
Terminal, Chapter 5. 

Selects jump scroll. 
The terminal can add lines 
to the screen as fast as 
it receives them. 



Notes on DECSCLM 



• If "no scroll" is selected in Display Set-Up, the terminal ignores 
DECSCLM. 

Selecting the Indicator or Host-Writable Status Line 

The twenty-fifth line at the bottom of the screen is reserved for the status line. 
The terminal lets you use the status line in two ways — as an indicator of the 
terminal's current state, or as a window the host can use to display application- 
specific messages. 

The indicator status line displays information about the current state of the 
terminal. This status line is enabled by default. It appears in reverse video 
(negative image) on the twenty-fifth screen line. This status line always appears 
in set-up. 

The indicator status line displays the following information about the terminal. 

• Active session number (1 or 2) 

• Page number 

• Text cursor position (line, column) or ReGIS graphics input position 
(pixel row, pixel column) 

• Edit mode setting (in edit mode only) 

• Insert/replace mode setting (in set-up and edit mode only) 

• Printer status 

• Modem status 



188 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



The host-writable status line can display specific information from the host. 
That is, you can program this status line to display any information you want. 
In a dual session environment, each session has its own host-writable status 
line. See Chapter 14 for more information on dual sessions. 

You can send data to the status line and select the type of status line with the 
following control sequences. 

Select Active Status Display (DECSASD) - This control function selects 
whether the terminal sends data to the main display or the status line. The 
main display is the first 24 lines on the screen. The status line is the twenty- 
fifth line. 

Available in: VT300 mode only 

Default: Main display 

CSI Ps $ } 
9/11 3/? 2/4 7/13 

where 

Ps represents the display the terminal sends data to, as follows. 

Ps Action 

(default) Selects the main display. The terminal sends data to 

the main display only. 

1 Selects the status line. The terminal sends data to the 
status line only. 

Select Status Line Type (DECSSDT) - This control function lets the host se- 
lect the type of status line displayed on line 25 of the screen. 

Available in: VT300 mode only 

Default: Indicator status line 

CSI Ps $ 

9/11 3/? 2/4 2/13 

where 

Ps indicates which status line the host selects, as follows. 

Ps Status Line Selected 

No status line (The 25th line is blank.) 

KEYBOARD, PRINTING, AND DISPLAY COMMANDS 189 



1 (default) 
2 

Notes on DECSSDT 



Indicator status line 
Host-writable status line 



If you change from an indicator to a host-writable status line, the 
new host-writable status line is empty. 

When you select the host-writable status line, most of the control 
functions that affect the main display also affect the status line. The 
following list describes the exceptions to the above rule. 



Control Function 

Select character set 
(SCS) 

Cursor position 
controls 



Action 

Both the main display and status line 
use the same character set. 

Only the column parameters in cursor 
positioning commands operate in the 
status line. 



ANSI mode (DECANM) Ignored if received in the status line. 

Set conformance level Exits status line. 
(DECSCL) 



Scrolling mode 
(DECSCLM) 

Soft terminal reset 
(DECSTR) 

Insert/replace mode 
(IRM) 

Hard terminal reset 
(RIS) 

Tab stops 

Auto wrap mode 
(DECAWM) 



Affects the main display and the 
status line. 

Exits status line. 



Affects the main display 
and the status line. 

Erases and exits the 
status line. 

Affect main display and status line. 

Affects main display and 
status line. 



• DECSSDT does not affect the status line type displayed in set-up. 

In set-up, the terminal always uses the indicator status line. 

SUMMARY 

Tables 11-1 through 11-4 list the control sequences described in this chapter. 



190 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Table 111 Keyboard Control Sequences 
Mode Mnemonic Sequence 

Set 



Reset 



Keyboard 
action mode 


KAM 


CSI 2 h 

Locked. 


CSI 2 ! 
Unlocked.lD) 


Backarrow key 
mode; 


DECBKM 


CSI ? 67 h 

Backspace. 


CSI ? 67 1 

Delete. ID! 


Line feed/ 
new line mode 


LNM 


CSI 20 h 

New line. 


CSI 20 1 

Line feed. ID) 


Autorepeat 
mode 


DEC ARM 


CSI ? 8 h 
Repeat. (Dl 


CSI ? 8 1 

No repeat. 


Autowrap 
mode 


DECAWM 


CSI ? 7 h 

Autowrap. 


CSI ? 7 1 

No autowrap. (D) 


Cursor keys 
mode 


DECCKM 


CSI ? 1 h 
Application. 


CSI ? 1 1 
Cursor. (D) 


Keypad 
application/ 
numeric modes 


DECKPAM 
DECKPNM 


ESC = 

Application. 


ESC > 

Numeric. (D) 


Numeric 
keypad mode 


DEC N KM 


CSI ? 66 h 

Application. 


CSI ? 66 1 

Numeric. (D) 


Keyboard 
usage mode 


DECKBUM 


CSI ? 68 h 
Data processing. 


CSI ? 68 1 
Typewriter. (D) 


(D) = default. 









KEYBOARD, PRINTING, AND DISPLAY COMMANDS 191 



Table 11-2 Programming UDKs 
Definable Keys 

F6 through F14 Help(Fl(5) 

Do(F15) Fl 7 through F20 "'. W.-x 

DECUDK Device Control String Format 

DCS Pc : PI | Kyl/Stl;...Kyn/Stn ST 

Pc is the clear parameter. ■ ■'■ ,'/.'•■',■ " ■ 

or none = Clear all keys before loading new values (default) 

1 = Clear one key at a time, before loading a new value. 

PI is the lock parameter. 

or none = Lock the keys. .'..■■ : . './.'. 

1 ~ Do not lock the keys (default). 

Ky.l/Stl;...Kyn/Stn am the key definition strings, 

The key selector number (Kyu) indicates which key you are defining. 
Key Value Key Value Key Value 



F6 


17 


Fll 


23 


Do 


29 


F7 


18 


F12 


24 


F17 


31 


F8 


19 


F13 


25 


F18 


32 


F9 


20 


F14 


26 


Fl 9 


zz 


F10 


21 


Help 


28 


■/,:'.. F20' 


34 



The string parameters (St.nl are the key definitions, encoded as pairs of 
hex codes. 

3/0 through 3/9 (0 through fl) 
4/1 through 4/(5 (A through F) 
(5/1 through (5/6 (a through f) 



192 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



Table 11-3 Printing Control Sequences 



Name 


Mnemonic 


Sequence 


Printer extent mode 


DECPEX 


Set: CSI ? 19 h 
Page. (D) 

Reset: CSI ? 19 1 
Scrolling region. 


Print form feed mode 


DECPFF 


Set: CSI ? 18 h 
Form feed. 

Reset: CSI ? 18 1 
No form feed. (D) 


Auto print mode 


MC 


On: CSI ? 5 i 
Off: CSI ? 4 i 


Printer controller mode 


MC 


On: CSI 5 i 
Off: CSI 4 i 


Print page 


MC 


CSI i or CSI i 


Print composed main 
display 


MC 


CSI ? 10 i 


Print all pages 


MC 


CSI ? 11 i 


Print cursor line 


MC 


CSI ? 1 i 


Start printer-to-host 
session 


MC 


CSI ? 9 i 


Stop printer-to-host 
session 


MC 


CSI ? 8 i 


Assign printer 
to active session 


MC 


CSI ? 18 i 


Release printer 


MC 


CSI ? 19 i 


(D) = default. 







KEYBOARD, PRINTING, AND DISPLAY COMMANDS 193 



Table 11-4 Screen Display Control Sequences 



Name Mnemonic 

Send/receive mode SRM 



Screen mode 



Scrolling mode 



Select, active 
status display* 

Select status 
line type* 



DECSCNM 



DKCSCLM 



l.)i;:CSASI) 



DKCSSDT 



(D) = default. 

* Available in VT300 mode onlv. 



Sequence 

Set: CSI 12 h 
Local echo off. (Dl 

Reset: CSI 12 1 
Local echo on. 

Set: CSI ? 5 h 
I ;ight background. 

Reset: CSI ? 5 I 
Dark background. (D) 

Set: CSI ? 4 h 
Smooth scroll. ID) 

Reset: CSI ? 4 1 
Jump scroll. 

csi Ps $ : 

p s = o. main display 
Ps = 1 . status line. 

CSI Ps $ - 

Ps = : 0. none. ' 

Ps = 1, indicator. (D) 

Ps = 2. host-writs b < 



194 KEYBOARD, PRINTING, AND DISPLAY COMMANDS 



VT300 REPORTS 



12 



Device Attributes (DA), 196 

Primary DA, 197 

Secondary DA, 199 
Terminal Identification (DECID), 200 
Device Status Reports (DSR), 201 

VT300 Operating Status, 201 

Cursor Position Report, 202 

Extended Cursor Position Report, 202 

Printer Port, 202 

User-Defined Keys, 203 

Keyboard Dialect, 203 

Locator Device Port, 204 
Terminal State Reports, 205 

Request Terminal State Report (DECRQTSR), 206 
Request Color Table Report, 206 

Terminal State Report (DECTSR), 207 

Color Table Report <DECCTR), 207 

Restore Terminal State (DECRSTS), 208 
Presentation State Reports, 209 

Request Presentation State Report (DECRQPSR), 210 

Cursor Information Report (DECCIR), 210 

Tab Stop Report (DECTABSRI, 216 

Restore Presentation State (DECRSPS), 216 
Mode Settings, 218 

Request Mode (DECRQM), 218 

Report Mode (DECRPM), 221 

Restoring Mode Settings, 223 
Set Mode (SM), 223 
Reset Mode <RM), 224 



195 



Control Function Settings, 225 

Request Selection or Setting (DECRQSS), 226 
Report Selection or Setting (DECRPSS), 227 

Saving and Restoring the Cursor State, 229 
Save Cursor (DECSC), 229 
Restore Cursor (DECRC), 229 

Window Reports, 230 

Request Displayed Extent (DECRQDE), 230 
Report Displayed Extent (DECRPDE), 230 

User-Preferred Supplemental Set (DECRQUPSS), 231 

Summary, 233 



The VT300 sends reports in response to requests from the host computer. 
These reports provide the host with the following information about the 
terminal. 

identification (type of terminal) 

cursor state 

operating status 

operating level (VT100 or VT300) 

almost all terminal states that software can set 

The host can use the reports to adjust the computing environment to match 
the terminal. 

DEVICE ATTRIBUTES (DA) 

The terminal and host computer exchange DA sequences to provide the host 
with the following information. 

conformance level (1, 2, or 3) and extensions 
basic features 
identification code 
firmware version level 
hardware options 

Based on this information, the host can 

• Use the information it receives to make the best use of the terminal's 
features. 

• Select the correct application software for the terminal. 

• Determine the cause of certain communication errors. 



196 VT300 REPORTS 



There are two types of DA exchanges between the host and the terminal, pri- 
mary DA and secondary DA. The host can request a primary DA or secondary 
DA report, depending on the information the host needs. 

Primary DA 

In this DA exchange, the host asks for the terminal's service class code and 
basic attributes. 

Host Request 

The host uses the following sequence to send this request. 



CSI c 


or 


CSI 


c 


9/11 6/3 




9/11 3/0 


6/3 



Terminal Response 

The terminal responds by sending its service code and basic attributes to the 
host. This response depends on the terminal's current operating level (VT100 
or VT300). 



CSI ? Psc 


; Psl 


J ... 


Psn c 


9/11 3/15 3/? 


3/11 3/? 


3/11 ... 


3/? 6/3 



where 

Psc indicates the terminal's service class code. The value of Psc depends 
on the terminal's current operating level, as follows. 

Psc Operating Level 

61 Level 1 (VT100 family) 

63 Level 3 (VT200 or VT300 family) 

Psl...Psn indicate which of the following extensions the terminal supports. 

Ps Meaning 

1 132 columns 

2 Printer port 

3 ReGIS graphics 

4 Sixel graphics 

6 Selective erase 

7 Soft character set (DRCS) 

8 User-defined keys 

9 National replacement character sets 



VT300 REPORTS 197 



Ps Meaning 

13 Local editing mode 

15 Technical character set 

16 Locator device port 

18 Windowing capability 

19 Dual sessions 

Primary DA Example 

Here is a typical primary DA exchange. 



Exchange 

Request 

(Host to VT300) 



Response 
(VT300 to host) 



Sequence 

CSI c or CSI c 



CSI ? 63; 1; 2; 
3; 4; 6; 7; 8; 9; 
13; 15; 16; 17; 
18; 19; c 



Meaning 

The host asks for the 
terminal's service code, 
conformance level, and 
supported extensions. 

The terminal is a service 
class 3 device (63 and 
supports the following 
extensions. 

132 columns (1) 

printer port (2) 

ReGIS graphics (3) 

Sixel graphics (4) 

selective erase (6) 

DRCS (7) 

UDKs (8) 

NRC sets (9) 

local editing mode (13) 

technical character 

set (15) 

Locator device port 

(16) 

windowing (18) 

dual sessions (19) 



Table 12-1 lists all the primary DA alias responses that the VT300 can send to 
the host. The terminal uses an alias response to identify itself to the host as 
some other type of terminal. Each response corresponds to a certain operating 
level. 



198 VT300 REPORTS 



Table 12-1 Alias Primary DA Responses From the VT300* 



Terminal Identification Sequence 

VT100 DA ESC [ ? 1:2 c 

VT101 DA ESC[?l;0c 

VT102 DA ESC|?6c 

VT125DA ESC [? 12;7;1; 10: 102 c 

VT131 DA ESC[?7c 

VT220 DA CS1 ? 62; 1; 2: 6; 7: 8: 9 c 

VT240 DA CSI ? 62: 1 ; 2; 3; 4: 6; 7; 8; 9 c 



VT 100 terminal 
VT101 terminal 
VT102 terminal 
VT1 25 terminal 
VT131 terminal 
VT220 terminal 
VT240 terminal 



* To change these alias responses, you must use the General Set-Up screen. 
See Chapter 5 of Installing and Using the VT3.30.VT340 Terminal. 

Secondary DA 

In this DA exchange, the host requests the terminal's identification code, 
firmware version level, and hardware options. 

Host Request 

The host uses the following sequence to send this request. 



CSI > c 

9/11 3/14 6/3 



or CSI > c 

9/11 3/14 3/0 6/3 



Terminal Response 

The terminal uses the following sequence to respond. 

CSI > Pp ; Pv ; Pc c 

9/11 3/14 3/? 3/11 3/? 3/11 3/? 6/3 

where 

Pp indicates the identification code for the terminal as follows. 

Pp Meaning 

18 VT330 terminal 

19 VT340 terminal 

Pv indicates the firmware version level of the terminal. Firmware is the 
software implementation of all the terminal's functions (for example, the 



VT300 REPORTS 199 



editing functions). For the VT300, all firmware is on the ROM cartridge 
installed in the rear of the terminal. 

Examples 

Pv Version 

7 X0.7 (prereleased version 0.7) 
10 VI. (released version 1.0) 

Pc indicates the ROM cartridge registration number. Pc is set to in the 
VT300. 

Secondary DA Example 

Here is a typical secondary DA exchange. 



Exchange 

Request 

(Host to VT300) 



Response 
(VT300 to host) 



Sequence 

CSI > c or 
CSI > c 



CSI > 18; 14; c 



Meaning 

The host asks for the 
terminal's identification, 
firmware version, current 
hardware options. 

The terminal identifies 
itself as a VT330 that 
uses version 1.4 firmware. 



TERMINAL IDENTIFICATION (DECID) 

This control function is similar to a primary device attributes (DA) request 
from the host. See the previous "Device Attributes" section. 

NOTE: Digital does not recommend using DECID. DECID may not be sup- 
ported in Digital terminals. You should use the primary device attributes re- 
quest for this purpose. In VT300 mode, the terminal ignores DECID. 

Host DECID Request 

ESC Z 

1/11 5/10 

Terminal Response 

The terminal uses the same response as for a primary DA request. The termi- 
nal uses this response for all operating levels (1, 2, or 3). 



200 VT300 REPORTS 



DEVICE STATUS REPORT (DSR) 

The host computer and terminal exchange DSR sequences to provide the host 
with the operating status of the following seven features. 

VT300 operating status 
Cursor position 
Cursor position with page 
Printer port 
User-defined keys 
Keyboard dialect 
Locator device port 

DSR requests and reports follow one of two formats, ANSI standard or DEC 
private. The format for each is as follows. 



ANSI standard 


CSI Ps n 

9/11 3/? 6/14 


DEC private 


CSI ? Ps n 

9/11 3/15 3/? 6/14 




where 




Ps indicates the type of DSR requested. 



There is a different DSR request for each feature. The following sections de- 
scribe the possible DSR reports. If the terminal is in printer controller mode 
(Chapter 11), the printer receives the DSR request. 

DSR — VT300 Operating Status 

The host requests the terminal's operating status. 

Exchange Sequence Meaning 



Request 
(HosttoVT300) 

Responses 
(VT300 to host) 



CSI 5 n 

CSI n 

or 
CSI3n 



The host requests the terminal's 
operating status. The host asks if the 
terminal is in good operating condition. 

The terminal indicates that it is 
in good operating condition. 



The terminal indicates that it has a 
malfunction. 



VT300 REPORTS 201 



DSR — Cursor Position Report (CPR) 

The host asks the terminal for a cursor position report. 



Exchange 


Sequence 


Meaning 


Request 


CSI6n 


The host asks for a cursor 


(HosttoVT300) 




position report (CPR). 


CPR response 


CSI PI; Pc R 


The terminal indicates that 


(VT300 to host) 




the cursor is currently at 
line PI, column Pc. 



DSR — Extended Cursor Position Report (DECXCPR) 

The host asks the terminal for the current cursor position, including the cur- 
rent page number. 



Exchange 

Request 

(Host to VT300) 



Sequence 
CSI ? 6 n 



DECXCPR response CSI PI; Pc; Pp R 

(VT300 to host) 



Meaning 

The host asks for an extended 
cursor position report 
(DECXCPR). 

The terminal indicates that 
the cursor is currently at 
line PI, column Pc, on page 
Pp. 



DSR — Printer Port 

The host asks for the status of the terminal's printer. 

NOTE: Host software should check the printer status before entering any print 
mode or starting any printing function. 



Exchange 

Request 
(HosttoVT300) 

Possible responses 
(VT300 to host) 



Sequence 
CSI ? 15 n 

CSI ? 13 n 



CSI ? 10 n 



Meaning 

The host asks for the current 
printer status. 

No printer. The data terminal 
ready (DTR) signal has not 
been asserted on the printer 
port since the last power-up 
or reset. 

Printer ready. DTR is 
asserted on the printer port. 



202 VT300 REPORTS 



CSI ? 11 n Printer not ready. DTR is not 

currently asserted on the 
printer port. 

CSI ? 18 n Printer busy. DTR is asserted 

on the printer port, but the 
other session is using the 
printer (Chapter 14). 

InVTIOOmode.the 
terminal sends the "Printer 
not ready" sequence above. 

CSI ? 19 n Printer assigned to other 

session. DTR is asserted 
on the printer port, but 
the printer is assigned 
to the other session. The 
printer is not available to 
this session (Chapter 14). 

InVTIOOmode, the 
terminal sends the "No 
printer" sequence above. 

DSR — User-Defined Keys (VT300 Mode Only) 

The host asks if the user-defined keys (UDKs) are locked or unlocked. 



Exchange 

Request 

(Host to VT300) 

Possible responses 
(VT300 to host) 



Sequence 
CSI ? 25 n 

CSI ? 20 n 
CSI ? 21 n 



Meaning 

The host asks if UDKs are 
locked or unlocked. 

UDKs are unlocked. 
UDKs are locked. 



DSR — Keyboard Dialect 

The host asks for the current keyboard dialect and the keyboard's operating 
status. 



Exchange 

Request 

(Host to VT300) 



Sequence 
CSI ? 26 n 



Meaning 

The host asks for the 
keyboard dialect and status. 



VT300 REPORTS 203 



Response 
(VT300 to host) 



CSI ? 27; Pla; 

Pstn 

where 



Pla 



Dialect 



The keyboard dialect is Pla, 
and the keyboard status is 
Pst. 



Pst = Keyboard Status* 

= Keyboard ready. 

The terminal sends 
typed characters to 
the current session 
(Chapter 14). 

3 = No keyboard. The 
terminal does not 
detect the keyboard. 

8 = Keyboard busy. The 
other session is 
currently using the 
keyboard (Chapter 
14). 



* The terminal only sends Pst in VT300 mode. 

DSR — Locator Device Port (VT300 Mode Only) 

The host can ask for the status or identification of the locator device. You can 
connect devices such as a mouse or graphics tablet to the locator port of a 
VT300. 



1 


= 


North American 


2 


= 


British 


3 


= 


Flemish 


4 


= 


Canadian (French) 


5 


= 


Danish 


6 


= 


Finnish 


7 


= 


German 


8 


= 


Dutch 


9 


= 


Italian 


10 


= 


Swiss (French) 


11 


= 


Swiss (German) 


12 


= 


Swedish 


13 


= 


Norwegian 


14 


= 


French/Belgian 


15 


== 


Spanish 


16 




Portuguese 



Exchange 

Status request 
(Host to VT300) 

Possible responses 
(VT300 to host) 



Sequence 
CSI ? 55 n 

CSI ? 53 n 
CSI ? 50 n 



Meaning 

The host asks for the status 
of the locator device port. 

No locator device. The 
terminal cannot detect 
a locator device. 

Locator device ready. The 
terminal detects a locator 
device. 



204 VT300 REPORTS 



Identification 

request 

(Host to VT300) 

Possible responses 
(VT300 to host) 



CSI ? 58 n Locator device busy. The 

other session is currently 
using the locator device 
(Chapter 14). 

CSI ? 56 n The host asks what kind of 

locator device is connected 
to the locator device port. 

CSI ? 57 ; n Cannot identify the locator 

device. There is no locator 
device connected, or the 
device connected is not 
Digital's optional mouse or 
tablet. 

Applications that receive 
this response should request 
the locator status before 
reporting a problem to the 
user. 

CSI ? 57 ; 1 n The terminal identifies the 

device as Digital's optional 
mouse. 

CSI ? 57 ; 2 n The terminal identifies the 

device as Digital's optional 
tablet. 



TERMINAL STATE REPORTS (VT300 MODE ONLY) 

The host can request the terminal's current operating state. In response to this 
request, the terminal returns a terminal state report. The host can use the in- 
formation in the report to save the current terminal state. Later, the host can 
restore the terminal to the saved state. 

This operation is useful for applications that need to temporarily change the 
terminal's operating state. When the application is finished, it can restore the 
terminal to the previous operating state. 

A terminal state report is a device control string. The report indicates the set- 
tings of most of the terminal's features. The terminal sends the report in re- 
sponse to a request terminal state report (DECRQTSR) sequence from the 
host. 



VT300 REPORTS 205 



There are two terminal state reports. 

Terminal state report (DECTSR) 
Color table report (DECCTR) 

Request Terminal State Report (DECRQTSR) — Host To VT300 

The host sends this control function to request a terminal state report 
(DECTSR) or color table report (DECCTR). The terminal responds by sending 
a report indicating the settings of many device attributes. 

CSI Ps $ u 

9/11 3/? 2/4 7/5 

where 

Ps indicates the type of report the host requests from the terminal. 

Ps Report Requested 

or none Ignored. No report sent. 

1 Terminal state report (DECTSR) 

2 Color table report (DECCTR) 

Request Color Table Report - When you use DECRQTSR to request a color 
table report, you can include an additional parameter, Ps2. Ps2 selects which 
color coordinate system the terminal uses to report the color map, HLS (hue/ 
lightness/saturation) or RGB (red/green/blue). Use the following format to re- 
quest a color table report. 



CSI 


2 


; Ps2 


$ 


u 


9/11 


3/2 


3/11 3/? 


2/4 


7/5 



where 

Ps2 indicates the color coordinate system the terminal uses 
the send the report. 

Ps2 Color Coordinate System 

or none HLS (default) 

1 HLS 

2 RGB 

206 VT300 REPORTS 



Terminal State Report (DECTSR) — VT300 to Host 

The terminal sends this sequence in response to a request terminal state report 
(DECRQTSR) sequence. DECTSR informs the host of the entire state of the 
terminal, except for user defined key definitions and the current soft character 
set. 

PROGRAMMING TIP: Applications can use the information in the terminal 
state report to save the current terminal state. Later, the application can re- 
store the terminal to the saved state. 

This operation is useful for applications that need to temporarily change the 
terminal's operating state. When the application is finished, it can restore the 
terminal to the previous operating state. You use the restore terminal state 
(DECRSTS) function to restore the terminal state. DECRSTS is described later 
in this chapter. 

The DECTSR format is as follows. 

DCS 1 $ s D1...D196 <checksuml> <checksum2> ST 

9/0 3/1 2/4 7/3 9/12 

where 

D1...D196 is a data string indicating the status of most of the terminal's 
features. There are 196 bytes in the data string (D1...D196). D1...D196 are 
in the range 4/0 to 4/15 in the code table (Chapter 2). Bit 6 of each Dn is 
always on, bits 4, 5, and 7 of Dn are always off. 

Notes on DECTSR 

• Software should not expect the format of DECTSR to be the same for 
all members of the VT300 family, or for different revisions within each 
member of the family. 

Color Table Report (DECCTR) — VT300 to Host 

The terminal sends this sequence in response to a request terminal state report 
(DECRQTSR) sequence from the host. DECCTR informs the host of the termi- 
nal's current color settings. 

PROGRAMMING TIP: Applications can use the information in the color table 
report to save the current color map. Later, the application can restore the 
saved color map. 

VT300 REPORTS 207 



This operation is useful for applications that need to temporarily change the 
terminal's color map. When the application is finished, it can restore the color 
map that was in effect before the application changed it. You use the restore 
terminal state (DECRSTS) function to restore the color map. DECRSTS is de- 
scribed in the next section. 



DCS 2 


$ 


s 


D...D 


ST 


9/0 3/2 


2/4 


7/3 




9/12 



where 

D...D is the data string containing the color table information. The data 
string is divided into groups of five 
values, as follows. 

Pc; Pu; Px; Py; Pz / Pc; Pu; Px; Py; Pz / ... 

where 

Pc is the color number (0 through 255). 

; (semicolon, 3/11) separates the parameters. 

Pu indicates the universal coordinate system used. 

Pu Coordinate System 

1 HLS (hue, lightness, saturation) 

2 RGB (red, green, blue) 

Px; Py; Pz are color coordinates in the specified coordinate system. 

Parameter HLS Values RGB Values 

Px to 360 (hue angle) to 100 (red intensity) 

Py to 100 (lightness) to 100 (green intensity) 

Pz to 100 (saturation) to 100 (blue intensity) 

Restore Terminal State (DECRSTS) — VT300 Mode Only 

This sequence restores the terminal to a previous state specified in a terminal 
state report (DECTSR). There are two terminal state reports. 

Terminal state report (DECTSR) 
Color table report (DECCTR) 

208 VT300 REPORTS 



PROGRAMMING TIP: Applications can use DECRSTS to restore the terminal 
to a previous operating state specified in a terminal state report. See the 
"Terminal State Report (DECTSR)" and "Color Table Report (DECCTR)" sec- 
tions in this chapter. 



ilable in: VT300 mode 






DCS Ps $ p 


D...D 


ST 


9/0 3/? 2/4 7/0 




9/12 



where 

Ps indicates the format of the data string (D...D). You can use one of the 
two following formats for the the data string. These formats correspond to 
the formats used by the two terminal state reports (DECTSR). Make sure 
you use the format used by the report you are restoring. 

Ps Data String Format 

Error, restore ignored. 

1 Selects the format of the terminal state report (DECTSR). 

2 Selects the format of the color table report (DECCTR). 

D...D is a data string that contains the restored information. This string is 
identical to the data string used by the report you are restoring. 

Notes on DECRSTS 

• If there is an invalid value in the DECRSTS sequence, the terminal 
ignores the rest of the sequence. This action may leave the terminal 
in a partially restored state. 

• Software should not expect the format of the terminal state report 
(DECTSR) to be the same for all VT300 family members. 

PRESENTATION STATE REPORTS (VT300 MODE ONLY) 

The terminal can send two presentation state reports. 

Cursor information Reports on the cursor position, including 

report (DECCIR) its visual attributes and character 

protection attributes. Also reports on 
origin mode (DECOM), and the current 
active character sets. 

Tab stop report Reports the current tab stop settings. 

(DECTABSR) 

VT300 REPORTS 209 



The host can request the terminal's current presentation state. In response to 
this request, the terminal returns a presentation state report. The host can use 
the information in the report to save the current presentation state. Later, the 
host can restore the terminal to the saved state. 

This operation is useful for applications that need to temporarily change the 
terminal's presentation state. When the application is finished, it can restore 
the terminal to the previous presentation state. 

A presentation state report is a device control string. The terminal sends the 
report in response to a request presentation state report (DECRQPSR) se- 
quence from the host. 

Request Presentation State Report (DECRQPSR) 
— Host To VT300 

The host sends this sequence to request a cursor information report (DECCIR) 
or a tabulation stop report (DECTABSR>. 

CSI Ps $ w 
9/11 3/? 2/4 7/7 

where 

Ps indicates which report the host requests. 

Ps Report Requested 

Error, request ignored 

1 Cursor information report (DECCIR) 

2 Tab stop report (DECTABSR) 

Cursor Information Report (DECCIR) — VT300 to Host 

The terminal sends this sequence in response to a request presentation state 
report (DECRQPSR) sequence. DECCIR reports the status of the cursor posi- 
tion, including visual attributes and character protection attributes. DECCIR 
also reports the status of of origin mode (DECOM) and the current active char- 
acter sets. 

PROGRAMMING TIP: Applications can use the information in the cursor in- 
formation report to save the current presentation state. Later, the application 
can restore the terminal to the saved state. 



210 VT300 REPORTS 



This operation is useful for applications that need to temporarily change the 
terminal's presentation state. When the application is finished, it can restore 
the terminal to the previous presentation state. You use the restore presenta- 
tion state (DECRSPS) function to restore the presentation state. DECRSPS is 
described later in this chapter. 



DCS 1 


$ 


u 


D...D 


ST 


9/0 3/1 


2/4 


7/5 




9/12 



where 

D...D is the data string containing the cursor information. The format for 
this data string is as follows. 

Pr; Pc; Pp; Srend; Satt; Sflag; Pgl; Pgr; Scss; Sdesig 

where 



Pr is the number of the line the cursor is on. 

Pc is number of the column the cursor is at. 

Pp is the number of the current page. 

Srend is one or more characters indicating the visual attributes 
(such as bold and blinking) currently set for writing (Chapter 7). 

To find out what attributes are set, you must convert the character 
to an 8-bit binary number. You can use the code table in Chapter 2 
to convert characters. After you convert a character, you can find 
the meaning of its 8-digit binary number in the following table. The 
table lists the most significant bit (8) to least significant bit (1). 



Bit 

8 

7 



Attribute 



Bit Value 
Always (off). 
Always 1 (on). 



6 



Extension 
indicator 



Invisible 



1 = another character (byte) of 
attribute data follows this 







one. 

no more attribute data. 



= off. 

1 = on. 



VT300 REPORTS 211 



4 


Negative 


= off. 




image 


1 = on. 


3 


Blinking 


= off. 

1 = on. 


2 


Underline 


= off. 

1 = on. 


1 


Bold 


= off. 

1 = on. 



Example 

If the bold and underline attributes are on for the current writ- 
ing rendition, Srend is the ASCII uppercase C character (bi- 
nary 01000011). 

Satt is one or more characters indicating whether the selective erase 
attribute (DECSCA, Chapter 8) is currently on for writing. 

To find if the attribute is set, you must convert each character to an 
8-bit binary number. Use the same method you used to convert the 
Srend parameter above. Then use the following table to find the 
meaning of the 8-bit binary number. 



Bit 


Attribute 


Bit Value 


8 


— 


Always (off). 


7 


— 


Always 1 (on). 


6 


Extension 
indicator 


1 = another character (byte) of 
selective erase data 
follows this one. 

= no more protection data. 


5 


— 


— Reserved for future use. 


4 


— 


— Reserved for future use. 


3 


— 


— Reserved for future use. 


2 


— 


— Reserved for future use. 


1 


Selective 
erase 


= off. 

1 = on. 



212 VT300 REPORTS 



Example 

If the selective erase attribute is currently on for writing, then 

Satt is the ASCII uppercase A character (binary 01000001). 

Sflag is one or more characters that indicate several flags and 
modes the terminal must save. 

To see the current state of the flags and modes, you must convert 
each character to an 8-bit binary number. Use the same method you 
used to convert the Srend and Satt parameters above. Then use the 
following table to find the meaning of the 8-bit binary number. 



Bit 

8 

7 



Attribute 



Bit Value 

Always (off). 
Always 1 (on). 



6 

5 

4 



Extension 
indicator 



Auto 
wrap 

Single 
shift 3 (SS3) 
setting 

Single 

shift 2 (SS2) 
setting 

Origin 
mode 



1 = another character (byte) of 
flag data follows this one. 
= no more flag data. 

— Reserved for future use. 

1 = auto wrap pending 

= auto wrap not pending 

1 = G3 is mapped into GL for 

the next typed character 
only. 

= single shift 3 is off. 

1 = G2 is mapped into GL for 

the next typed character 
only. 

= single shift 2 is off. 

1 = origin mode set 

= origin mode reset 



Example 

If origin mode is set, auto wrap is pending, and a single shift 
3 has been received, then Sflag is the ASCII upper case M 
character (binary 01001101). 



VT300 REPORTS 213 



Pgl indicates the number of the logical character set (GO through 
G3) mapped into GL. 



= GO is in GL. 

1 = Gl is in GL. 



2 = G2 is in GL. 

3 = G3 is in GL. 



Pgr indicates the number of the logical character set (GO through 
G3) mapped into GR. 



= GO is in GR. 

1 = Gl is in GR. 



2 = G2 is in GR. 

3 = G3 is in GR. 



Scss is a character indicating the size of the character sets in GO 
through G3. 

To find out what the character means, you must convert it to an 
8-bit binary number. Use the same method you used to convert the 
Srend, Satt, and Sflag parameters. Then use the following table to 
find the meaning of the 8-bit binary number. 



Bit 


Indicates 


Bit Value 


8 


— 


Always (off) 


7 


— 


Always 1 (on) 


6 


Extension 
indicator 


1 = another character (byte) of 
character size data follows 
this one. 

= no more size data. 


5 


— 


= reserved for future use. 


4 


G3 set 
size 


= 94 characters. 

1 = 96 characters. 


3 


G2set 
size 


= 94 characters. 

1 = 96 characters. 


2 


Glset 
size 


= 94 characters. 

1 = 96 characters. 


1 


GO set 
size 


= 94 characters. 

1 = 96 characters. 



214 VT300 REPORTS 



Example 

Suppose the following conditions exist. 

• ISO Latin-1 supplemental is designated as G2 and G3. 

• ASCII is designated as GO and Gl. 

Then Scss is the backslash ASCII \ character (binary 
01001100). 

Sdesig is a string of intermediate and final characters indicating the 
character sets designated as GO through G3. These final characters 
are the same as those used in select character set (SCS) sequences 
(Chapter 5). 

Example 

Suppose the ASCII character set is designated as GO, DEC Special 
Graphic as Gl, and DEC Supplemental Graphic as G2 and G3. The 
Sdesig string would be B0%5%5. Each character corresponds to a 
final character in an SCS sequence, as follows. 



GO 


Gl 


G2 


G3 


B 





%5 


%5 


ASCII 


DEC 

Special 

Graphic 


DEC 

Supplemental 

Graphic 


DEC 

Supplemental 

Graphic 



Example 

The following is an example of a cursor information report. 

DCS 1 $ u 1; 1; 1; @; @; @; 0; 2; @; BB%5%5 ST 
where 

1; 1; 1; indicates that the cursor is at row 1, column 1, on the first page. 

@; @; @; indicates that no visual character attributes or protection attri- 
butes are on at the cursor position, DECOM is reset, no SS2 pending, no 
SS3 pending, and no autowrap pending. 

0; 2; indicates that GO is mapped into GL, and G2 is in GR. 

@; all character sets have 94 characters. 

BB%5%5 indicates that ASCII is in GO and Gl, and that DEC 
Supplemental Graphic is in G2 and G3 

VT300 REPORTS 215 



Notes on DECCIR 

• The cursor information in a DECCIR sequence is the same informa- 
tion saved through a save cursor (DECSC) command. 

• DECCIR does not save active SPA and SSA control functions. 

Tab Stop Report (DECTABSR) — VT300 To Host 

The terminal sends this sequence to the host in response to a request presenta- 
tion state report (DECRQPSR) sequence. DECTABSR informs the host of the 
terminal's current tab settings. 

PROGRAMMING TIP: Applications can use the information in the tab stop 
report to save the current tab stops. Later, the application can restore the 
saved tab stops. 

This operation is useful for applications that need to temporarily change the 
terminal's tab stops. When the application is finished, it can restore the tab 
stops that were in effect before the application changed them. You use the re- 
store presentation state (DECRSPS) function to restore tab stops. DECRSPS is 
described later in this chapter. 



DCS 2 


$ 


u 


D...D 


ST 


9/0 3/2 


2/4 


7/5 


. . . 


9/12 



where 

D...D is a data string indicating the column number location of each tab 
stop. 

Example 

The following is an example of a DECTABSR sequence. 

DCS 2 $ u 9/ 17/ 25/ 33/ 41/ 49/ 57/ 65/ 73 ST 
where 

9, 17, 25, 33, 41, 49, 57, 65, and 73 are the column numbers for tab stops. 

Restore Presentation State (DECRSPS) — VT300 Mode Only 

This control function restores the terminal to a previous state based on one of 
the presentation state reports. There are two presentation state reports. 

Cursor information report (DECCIR) 
Tab stop report (DECTABSR) 

216 VT300 REPORTS 



A DECRSPS sequence can only restore the information from one report at a 
time, cursor information or tab stop. 

PROGRAMMING TIP: Applications can use DECRSPS to restore the terminal 
to a previous state specified in a presentation state report. See the previous 
"Cursor Information Report (DECCIR)" and "Tab Stop Report (DECTABSR)" 
sections in this chapter. 

Available in: VT300 mode 



DCS Ps 


$ 


t 


D...D 


ST 


9/0 3/? 


2/4 


7/4 


it. 


9/12 



where 

Ps indicates the format of the data string (D...D). You can use one of the 
two following formats for the data string. These formats correspond to the 
formats used in the two presentation state reports (DECPSR). Make sure 
you use the format of the report you are restoring. 

Ps Data String Format 

Error, restore ignored. 

1 Selects the format of the cursor information report (DECCIR). 

2 Selects the format of the tab stop report (DECTABSR). 

D...D is a data string that contains the restored information. This string is 
identical to the data string used in the report you are restoring — the cur- 
sor information report (DECCIR) or tab stop report (DECTABSR). 

Example 

The following DECRSPS sequence restores tab stops according to the tab stop 
report (DECTABSR). 

DCS 2 $ u 9; 17; 25; 33; 41; 49; 57; 65; 73 ST 

Note that the data string format above is exactly the same as the format for 
the tab stop report (DECTABSR). 

Notes on DECRSPS 

• If there is an invalid value in the DECRSPS sequence, the terminal 

ignores the rest of the sequence. This action may leave the terminal 
in a partially restored state. 

VT300 REPORTS 217 



MODE SETTINGS (VT300 MODE ONLY) 

The host can request the current settings of any ANSI or DEC private modes. 
In response to this request, the terminal returns a report indicating which 
modes are set and which are reset. The host can use the information in the 
report to save the current mode settings. Later, the host can restore the mode 
settings to their saved state. 

This operation is useful for applications that need to temporarily change a num- 
ber of modes. When the application is finished, it can restore the modes to 
their previous state. 

The host requests the setting of a mode with a DECRQM sequence. The termi- 
nal responds with a DECRPM sequence. The host can then restore a saved 
setting with an SM or RM sequence. The following sections describe these 
sequences. 

Request Mode (DECRQM) — Host To VT300 

The host sends this control function to find out if a particular mode is set or 
reset. The terminal responds with a report mode function (DECRPM). 

There are two versions of the DECRQM function, for ANSI and DEC private 
modes. 

Requesting ANSI Modes 

CSI Pa $ p 

9/11 3/? 2/4 7/0 



where 



Pa indicates the ANSI mode that the host is asking about. Table 12-2 lists 
the values for Pa. 



Requesting DEC Private Modes 



CSI ? Pd $ p 

9/11 3/15 3/? 2/4 7/0 



where 



Pd indicates the DEC private mode the host is asking about. Table 12-3 
lists the values for Pd. 

218 VT300 REPORTS 



Examples 

• The following sequences request the setting of some ANSI modes. 

Host Request Meaning 

CSI 2 $ p What is the current state of keyboard 

action mode (KAMI? (KAM = 2) 

CSI 4 $ p What is the current state of 

insert/replace mode (IRM)? (IRM = 4) 



• 



The following sequences request the setting of some DEC private 
modes. 

Host Request Meaning 

CSI ? 60 $ p What is the current state of horizontal 

cursor coupling mode (DECHCCM)? 
(HCCM = 60) 

CSI ? 6 $ p What is the current state of origin mode 

(DECOM)? (DECOM = 6) 

Notes on DECRQM 

• A DECRQM sequence can only ask about one mode at a time. 



VT300 REPORTS 219 



Table 12-2 ANSI Modes for DECRQM. DECRPM, SM, and RM 



Mode 

Guarded area transfer 
Keyboard action 
Control representation 
Insert/replace 
■Erasure 

Horizontal editing 
Send/receive 
Multiple area transfer 
Transmit termination 
Selected area transfer 
Line feed/new line 



Mnemonic 


Pa 


GATM 


1 


KAM 


' 2 


CRM* 


3 


IRM 


4 


ERM 


6 


HEM} 


10 


SRM 


12 


MATM 


15 


TTM 


16 


SATM 


■: 1.7 


LNM 


20 



* The host cannot change the setting of CRM You can only change CRM 
from set-up. If CRM is set. the terminal ignores DECRQM and most other 
control functions. ■ 

} This control function is permanently reset. 



Table 12-3 DEC Private Modes for DECRQM. DECRPM, SM, and RM 



Mode 

Cursor keys 
ANSI 
Column 
Scrolling 

Screen 

Origin 

Autowrap 

Autorepeat 

Edit 

1 ine transmit 

Space compression 
field delimiter 
Transmit execution 
Edit key execution 
Print form feed 
Printer extent 



Mnemonic 

DECCKM 

DECANM 

DECCOLM 

DECSCLM 

DECSCNM 

DECOM 

DECAWM 

DECARM 

DECEDM 

DECLTM 



DECTEM 
DECEKEM 
DECPFF 
DECPEX 



Pd 

2 
3 
4 
ft 

6 

7 
8 

10 

II 



DECSCFDM 13 



14 
16 
18 
19 



220 VT300 REPORTS 



Table 12-3 DEC Private Modes for DECRQM, DECRPM, SM, and RM 

(Cont) 



Mode 

Text cursor enable 
4010/4014 emulation 
National replacement 
character set 
Graphics expanded print 
Graphics print color 

Graphics print color syntax 
Graphics print background 
Graphics rotated print 
VT131 transmit 
Horizontal cursor coupling- 
Vertical cursor coupling 
Page cursor coupling 
Numeric keypad 
Backarrow key 

Keyboard usage 
Transmit rate limiting 



Report Mode (DECRPM) — VT300 To Host 

The terminal sends this control function in response to a request mode 
(DECRQM) function. DECRPM informs the host whether a certain mode is set 
or reset. 

PROGRAMMING TIP: Applications can use the information in the DECRPM 
report to save the current mode settings. Later, the application can restore the 
saved mode settings. 

This operation is useful for applications that need to temporarily change some 
of the terminal's mode settings. When the application is finished, it can restore 
the mode settings that were in effect before the application changed them. You 
use the set mode (SM) and reset mode (RM) functions to restore mode settings. 
SM and RM are described later in this chapter. 

There are two versions of DECRPM, for ANSI and DEC private modes. 



Mnemonic 


Pd 


DECTCEM 


25 


DECTEK 


35 


DECNRCM 


42 


DECGEPM 


43 


DECGPCM 


44 


DECGPOS 


45 


DECGPBM 


46 


DECGRPM 


47 


DEC131TM 


53 


DECHCCM 


60 


DECVCCM 


61 


DECPCCM 


64 


DECNKM 


(56 


DECBKM 


67 


DECKBUM 


68 


DECXRLM 


73 



VT300 REPORTS 221 



Reporting ANSI Modes 



CSI Pa ; Ps $ y 

9/11 3/? 3/11 3/? 2/4 7/9 



where 



Pa indicates the ANSI mode the terminal is reporting. Table 12-2 lists the 
values for Pa. 

Ps indicates the setting of the mode, as follows. 

Ps Setting of Mode 

Mode not recognized. 

1 Set. 

2 Reset. 

3 Permanently set. 

4 Permanently reset. 

Reporting DEC Private Modes 

CSI ? Pd ; Ps $ y 

9/11 3/15 3/? 3/11 3/? 2/4 7/9 

where 



Pd indicates the DEC private mode the terminal is reporting. Table 12-3 
lists the values for Pd. 

Ps indicates the setting of the mode. The Ps values are the same as for 
the ANSI version above. 

Examples 

• The following sequences report the setting of some ANSI modes. 

VT300 Report Meaning 

CSI 2 ; 1 $ y Keyboard action mode (KAM) is 

currently set. (KAM = 2, set = 1) 



222 VT300 REPORTS 



CSI 4 ; 2 $ y Insert/replace mode is currently 

reset (IRM). (IRM = 4, reset = 2) 

• The following sequences report the setting of some DEC private 
modes. 

VT300 Report Meaning 

CSI ? 60; 1 $ y Horizontal cursor coupling mode is 

currently set. (DECHCCM = 60, 

set = 1) 

CSI ? 6 ; 2 $ y Origin mode (DECOM) is currently 

reset. (DECOM = 6, reset = 2) 

Notes on DECRPM 

• The terminal can only report on one mode at a time. 

Restoring Mode Settings (SM and RM) 

ANSI and DEC private modes are control functions that have only two set- 
tings, set or reset. Soft terminal reset and hard terminal reset affect many 
control functions, including some ANSI and DEC private modes. 

PROGRAMMING TIP: Applications can use the SM and RM functions to re- 
store any number of VT300 modes to a desired state. See the previous "Report 
Mode (DECRPM)" section in this chapter for details. 

Set Mode (SM) - This control function has two versions. You use the ANSI 
version to set one or more ANSI modes. You use the DEC private version to 
set one or more DEC private modes. You cannot set ANSI and DEC private 
modes with the same SM sequence. 

Setting ANSI Modes 



CSI Pa 


t ... 


; Pa 


h 


9/11 3/? 


3/11 ... 


3/11 3/? 


6/8 



where 

Pa indicates the ANSI mode to set. Table 12-2 lists Pa values for ANSI 
modes. You can use more than one Pa value in a sequence. 



VT300 REPORTS 223 



Setting DEC Private Modes 

CSI ? Pd ; ... ; Pd h 

9/11 3/15 3/? 3/11 ... 3/11 3/? 6/8 

where 

Pd indicates a DEC private mode to set. Table 12-3 lists the Pd values for 
DEC private modes. You can use more than one Pd value in a sequence. 

Examples 

• ANSI Modes 

The following sequence sets insert/replace mode (IRM) and erasure 
mode (ERM). 

CSI 4 ; 6 h 

where 

4 indicates insert/replace mode. 
6 indicates erasure mode. 

• DEC Private Modes 

The following sequence sets scrolling mode (DECSCLM) and hori- 
zontal cursor coupling mode (DECHCCM). 

CSI ? 4; 60 h 

where 

4 indicates scrolling mode. 

60 indicates horizontal cursor coupling mode. 

Reset Mode (RM) - There are two versions of this control function. You use 
the ANSI version to reset one or more ANSI modes. You use the DEC private 
version to reset one or more DEC private modes. You cannot reset ANSI and 
DEC private modes with the same RM sequence. 

Resetting ANSI Modes 



CSI Pa 


* *•• 


; Pa 


1 


9/11 3/? 


3/11 ... 


3/11 3/? 


6/12 



where 

Pa indicates an ANSI mode to reset. Table 12-2 lists the Pa values for 
ANSI modes. You can use more than one Pa value in a sequence. 

224 VT300 REPORTS 



Resetting DEC Private Modes 



where 



CSI ? Pd 


t ... 


; Pd 


1 


9/11 3/15 3/? 


3/11 ... 


3/11 3/? 


6/12 



Pd indicates a DEC private mode to reset. Table 12-3 lists the Pd values 
for DEC private modes. You can use more than one Pd value in a 
sequence. 



Examples 

• ANSI Modes 

The following sequence resets insert/replace mode (IRM) and erasure 
mode (ERM). 

CSI 4 ; 6 1 

where 

4 indicates insert/replace mode. 
6 indicates erasure mode. 

• DEC Private Modes 

The following sequence resets scrolling mode (DECSCLM) and hori- 
zontal cursor coupling mode (DECHCCM). 

CSI ? 4; 60 1 

where 

4 indicates scrolling mode. 

60 indicates horizontal cursor coupling mode. 

CONTROL FUNCTION SETTINGS (VT300 MODE ONLY) 

The host can request the current selection or setting of any control function 
listed in Table 12-4. In response to this request, the terminal returns a report 
indicating the current section or setting of the selected control function. The 
host can use the information in the report to save the current setting. Later, 
the host can restore the control function to its saved state. 

This operation is useful for applications that need to temporarily change a num- 
ber of control function settings. When the application is finished, it can restore 
the control functions to their previous state. 



VT300 REPORTS 225 



The host requests the setting of a control function with a DECRQSS sequence. 
The terminal responds with a DECRPSS sequence. The host can then restore 
the control function, based on the DECRPSS report. The following sections de- 
scribe DECRQSS and DECRPSS. 

Table 12 4 Control Functions for DECRQSS Requests 







Intermediate and 


Control Function 


Mnemonic 


Final Character(s) 


Protected fields attributes 


DECPRO 




Select active status display 


DECSASD 


$} 


Set character attribute 


DECSCA 


"q 


Set conformance level 


DECSCL 


"P 


Bet col'mmss per page 


DECSCPP 


$! 


Set lines per page 


DECSLPP 


t 


Set status line type 


DECSSDT 


$~ 


Set top and bottom margins 


DECSTBM 


r 


Set transmit termination 


DECTTC 


S ; fl ■■''■ : ' : ^ 


eiiawier" 7 . 






Transmit line termination 


DECTLTC 


\s 



character 

Select graphic rendition 



SCM 



m 



Request Selection or Setting (DECRQSS) — Host To VT300 

The host sends this sequence to ask for the setting of a control function. The 
terminal responds with a report selection or setting (DECRPSS) sequence. 



DCS $ 

9/0 2/4 



q 

7/1 



D...D ST 

9/12 



where 



D...D indicates the control function the host is asking about. D...D consists 
of the intermediate and/or final characters of the control function re- 
quested. Table 12-4 lists the control functions the host can ask about, with 
their final characters. 



226 VT300 REPORTS 



Examples 



• The following DECRQSS sequence asks about the select graphic 
rendition (SGR) function. 

DCS $ q m ST 
where 

m is the final character of the SGR sequence. 

• The following sequence asks about the set columns per page 
(DECSCPP) function. 

DCS $ q $ | ST 

where 

$ | are the intermediate and final characters of the DECSCPP 
sequence. 

Notes on DECRQSS 

• A DECRQSS sequence can only ask about one control function at a 
time. 

Report Selection or Setting (DECRPSS) — VT300 To Host 

The terminal sends the host this sequence in response to a request selection or 
setting (DECRQSS) sequence. The terminal sends DECRPSS to report the set- 
ting of a particular control function. 

PROGRAMMING TIP: Applications can use the information in the DECRPSS 
report to save the current selections or settings of some control functions. 
Later, the application can restore the control functions to their saved state. 

This operation is useful for applications that need to temporarily change the 
settings of some of the terminal's control functions. When the application is 
finished, it can restore the control functions to their previous state. 



DCS Ps 


$ 


r 


D...D 


ST 


9/0 3/? 


2/4 


7/1 




9/12 



VT300 REPORTS 227 



where 

Ps indicates whether or not the request from the host is valid. 

= host's request is valid. 

1 = host's request is invalid. 

D...D indicates the current setting of a valid control function that the host 
asked about. D...D consists of all the characters in the control function, 
except the CSI (9/11) or ESC [ (1/11, 5/11) introducer characters. 



Examples 



The host requests the setting of the select graphic rendition (SGR) 
function. If the current graphic rendition is blinking, reverse, and 
invisible, the terminal responds with the following DECRPSS 
sequence. 

DCS S r ; 5 ; 7 ; 8 m ST 

where 

; 5 ; 7 ; 8 m are all the characters in the SGR sequence, 
except CSI. 

The host requests the setting of the set top and bottom margin 
function (DECSTBM). If the current top and bottom margins are set 
to include the complete screen area, the terminal responds with the 
following DECRPSS sequence. 

DCS $ r 1 ; 24 r ST 

where 

1 ; 24 r are all the characters in the DECSTBM sequence, ex- 
cept CSI. 

The host requests the setting of a function that the terminal does 
not recognize. The terminal responds with the following DECRPSS 
sequence. 



228 VT300 REPORTS 



DCSl$rST 

The terminal does not send a data string (D...D) to the host when 
the terminal receives an invalid request. 

SAVING AND RESTORING THE CURSOR STATE 

The save cursor function (DECSC) stores many of the terminal's selections and 
settings. The restore cursor function (DECRC) restores the terminal to the 
state saved by DECSC. 

PROGRAMMING TIP: Applications can use DECSC to save the current set- 
tings of many modes and control functions. Later, the application can use 
DECRC restore the control functions and modes to their saved state. 

This operation is useful for applications that need to temporarily change the 
settings of some of the terminal's modes and control functions. When the appli- 
cation is finished, it can restore the modes and control functions to their pre- 
vious state. 

Name Sequence Action 

Save cursor ESC 7 Saves the following in the terminal's 

(DECSC) 1/11 3/7 memory. 

• Cursor position 

• Visual character attributes 

• Character sets (GO, Gl, G2, or G3) 
currently in GL and GR 

• Wrap flag (autowrap or no autowrap) 

• State of origin mode (DECOM) 

• Selective erase attribute (DECSCA) 

• Any single shift 2 (SS2) or single 
shift 3 (SS3) functions sent 

Restores the terminal to the state 
saved by the save cursor (DECSC) 



Restore 


ESC 8 


cursor 


1/11 3/8 


(DECRC) 





VT300 REPORTS 229 



function. If nothing was saved by 
DECSC, then DECRC performs the 
following actions. 

• Moves the cursor to the home 
position (upper left of screen). 

• Resets origin mode (DECOM). 

• Turns all visual character 
attributes off (normal setting). 

• Turns selective erase attribute 
off. 

• Maps the ASCII character set into 
GL, and the DEC Supplemental 
Graphic set into GR. 



Notes on DECSC and DECRC 



• The terminal maintains a separate DECSC buffer for the main dis- 
play and the status line. This feature lets you save a separate oper- 
ating state for the main display and the status line. 

• DECSC does not save the protection attribute set by start protected 
area (SPA) and end protected area (EPA). 

WINDOW REPORTS (VT300 MODE ONLY) 

The host can ask the terminal how much of the current page is displayed on 
the screen at any time. The terminal responds by reporting how much of the 
page is on the screen, in terms of lines and columns. 

PROGRAMMING TIP: This operation is useful for applications that need to 
know the size of the current user window. 

Request Displayed Extent (DECRQDE) 

The host sends this control function to ask how much of the current page is 
displayed on the screen. The terminal responds with a report displayed extent 
(DECRPDE) sequence. 

CSI " v 

9/11 2/2 7/6 

Report Displayed Extent (DECRPDE) 

The terminal sends this control function in response to a request displayed ex- 
tent (DECRQDE) sequence. DECRPDE indicates how much of the current 
page is displayed on the screen for the active session. 

230 VT300 REPORTS 



Remember that the screen can be split into two user windows, one per session. 
The user can split the screen horizontally or vertically. DECRPDE indicates 
how much of the screen the active session has to display the current page. See 
Chapter 8 of Installing and Using the VT330/VT340 Video Terminal for details 
on user windows. 



CSI 


Ph 


; Pw; Pml; Pmt; Pmp 


// 


w 


9/11 


** 


3/11 ** ** 


2/2 


7/7 



where 



Ph is the number of lines of the current page displayed in the active ses- 
sion's window. 

Pw is the number of columns of the current page displayed in the active 
session's window. 

Pml is the number of the current page column displayed in the leftmost 
column of the active session's window. 

Pmt is the number of the current page line displayed in the top line of the 
active session's window. 

Pmp is the number of the current page displayed in the active session's 
window. 

USER-PREFERRED SUPPLEMENTAL SET (DECRQUPSS) 
(VT300 MODE ONLY) 

The host can ask for the current user-preferred supplemental set. The terminal 
responds with the assign user-preferred supplemental set (DECAUPSS) se- 
quence (Chapter 5). 

PROGRAMMING TIP: This operation is useful for applications that need to 
know what supplemental character set the terminal is using. 

Host Request (DECRQUPSS) 

The host requests the current user-preferred supplemental set by sending the 
following sequence. 

CSI & u 

9/11 2/6 7/5 



VT300 REPORTS 231 



Terminal Response 

The terminal uses the DECAUPSS device control string to report the current 
user-preferred supplemental set (Chapter 5). The terminal sends DECAUPSS in 
response to a DECRQUPSS sequence. The terminal can send one of the follow- 
ing reports. 

DCS ! u % 5 ST The user-preferred supplemental set is 

DEC Supplemental Graphic. 

DCS 1 ! u A ST The user-preferred supplemental set is 

ISO Latin-1 supplemental. 



232 VT300 REPORTS 



SUMMARY 

Table 12-5 lists all the sequences described in this chapter. 

Table 12-5 Sequences for VT300 Reports 

Name Mnemonic Sequence 

Primary Device Attributes 

Primary DA DA CS1 c or CS1 c 

request 

(Host to VT300) 



Primary DA 
response 
(VT300 to host) 



DA CSI ? Psc; Psl: ... Psn <• 

Psc = operati ig level. 
61 = level 1 (VT100 family). 

62,63 = level 3 (VT300 family) 



Psl. 


..Psn = extensions. 


1 


= 132 columns. 


2 


= printer port. 


3 


= ReGIS graphics. 


4 


= sixel graphics. 


6 


= selective erase. 


ri'" : '■'■'■■ 
1 


= soft character set. 


8 


= user-defined keys. 


9 


= NRC sets. 


13 


= lo< i' editing n'odo. 


15 


= DEC technical set. 


16 


= locator device port 


18 


= user windows. 


19 


= duai sessions. 



See Table 12-1 for alias responses. 



VT300 REPORTS 233 



Table 12-5 Sequences for V'1'300 Reports (Cont) 

Name MiiemomV Sixpimifv 



Secondary Device Attributes 

Secondary DA 

E)A request 
(Host to VT300) 



Secondary 
DA response 
(VT300 to host) 



DA 



Device Status Reports 

VT300 Operating Status 

Request DSR 

(Host to VT30G) 



Report 
(VT300 to host) 



DSK 



Cursor Position Report 

Request. DSR 

(Host to VT300I 



Report 
(VT300 to host) 



CPR 



CSI > c or CSI > c 



CSI > Pp;Pv;Pcc 

Pp = identification code. 

18 = VT330 terminal. 

19 = VT340 terminal. 

Pv = firmware version. 

Pc = ROM cartridge registration. 



CSI 5 n 

CSI n 

No malfunction. 

CSI 3 n 
Malfunction. 

CSI 6 n 

CSI PI: Pc R 

PI = line number. 

Pc = column number. 



234 VT300 REPORTS 



Table 12-5 Sequences for VT300 Reports (Cont) 

Name Mnemonic Sequence 

Extended Cursor Position Report 



Request 


DSR 


CSI ? 6 n 


(Host to VT300) 






Report 


DECXCPR CSI PI; Pc; Pp R 


(VT300 to host) 




PI = line number. 
Pc = column number. 
Pp = page number. 


Printer Status 






Request 


DSR 


CSI ? 15 n 


(Host to VT300) 






Report 


DSR 


CSI ? 13 n 


(VT300 to host) 




No printer. 

CSI ? 10 n 
Printer ready. 

CSI ? 11 n 

Printer not ready. 

CSI ? 18 n 
Printer busy. 

CSI ? 19 n 

Printer assigned to other session 



UDK Status (VT300 Mode Only) 

Request DSR 

(Host to VT300) 

Report DSR 

(VT300 to host) 



CSI ? 25 n 

CSI ? 20 n 
UDKs unlocked. 

CSI ? 21 n 

UDKs locked. 



VT300 REPORTS 235 



Table 12 5 Sequences for VT300 Reports (Cont) 

Name Mnemonic Sequence 

Keyboard Dialect 

Request DSR 

(Host to VT300) 

Report DSR 

IVT300 to host) 



Locator Device Status (VT300 Mode Only) 

Request DSR 

(Host to VT300) 

Report DSR 

( VT300 to host! 



CSI ? 


26 n 


CSI ? 


27; Pla: Pst n 


Pla 


= keyboard dialect. 


1 


= North, America p. 


2 


-British. 


3 


— Flemish. 


4 


= French Canadian 


5 


= Danish. 


6 


= Finnish. 


7 


= German. 


8 


= Dutch. 


9 


= Italian. 


10 


— Swiss FrencL 


11 


• Swiss German. 


12 


■ Swedish. 


13 


= Norwegian. 


14 


= French/Belgian 


15 


= Spanish. 


16 


= Portuguese. 


Pst 


= keyboard status. 





~ keyboard read]/. 


3 


= no keyboard. 


8 


= keyboard busy. 


de Or 


iy) 


CSI? 


55 n 


CSI? 


53 n 


No locator device. 


CSI? 


50 n 


Locator device ready. 


CSI? 


58 n 


Locat 


or device busy. 



236 VT300 REPORTS 



Table 12-5 Sequences for \T300 Reports (Cont) 

Name Mnemonic Sequence 

Locator Device ID (VT300 Mode Only) 



Request DSR 

(Host to VT300) 

Report DSR 

(VT300 to host) 



CSI ? 56 n 

CSI ? 57; n 
Unknown device. 



CSI ? 57; 1 n 

■-:"'■ v.; ■ .' V . :V ':: ; . : ' Digital's mouse, 

CSI ? 57; 2 n 
Digital's tablet. 

Terminal State Reports (VT300 Mode Only) 



Request 

(Host to VT300) 



Request color 
table report 



Terminal state 

report 

(VT300 to host) 

Color table 
report 

Restore 



DKCKQTSR CSIPsSu 

Ps = report requested. 

:.;■■■ :: : ■ .. :: ■ : ■ ." - ■ -': ignored. '■ ■ ■'.' . ■ 

1 = terminal state report. 

2 = color table report. 

DECRQTSR CSI 2; Ps2 $ u 

Ps2 = color coordinate system 

= HLS (default) 

1 = HLS 

2 = RGB 

DECTSR DCS 1 $ s D..D < checksums 1 and 2 > ST 
■ i; .;: I )...!) ■- . report data. ■ .'■■' ■ '■ 

DECCTR DCS 2 $ s D...D ST 

D...D = color data. (See text.) 

DEC RSTS DCS Ps $ p D...D ST 

■ . '■ ' Ps = data string format. ^-V ; : ^ 
■;: v ':■.':. = error. 

1 = terminal state report. 

2 = color table report. 

' : - [ X'^' : . ; ; ; D...D ■-■'■•■ restored data. 



VT300 REPORTS 237 



Table 12-5 Sequences for VT300 Reports (Cont) 

Name Mnemonic Sequence 

Presentation State Reports (VT300 Mode Only) 



Request 
(HosttoVT300l 



Cursor 

information 

report 

(VT300 to host! 

Tab stop report 
(VT300 to host) 

Restore 



DEC RQ PS Jt CSI Pa $ w 

Ps = report requested. 

:: s error." 

1 = cursor information report. 

2 = tab stop report. 

DECCIR DCS 1 $ u D...D ST 

D..D = data string. See text 
. for description. 

DECTABSR DCS 2 $ u D...D ST 
;; D...D = tab stops. 



I) EC RSI'S 



Mode Settings (VT300 Mode Only) 

Request: mode DECRQM 

(HosttoVT300l 



DCS Ps $ t D...D ST 

Ps = data string format. 

= error. 

1 = cursor information report. 

2 = tab stop report. 

D...D = data string. 



CSI Pa $ p 

Pa = ANSI mode. (Table 12-2) 

CSI ? Pd $ p 

Pd = DEC private mode. 
(Table 12-3) 



238 VT300 REPORTS 



Table 12-5 Se( 


juences for VT30 


Reports 


(Cont) 


Name 


Mnemonic 


Sequence 


Report mode 
(VT300 to host) 


DECRPM 


CSI Pa; 

Pa 


Ps$y 
= ANSI mode. (Table 12-2) 






Ps 



1 

2 

3 

4 


= mode state. 

= unknown mode. 

= set. 

= reset. 

— permanently set. 

= permanently reset. 


Set mode 


SM 


CSIPa 

Pa 


... Pa h 

= ANSI mode(s). (Table 12-2) 



Reset mode 



RM 



CSI ? Pd; ... Pd h 

Pd = DEC private mode(s). 
(Table 12-3) 

CSI Pa; ... Pa 1 

Pa = ANSI mode(s). (Table 1 2-2) 

CSI ? Pd; ... Pd 1 

Pd = DEC private mode(s). 
(Table 12-3) 



Control Function Settings (VT300 Mode Only 
DECRQSS 



Request 

(Host to VT300) 



Report 
(VT300 to host) 



DECRPSS 



DCS $ q D...D ST 

D...D — intermediate and/or final 
characters of function. 
(Table 12-4) 

DCS Ps $ r D...D ST 

Ps = 0, valid request. 
Ps =1, invalid request. 

D...D = intermediate and/or final 
characters of function. 
(Table 12-4) 



VT300 REPORTS 239 



Table 12-") Sequences for VT300 Reports (Cont) 

Name Mnemonic Sequence 

Saving and Restoring the Cursor State 

Save cursor DECSC ESC 7 '!:■:; // '' "A ■ ; ' ; 

state . 

Restore cursor OKCRC ESC 8 

state •'. .' -■'..'■' . ■.■'..; 

Window Report (VT300 Mode Only) 

Request ■ ' DECRQDE CSI " v 

(Host to VT3Q0) 

Report DECRPDE CSI Ph: Pw; Pml; Pmt; Pmp " w 

(VT300 to host) Ph = number of lines. 

3^'<: ; X;^ Pw = number of columns. 

Pml = first column at left. 

Pmt; = top line. 

Pmp ■- page number. 

User-Preferred Supplemental Set (VT300 Mode) 

Request DECRQUPSSCSI & u 

(Host to VT30G) 

Report DECAUPSS DCS () ! u % 5 ST 

(VT300 to host) DEC Supplemental Graphic 

DCS i 1 n A ST 

: ;: "{ : ':\ : :;;';': "■' : ; ;: - ; -':- '. 77 : : . ^ "■:<: r ; ; ' .■ /■ P^ ISO Latin-1 supplemental ; : 



240 VT300 REPORTS 



RESETTING THE TERMINAL 



13 



Soft Terminal Reset (DECSTR), 242 
Hard Terminal Reset (RIS), 244 

Using RIS with SSU Sessions, 245 
Tab Clear (TBC), 245 
Summary, 257 



This chapter describes how to reset the settings of many VT300 control func- 
tions at the same time. 

You can also reset your VT300 by using set-up. See Chapter 5 of Installing 
and Using the VT330/VT340 Video Terminal for information on using set-up. 

There are three control functions you can use to reset the terminal. 

Soft terminal reset Selects most of the power-up factory 

(DECSTR) factory default settings. 

Hard terminal reset Selects the settings stored in NVR 

(RIS) memory. 

Tab clear (TBC) Clears tab stops. 

Soft terminal resets and hard terminal resets affect many control functions, 
including some ANSI and DEC private modes. ANSI and DEC private modes 
are control functions that have only two settings, set or reset. 



241 



SOFT TERMINAL RESET (DECSTR) 

This control function changes most the terminal's current settings to the 
power-up default settings listed in Table 13-1. 

Available in: VT300 mode only 



CSI ! 

9/11 2/1 



P 

7/0 



You can also perform a soft terminal reset by selecting Reset Session in the 
Set-Up Directory screen. See Chapter 5 of Installing and Using the VT330/ 
VT340 Video Terminal. 

Notes on DECSTR 

• DECSTR affects only those functions listed in Table 13-1. 

• National replacement character set mode (DECNRCM) is not reset 
when you select Reset Session in set-up. 

Table 13-1 Soft Terminal Reset {DECSTR) States 



Mode 

Text cursor enable 

Insert/replace 

Origin 

Autowrap 

National replacement 
character set 

Keyboard action 

Numeric keypad 

Cursor keys 



Mnemonic 


State After DECSTR 


DECTCEM 


Cursor enabled. 


1RM 


Replace. 


DECOM 


Absolute (cursor origin at upper 




left of screen). 


DECAWM 


No autowrap. 


DECNRCM 


Multinational set. 


KAM 


Unlocked. 


DECNKM 


Numeric characters. 


DECCKM 


Normal (arrow keys). 



242 RESETTING THE TERMINAL 



Table 13-1 Soft Terminal Reset (DECSTR) States (Cont) 


Mode 


Mnemonic 


State After DECSTR 


Edit 


DECEDM 


Interactive. 


Edit key execution 


DECEKEM 


Immediate. 


Transmit execution 


DECTEM 


Immediate. 


Erasure 


ERM 


All characters. 


Guarded area transfer 


GATM 


All characters. 


Multiple area transfer 


MATM 


All selected areas. 


Selected area transfer 


SATM 


All areas. 


VT131 transmit 


DEC131TM 


On (VT131). 


Line transmit 


DECLTM 


Off (page or partial page). 


Transmit termination 


TTM 


Scrolling region. 


Other Control Functions 






Set top and bottom 
margins 


DECSTBM 


Top margin = 1. 

Bottom margin *= page length. 


All character sets 


GO, Gl, G2, 
G3, GL. GR 


VT300 default settings. 
(DECSTR works only in VT300 
mode.) 


Select graphic rendition 


SGR 


Normal rendition. 


Select character 
attribute 


DECSCA 


Normal (erasable by DECSEL 
and DECSED). 


Start selected area 
End selected area 


SSA 
ESA 


Cleared. 
Cleared. 


Start protected area 
End protected area 


SPA 
EPA 


Cleared. 
Cleared. 


Save cursor state 


DECSC 


Home position with 
VT300 defaults. 


Assign user-preferred 
supplemental set 


DECAUPSS 


Set selected in set-up. 


Select active status 
display 


DECSASD 


Main display (first 24 
lines). 



RESETTING THE TERMINAL 243 



HARD TERMINAL RESET (RIS) 

NOTE: Digital does not recommend using RIS to reset the terminal. You 
should use a soft terminal reset (DECSTR) instead. RIS usually causes a com- 
munication line disconnect and may change the current baud rate settings. The 
terminal waits a few seconds before it performs a received RIS function. 

This control function causes a nonvolatile memory (NVR) recall to occur. RIS 
replaces all set-up features with their saved settings. You can find out what the 
current saved settings are by looking at the Saved Settings column on the ter- 
minal's different set-up screens. See Chapter 5 of Installing and Using the 
VT330/VT340 Video Terminal. 

When performing a RIS, the terminal sends XOFF to the host to stop commu- 
nication. When the RIS is complete, the terminal sends XON to resume 
communication. 

The terminal stores these saved settings in NVR memory. The saved setting 
for a feature is the same as the factory-default setting, unless you saved a new 
setting. 

You can also perform a hard reset from the Set-Up Directory screen, by select- 
ing Recall Saved Settings. 

The RIS sequence is as follows. 

ESC c 

1/11 6/3 

RIS Actions 



Sets all features listed on set-up screens to their saved settings. 

Causes a communication line disconnect. 

Clears user-defined keys for both sessions. (See Chapter 14 for details 
on session management.) 

Clears the soft character set. 

Clears page memory. All data stored in page memory is lost. 

Clears the screen. 

Returns the cursor to the upper-left corner of the screen. 

Sets the select graphic rendition (SGR) function to normal rendition. 



244 RESETTING THE TERMINAL 



• Sets the independent protection attribute to not protected. 

• Selects the default character sets (ASCII in GL, and DEC 
Supplemental Graphic in GR). 

Using RIS with SSL) Sessions 

If you use use Digital's Session Support Utility (Chapter 14) to manage ses- 
sions, RIS does not disconnect communications. If SSU is enabled and at least 
one session is open, RIS does the following. 

• Erases the screen. 

• Moves the cursor to the home position. 

• Performs a soft terminal reset (DECSTR). 

• Resets the current session. 

TAB CLEAR (TBC) 

This control function clears tab stops. 



CSI Ps g 

9/11 3/? 6/7 



where 



Ps indicates the tab stops to clear. Ps has only two values, and 3. 
Default: Ps = 0. 

or none The terminal only clears the tab stop at the cursor. 

3 The terminal clears all tab stops. 



RESETTING THE TERMINAL 245 



SUMMARY 

Table 13-2 lists all the control functions described in this chapter. 
Table 13-2 VT300 Reset Sequences 

Name 

Soft terminal reset* 

Hard terminal reset 

Tabula ihm clear 



Mnemonic 


Sequence 


DECSTR 


CSIIp 


RIS 


ESCc 




Not recommended. 


TBC 


CSI g 




Clear tab at cursor position 




CSI 3 g 




Cit** jifl tabs. 



Available in VT300 node only. 



246 RESETTING THE TERMINAL 



PART 4 
DUAL SESSIONS 



SESSION MANAGEMENT 



14 



Dual Sessions, 249 

Two Ways to Manage Sessions, 250 

Session Resources, 252 

Independent Resources, 252 

Shared Resources, 253 
Multiple System Communications (MSC), 254 
Session Support Utility, 254 

SSU Environment, 254 

ANSI/ReGIS/Tektronix/VT52 Layer, 255 

SSU Layer, 255 
XON/XOFF Data Flow Control, 255 
Using SSU Software, 255 
Selecting Sessions (MSC or SSU Software), 255 
Enable Session Command, 256 



DUAL SESSIONS 

A session is an electronic connection between the terminal and a host system. 
The VT300 lets you run two sessions at the same time. Each time you estab- 
lish a connection with your host system from the terminal, you open a session 
on the terminal. 

Dual sessions let you process and view information from two sources at the 
same time. You can easily move back and forth between these sessions. You do 
not have to end one session before you begin another. You can run the two 
sessions on separate host systems or on the same system. 

The VT300 maintains a separate context for each session. What you do in one 
session does not affect the other session. 

249 



TWO WAYS TO MANAGE SESSIONS 

When you run two sessions at the same time, you need some way to manage 
the flow of data to and from each session. For example, suppose a user wants 
to switch from session 1 to session 2. The terminal must be able to inform the 
host system of the switch, without affecting the normal data flow. 

You can use one of two ways to manage sessions on a VT300. 

Multiple system communications (MSC) 
Session Support Utility 

Multiple system communications uses two communication lines between the 
terminal and host to run two sessions. Each session uses a separate line. You 
can connect the lines to the same host (or terminal server) or two separate 
hosts (or terminal servers). Figure 14-1 shows some typical MSC environments. 

MSC is basically a hardware solution for session management. MSC is the 
same type of system used by terminals that can run only one session. MSC 
does not require special programming commands. MSC session management is 
transparent to the host. The terminal manages each session locally. 

The Session Support Utility uses only one communication line to run two ses- 
sions. Usually, you use SSU software to run two sessions on the same host 
computer or terminal server. Figure 14-2 shows a typical SSU environment. 

SSU software uses a protocol of system-level commands to maintain dual ses- 
sions. You can use the commands that best suit your needs. 

SSU software differs from MSC in the following ways. 



SSU Software 

Uses one communication line 
for dual sessions. 

Uses a set of commands to 
control both sessions. 

Requires that the host and 
terminal recognize SSU 
commands. 



MSC 

Requires two communication 
lines, one for each session. 

Does not use commands. 



Is transparent to the host, 
since there are no commands 
to recognize. 



NOTE: Make sure your system supports SSU software before you use this pro- 
tocol. Your host system must be able to interpret and send SSU commands. 



250 SESSION MANAGEMENT 



The next section describes how the VT300 divides its resources between two 
sessions. The rest of the chapter describes the two methods of session manage- 
ment, MSC and SSU software. 



HOST 1 OR 
TERMINAL 
SERVER 



COMM LINE 1 (SESSION 1) 



HOST 2 OR 

TERMINAL 
SERVER 



COMM LINE 2 (SESSION 2) 




HOST OR 
TERMINAL 

SERVER 



COMM LINE 1 (SESSION 1) 



COMM LINE 2 (SESSION 2) 




MA 0087 86 



Figure 14-1 Typical MSC Environments 



SESSION MANAGEMENT 251 



HOST OR 

TERMINAL 

SERVER 



COMM LINE 



SESSION 1 
SESSION 2 




MA-0088-86 



Figure 14-2 Typical SSU Environment 

SESSION RESOURCES 

When you run dual sessions on the terminal, you interact with one session at a 
time. This active session has primary access to the terminal's features and re- 
sources. The inactive session must wait to use some resources. 

This section describes which resources each session can use independently and 
which resources they must share. 

Independent Resources 

The terminal maintains two sets of some features, so each session can use 
those features independently. For example, the terminal has two sets of page 
memory, one for each session. The terminal has two sets of the following 
features. 

• Page memory 

When you run dual sessions, each session has 72 lines by 80 or 132 
columns of page memory. 

• ANSI text state 

Each session maintains a record of current character sets, text attri- 
butes, and pages. 

• Status lines 

Each session has a status line. 



252 SESSION MANAGEMENT 



• Set-Up 

Each session has its own set-up feature settings. 

• Down-line-loadable character set 

You can design and load a soft character set for each session. 

• User-defined keys (UDKs) 

Each session can have a set of UDK definitions. However, the ter- 
minal can only store one set of definitions at a time. You can save 
the UDK definitions for the current session by using the UDK Set- 
up screen. If you do not save the definitions, they are lost when you 
turn off the terminal. 

• Communication lines 

In an MSC environment, each session has a communication line. 

• Graphics page memory 

Each session has a single page (800 x 480 pixels) for drawing 
images. 

• ReGIS state 

Each session maintains a record of the current ReGIS graphics 
state. 

• Tektronix 4010/4014 state 

Each session maintains a record of the current 4010/4014 state. 

• Color map (VT340) 

Each session has its own virtual color map. However, the terminal 
can only use the active session's color map. 

NOTE; If you change the active session's color map. the appear- 
ance of the inactive session's color is unpredictable. 

Shared Resources 

Only one session can use the following features at a time. If session 1 is using 
the resource, session 2 must wait until session 1 is finished. 

• Screen 

You can divide the screen to display data from two sessions at the 
same time. However, both sessions must compete for time to update 
the screen. See Chapter 8 of Installing and Using the VT330/VT340 
Video Terminal for details on dividing the screen into two windows. 

• Keyboard 

Only the active session can use the keyboard. 



SESSION MANAGEMENT 253 



• Printer port 

Only one session at a time can use the printer port. If session 1 is 
using the printer, session 2 must wait until session 1 is finished. 

You can assign the printer to a particular session by using set-up, or 
by using a print control function (Chapter 11). When you assign the 
printer port to a session, you restrict the use of the printer to that 
session. 

• Locator device port 

Only the active session can use the locator device (mouse or graph- 
ics tablet) to enter data. 

MULTIPLE SYSTEM COMMUNICATIONS (MSC) 

Multiple system communications lets you run two sessions without software 
support from the host. MSC uses both communication ports on the rear of the 
terminal, one port for each session. Each session has a dedicated physical link 
to the host. 

You can select MSC by using set-up. See Chapter 3 of Installing and Using 
The VT330/T340 Video Terminal. You cannot use MSC and SSU software at 
the same time. 

Unlike SSU software, MSC does not use a system-level protocol to maintain 
two sessions. MSC uses two hardwire links to the host. 

SESSION SUPPORT UTILITY 

SSU software lets the terminal run two sessions over a single communication 
line. That is, each session shares the same communication line. SSU is a set of 
system-level commands that the terminal and host use to maintain sessions. 

NOTE: Make sure your system supports SSU software before you use this pro- 
tocol. Your host system must be able to interpret and send SSU commands. 

SSU Environment 

The VT300 and the host system exchange different types of data at different 
levels, called layers. When you use SSU software, there are three basic layers 
of data exchange between the terminal and host. These layers have an order of 
priority, as follows. 

ANSI/ReGIS/Tektronix/VT52 layer 
SSU layer 
XON/XOFF flow control 



254 SESSION MANAGEMENT 



ANSI/ReGIS/Tektronix/VT52 Layer - This layer includes all alphanumeric char- 
acters as well as text and graphics functions the terminal uses. The alphanu- 
meric characters include all characters in the character sets that the terminal 
supports. Text functions include such tasks as selecting page format, character 
sets, and character attributes (for example, bold, underline, and protected attri- 
butes). Graphics functions include the drawing and coloring of images. 

SSU Layer - At this layer, the terminal and host exchange SSU commands to 
maintain the session environment. This layer connects the terminal to the host, 
and controls how the terminal and host switch from session to session. SSU 
software can also control the flow of data between the terminal and host at the 
session level. However, SSU data flow control is secondary to the XON/XOFF 
data flow control. 

XON/XOFF Data Flow Control - This layer controls the flow of data between 
the terminal and the host. When the terminal's receive buffer is full, this layer 
tells the host to stop sending data to the terminal. When the terminal's receive 
buffer can accept more data, this layer tells the host resume sending data to 
the terminal. 

This layer affects both sessions, because it controls the link between the termi- 
nal proper and the host. Appendix B describes XON/XOFF flow control in 
detail. 

Using SSU Software 

See Chapter 8 of Installing and Using The VT330/VT340 Video Terminal for 
details on using SSU session management. 

SELECTING SESSIONS (MSC OR SSU SOFTWARE) 

You can select the active session by using the Switch Session key or the enable 
session control function. 

If session 1 is the active session and you press Switch Session, session 2 be- 
comes the active session. Session 1 becomes the inactive session. If your host 
system also requires you to log in, you can log in to the second session. 

The enable session command works like the Switch Session key. If session 1 is 
the active session and the terminal receives the enable session command, ses- 
sion 2 becomes the active session. Session 1 becomes the inactive session. 



SESSION MANAGEMENT 255 



Enable Session Command 

This command works with MCS or SSU sessions. 

CSI & x 

9/11 2/6 7/8 

The session receiving the enable session command becomes the active session. 
The other session becomes the inactive session. 



256 SESSION MANAGEMENT 



VT52 MODE CONTROL CODES 



A 



Entering VT52 Mode, 257 
Exiting VT52 Mode, 258 



The VT52 mode lets the VT300 terminal operate like a VT52 terminal. You use 
VT52 mode with applications designed for the VT52. 

NOTE: VT52 mode may not be included in future Digital terminals. 
Programmers should only write new software for the ANSI operating mode. 
Software should avoid switching indiscriminately between ANSI and VT52 
modes. In VT52 mode, the terminal ignores many features and settings used in 
the ANSI environment. To avoid confusion, write all new software for the 
ANSI operating mode. 

Entering VT52 Mode 

You use the DECANM control function to change the terminal to the VT52 
mode of operation. In VT52 mode, the VT300 acts like a VT52 terminal. This 
mode lets you use applications designed for a VT52 terminal. 

CSI ? 2 1 

9/11 3/15 3/2 6/12 

Table A-l lists and describes all the escape sequences you can use when the 
terminal is in VT52 mode. 

Notes on DECANM 

• ANSI private control functions are not available. 

• The DEC Supplemental Graphic, ISO Latin-1 supplemental, and 
NRC sets are not available. 



257 



• Cl control characters are not available. 

• The ASCII character set defaults to GO. 

Exiting VT52 Mode 

You can exit VT52 mode by using the following escape sequence. 

ESC < 

1/11 3/12 

When you you exit VT52 mode, the terminal returns to the mode it was in 
before entering VT52 mode. 

Table A-l VT52 Escape Sequences 

Sequence Action 

ESC A Cursor up. 

ESC B Cursor down. 

ESC C Cursor right. 

ESC I ) '}:::Hi : Cursor left. :'.'-, ; ; . : . 

ESC F Enter graphics mode. ": : '\V '■ 

ESC G Exit graphics mode. 

ESC H Cursor to home position. 

ESC I Reverse line feed. 

ESC J Erase from cursor to end of screen. 

ES( K Erase from cursor to - : vd of line. 

ESC Y Pn Move curso; to column Pn. 

ESC Z Identify, (host to terminal) 

ESC / Z Report, (terminal to host) 

ESC = Enter alternate keypad mode. 

ESC > Exit alternate keypad (node. 

ESC < Exit VT52 mode. (Enter VT100 mode.) 

ESC * Enter autoprint mode. 

ESC _ Ex!:, ai itoprint :;..ode. 

ESC W Enter {winter controller roods. 

ESC X Exit printer controller mode. 

ESC] Print screen. 

ESC V Print the line with the cursor. 



258 VT52 MODE CONTROL CODES 



COMMUNICATION 



B 



Character Format, 260 
Making Connections, 260 

Modem Cables, 261 

Null Modem Cables, 261 

DECconnect Cabling for 6-Pin DEC-423 Connectors, 261 

Connecting the VT300 to Other Digital Products, 262 

Locator Devices, 262 
Communicating with Non-Digital Systems, 264 

Direct-Wired Connections, 264 

Connecting Through a Modem, 264 

Communicating with IBM Systems, 265 
VT300 Communication Ports, 265 

25-Pin RS232 Connector, 265 

25-Pin Signal Descriptions, 266 

DECconnect (DEC-423) 6-Pin Connectors, 269 

Comm 1 Port, 270 

Comm 2 Port and Printer Port, 270 
Modems, 271 

Low-Speed Modems, 271 

Medium-Speed Modems, 271 

High-Speed Modems, 271 

Worldwide Modem Protocols, 272 
Communications Set-Up Screen, 272 
Flow Control Features, 272 

Receive XOFF Point, 273 

Transmit Flow Control, 273 

Transmit Rate Limiting, 273 
Character Format Features, 274 



259 



Character Format, 274 
Stop Bits, 274 

Modem Features, 275 
Modem Control, 275 
Modem High Speed, 278 
Modem Low Speed, 278 
Disconnect Delay, 279 

Break, 279 

Break Key, 279 

Standards and Certification, 280 



This appendix describes how the VT300 communicates with a host computer, 
modem, or printer. The appendix lists the cables and modems you can use for 
different system configurations. The VT300 uses full-duplex, asychronous lines 
only. This appendix is important for users with special communication require- 
ments, particularly those having non-Digital systems. 

CHARACTER FORMAT 

The VT300 can send and receive characters in a 7-bit or 8-bit format. The 
asynchronous character format consists of a start bit (space), the data bits (1 = 
mark, = space), the parity bit (if present) and 1 or 2 stop bits (mark). The 
data bits represent a character, with the least significant bits leading. 

You can set the parity bit to none, odd, even, space, or mark, using the 
Character Format feature in the Communications Set-Up screen. 

For more information on the asynchronous character format, see ANSI 
X3.15-1976, "American National Standard for bit sequencing of the American 
National Standard Code for Information Interchange in Serial-By-Bit Data 
Transmission". 

MAKING CONNECTIONS 

You can order EIA cables from Digital in a variety of lengths, for flexible sys- 
tem configuration and expansion. Digital cables provide a minimum shielding 
effectiveness of 30db in the 30 through 200 MHz range. You can use these 
EIA cables for traditional null modem, modem, and 25-conductor EIA applica- 
tions. You can also use EIA cables 

• with Digital's DHU11, DHV11, DMZ32, DMF32, and DZSll inter- 
face devices. 



260 COMMUNICATION 



• with terminals and modems. 

• as part of the FCC upgrading process for traditional products, such 
as Digital's DZ11 and DMR11 modules. 

Modem Cables 

The BC22E modem cable uses 16 conductors. The cable has a 25-pin plug on 
one end and a 25-pin socket on the other. You can use the BC22E cable as 

• a connection between the 25-pin RS232 port on the VT300 and any 
of Digital's modems (such as the DF03 and DF224). 

• a serial line extension cord. 

• a direct connection between the VT300 and many of Digital's com- 
munication options. 

The BC22E cable is available in the following lengths. 

BC22E-10/AB 10 feet BC-22E-100/AB 100 feet 

BC-22E-25/AB 25 feet BC-22E-200/AB 200 feet 

BC-22E-50/AB 50 feet BC-22E-250/AB 250 feet 

When style is an issue, you can use the BCC14 cable. 

BCC14-10/AB 10 feet 
BCC14-25/AB 25 feet 
BCC14-50/AB 50 feet 

Null Modem Cables 

The BC22D null modem cable has 16 conductors, and a 25-pin socket on both 
ends. This cable is available in the following lengths. 

BC22D-10/AB 10 feet BC22D-100/AB 100 feet 

BC22D-25/AB 25 feet BC22D-200/AB 200 feet 

BC22D-50/AB 50 feet BC22D-250/AB 250 feet 

DECconnect Cabling for 6-Pin DEC-423 Connectors 

The VT300 has 6-pin DEC-423 connectors to take advantage of DECconnect 
terminal cabling. Based on the RS423 standard, DEC-423 cabling lets you run 
your terminal at higher speeds and over longer distances than the RS232 stan- 
dards. Where RS232 signaling limits cable runs to 50 feet, DEC-423 lets you 
use cable runs of up to 1000 feet from the terminal to the host system. 

COMMUNICATION 261 



DEC-423 provides enhanced electrical overstress (EOS) and electrostatic dis- 
charge (ESD) protection that reduces computer equipment damage from static 
discharge, lightning, or ac power impulse. 

Adapters and converters are available that let you use DEC-423 and the new 
DECconnect office cabling with older terminals, personal computers, and 
printers. 

The DECconnect office cable is a 6-conductor flat cable used to connect the 
VT300 to the DECconnect wallplate. Each end of tne office cable has Digital's 
proprietary MMP (modified modular plug). The plug is similar to the modular 
plugs used in telephone equipment, but is modified to prevent accidental con- 
nection of the DEC-423 cable into the phone jack. 

The following DECconnect cables, adapters and converters are available. 

BC16E-10/DA 10 foot DECconnect office cable 

BC16E-25/DA 25 foot DECconnect office cable 

BC16E-50/DA 50 foot DECconnect office cable 

H8572 Extender with MMJ on both ends 

H8571-A MMJ to DB-25S adapter 

H8571-B MMJ to DB-9S adapter 

H3 105 Active converter — RS232 to DEC-423 

To extend your DECconnect connection, you can use the following 
configuration. 

[TERMINAL]<— BC16E— >[H8572]<— BC16E— >[HOST SYSTEM] 

Connecting the VT300 to Other Digital Products 

Table B-l lists the cables to use when connecting the VT300 to a terminal 
server, modem, or statistical multiplexer. Table B-2 lists the cables and adapt- 
ers to use when connecting the VT300 to a printer. 

Locator Devices 

The VT300 has a 7-pin locator device connector on the rear of the terminal. 
The connector supports a locator device (mouse or graphics tablet). The VT300 
supports the following Digital locator devices. 

VSXXX-AA mouse VSXXX-AB graphics tablet 



262 COMMUNICATION 



Table B-l Cables to Terminal Servers, Modems, and Statistical Multiplexers 



To Connect the VT300 to... 

Terminal Servers 
DECS A (LAT-11) 
DSRVA-AA/DA (DECserver 100) 

Statistical Multiplexers 
DFM04-AA/AB DFM 1 2-AA/AB 

DFM08-AA/AB DFM16-AA/AB 

■VAX Systems 
OMF32 '' . 
DMZ32-M/AB 

n/32 

PDP-11 Unibus Systems 

DHU11 

DZ11 

DL11 

PDP-11 Q-bus Systems 
DHV11 DLV.J] 

DZQ11 DZV11 

DLVE1 



Modems 




DF112-AA 




DF124-AA 




DF224-AA 




Table B-2 


Cables to Digital P 


Printer 


Cable/Adapter 


LA12 


BC16E-10/DA 


LA50 


H8571-A 


LA210 




LA75 


BC16E-10/DA 


LN03 series 


BC16E-10/DA 




HS571-A 


LQP series 


BC16E-10/DA 




H8571-A 



Use This Cable... 
BC22D 

BC22E, BCC04, or BCC14 

BC22D 

BC22D 



BC22D 



BC22E 



Description 

10 foot DECconnect office cable 
MMJ to DB-25S adapter 

10 foot DECconnect office cable 

10 foot DECconnect office cable 
MMJ to DB-25S adapter 

10 foot DECconnect office cable 
MMJ to DB-25S adapter 



COMMUNICATION 263 



COMMUNICATING WITH NON-DIGITAL SYSTEMS 

This section describes how to use the VT300 with non-Digital environments. 

The most conservative approach to communicating with a non-Digital system is 
to use the 25-pin RS232 serial port with a suitable cable and recall the factory- 
default settings from set-up. Then set the following features in set-up. 



Set-Up Screen 


Feature 


Setting 


Global Set-Up 


On-Line/Local 


on-line 


General Set-Up 


Terminal Mode 


VT100 




Device Attributes Response 


VT100 


Display Set-Up 


Scrolling 


jump 


Communications Set-Up 


Transmit Speed 


(Match your host.) 




Receive Speed 


receive = transmit 




Receive XOFF Point 


(Match your host.) 




Transmit Flow Control 


disabled 




Character Format 


(Match your host.) 




Stop Bits 


(Match your host.) 




Disconnect Delay 


no disconnect 




Local Echo 


disabled 



Keyboard Set-Up 



Compose 



disabled 



You select the Character Format in the Communications Set-Up screen. Digital 
recommends that you try the 7-bit settings first, starting with "7 bits, mark 
parity". For speeds above 110 bits per second, select 1 stop bit. For a speed of 
110 or lower, select 2 stop bits. 

Direct-Wired Connections 

Follow these basic rules to make a direct-wired connection to a non-Digital 
host. 

1. Match the terminal's baud rate to that of your host. If you are 
unsure, try 9600 baud first and work down. 

2. Match the terminal's character format to that of your host. If you are 
unsure, try "7-bits, mark parity". 

Connecting Through A Modem 

Follow these basic rules to connect to a non-Digital host via a modem. 

1. Match the terminal's baud rate with that of your modem. If you are 
unsure, try 300 baud first and work up. 

264 COMMUNICATION 



2. Match the terminal's character format with that of your modem. 

3. Set the Transmit Flow Control feature in the Communications Set-Up 
screen to "disabled". 

4. Set the Receive XOFF Point feature in the Communications Set-Up 
screen to "never". 



Steps 3 and 4 ensure that the VT300 receives some characters without halting 
after receiving an XOFF from the host. Character processing in the VT300 oc- 
curs at about 9400 bits per second. To prevent data loss, set the terminal's 
transmit and receive rates lower than 9400 bits per second to prevent data 
loss. With this configuration, you cannot use the Hold Session or Local Print 
functions. 

Communicating with IBM Systems 

Some IBM systems do not echo characters back to the terminal screen. These 
systems generally operate in half-duplex environments. If the characters that 
you type do not appear on the screen, check to make sure the host is operating 
correctly. If it is, set the Local Echo feature in the Global Set-Up screen to 
"enabled". 

The VT300 communicates asynchronously and generally conforms to ANSI 
X3.64 environments only. It does not support IBM traits such as 3270 emula- 
tion, SNA, Bisync, SDLC, or HDLC. 

VT300 COMMUNICATION PORTS 

The VT300 has two communication ports, Comml and Comm2. The Comml 
port has two connectors, a 25-pin RS232 connector and a 6-pin DEC-423 con- 
nector. The Comm2 port has one 6-pin DEC-423 connector. Only one port is 
active at a time. You use the Global Set-Up screen to select which port is 
active. 

25-Pin RS232 Connector 

This DB25 serial port accepts a variety of modems meeting national and inter- 
national standards. Table B-3 lists the signals for the 25-pin RS232 connector. 
The voltages acceptable at this port comply with EIA standard RS423, 
"Electrical Characteristics of Unbalanced Voltage Digital Interface Circuits". 



COMMUNICATION 265 



Table B-3 


EIA Interface Signals for the 25-Pin RS232 Connector 










Circuit 


Pin 


Source 


Name 


Function 


CCITT/EIA/DIN 


1 


Not used 








2 


VT300 


TXD 


Transmitted data 


103/BA/D1 


3 


Modem 


RXD 


Received data 


104/BB/D2 


4 


VT300 


RTS 


Request to send 


105/CA/S2 


5 


Mode 


CTS 


Clear to send 


106/CB/M2 


6 


Modem 


DSR 


Data set ready 


107/CC/M1 


7 


— 


SGND 


Signal ground 


102/AB/E2 


8 


Modem 


RLSD 


Receive line 
signal detector 


109/CF/M5 


9 to 11 


Not used 








12 


Modem 


SPDI 


Speed mode indicator 


112/CI 


13 to 19 


Not used 








20 


VT300 


DTR 


Data terminal ready 


108.2/CD/S1.2 


21 to 22 


Not used 








23 


VT300 


SPDS 


Speed select 


111/CH/S4 


24 to 25 


Not used 









25-Pin Signal Descriptions 

Transmitted Data — TXD (Pin 2 BA/103/D1) 

Data on this circuit represents the serially encoded characters that the VT300 
transmits. This circuit is at mark state (-) during stop bits between characters, 
and when data is not being transmitted. This signal is also supported on the 
6-pin DEC-423 connectors. 

Received Data — RXD (Pin 3 BB/104/D2) 

Data on this circuit represents the serially encoded characters the VT300 re- 
ceives. This signal is supported on the 25-pin RS232 and 6-pin DEC-423 
connectors. 

In modem control mode 1 (Communications Set-Up), the terminal ignores re- 
ceived characters if RLSD is unasserted. This is an implementation of mark 
carrier clamping. 



266 COMMUNICATION 



In modem control mode 2, the terminal receives characters even if RLSD is 
unasserted. This implementation permits use of V.25 bis compatible autodial 
modems in modem control mode 2. You do not have to set modem control 
mode to "disabled" to access the autodial functions. 

When mode control mode is disabled (data leads only), the terminal processes 
received data regardless of the state of the control lines. 

Request To Send — RTS (Pin 4 CA/105/S2) 

Asserting RTS may put the modem in the transmit mode. In transmit mode, 
the modem asserts CTS. When the terminal is in local mode, RTS is deas- 
serted. This signal is not supported on the 6-pin DEC-423 connectors. 

NOTE: On full-duplex modems without RTS inputs, CTS is asserted by the 
modem whenever it is ready for transmission. 

Clear To Send — CTS (Pin 5 CB/106/M2) 

The modem asserts CTS when it is ready to receive data. This signal is not 

supported on the 6-pin DEC-423 connectors. 

The data can be in one of two forms: a command to the modem if off-line (DSR 
deasserted), or transmitted data to the host if on-line (DSR asserted). 

Data Terminal Ready — DTR (Pin 20 CD/108.2/S1.2) 

The VT300 asserts DTR whenever it is ready to send or receive on the active 

port. Asserting DTR allows a modem to connect and maintain the connection. 

Deasserting DTR prevents the modem from completing a started call, and 

causes an already established call to disconnect. A deassertion of 50ms causes 

a disconnect to occur. This signal is also supported on the 6-pin DEC-423 

connectors. 

With auto-answer modems, the terminal must assert DTR before the modem 
can answer a call. If DTR is deasserted, the modem does not answer the call. If 
a connection exists, DTR remains asserted whether the terminal is on-line, lo- 
cal, or making the transition. Switching between on-line and local modes does 
not cause a disconnect. 

The VT300 drops DTR when one of the following functions is performed. 

Recall Saved Settings (Set-Up Directory) 

Recall Factory Default Settings (Set-Up Directory) 

Shift-Break 

Power-up self-test 

Hard terminal reset (RIS) 



COMMUNICATION 267 



Data Set Ready — DSR (Pin 6 CC/107/M1) 
Asserting DSR indicates 

• the modem is in data mode and connected to the communications 
channel; 

• the answer tone is finished, and you are being charged by the PTT; 

• the modem is ready to exchange control signals in order to begin 
data transmission and reception. 

This signal is also supported the 6-pin DEC-423 connectors. 

If DSR becomes unasserted before DTR during a call, the terminal disconnects 
the call. The terminal considers any new assertion of DSR a new call. If (1) the 
VT300 is connected to a modem that is off, or (2) DSR becomes an open cir- 
cuit, then the terminal interprets the condition as a deassertion. You can check 
the state of the DSR input on the indicator status line. 

If DSR is deasserted 220 ms after DTR is deasserted, the VT300 does nothing 
because the modem has already disconnected. 

If DSR is still asserted 220 ms after DTR is deasserted, DTR from the VT300 
remains deasserted for at least 2 seconds to assure that the modem is 
disconnected. 

When DSR is unasserted and modem control mode 2 is selected, an off-line 
state exists. (See "Modem Control Mode 2" in this appendix.} In this state, 
you can interact with an intelligent modem for such actions as entering phone 
numbers and changing modem set-up. 

When DSR is asserted in modem control mode 2, the modem, terminal, and 
host system are ready for communication to a remote host. 

Receive Line Signal Detector — RLSD (Pin 8 CF/109/M5) 
This signal is also called carrier detect. The modem asserts RLSD when the 
received signal is of sufficient amplitude. This signal is not supported on the 
6-pin DEC-423 connectors. 

The unasserted condition of RLSD indicates (1) there is no received signal, or 
(2) the signal is unsuitable for demodulation. 

Speed Indicator — SPDI (Pin 12 CI/112/M4) 

This signal comes from the modem. SPDI lets modems control the terminal's 

transmit and receive rates. This signal is not supported on the 6-pin RS423 

connector. 



268 COMMUNICATION 



7/ modem control mode 1 or 2 is enabled (Communications Set-Up) 

If SPDI is unasserted, the terminal's transmit and receive speeds are set to the 

current Modem Low Speed setting in Communications Set-Up. 

If SPDI is asserted, the transmit and receive speeds are set to the current 
Modem High Speed setting in Communications Set-Up. 

Table B-4 shows common settings for a wide variety of modems. 



Table B-4 


Common Speed Settings Foi 




SPDI 


SPDI 




Asserted 


Unasserted 


AT&T 212 


1200 


300 


AT&T 103 


300 


n/aor HO 


V.22 


1200 


600 


V.22 bis 


2400 


1200 


V.26 ter 


2400 


1200 


V.32 


4800 


2400 


V.32 


9600 


4800 



Speed Select — SPDS (Pin 23 CH/111/S4) 

SPDS comes from the terminal. If the VT300's baud rate is greater than or 
equal to 1200, the speed select rate is high. If the baud rate is less than 1200, 
the speed select rate is low. 

When this signal is enabled at the modem, the terminal can select modem 
speed by controlling EIA pin 23. 

NOTE: The DF224 modem is factory-set to ignore this pin and make the termi- 
nal receive speed information from the speed indicator signal (SPDI 12/CI/112I 
M4). 

DECconnect (DEC-423) 6-Pin Connectors 

The 6-pin connectors for Comml and Comm2 provide limited modem support. 
The DTR output and DSR input are supported on this connector. Transmit 
ground for transmit data and DTR is isolated from receive ground used for 
receive data and DSR. 

Using Modems on DEC-423 Connectors 

The DEC-423 connector does not support the following signals: RTS, CTS, 
RLSD, SPDI, and SPDS. Because these signals are not supported, you cannot 
use the modem control modes (Communications Set-Up). When running a mo- 
dem on the 6-pin connector, set modem control mode to "disabled". 

COMMUNICATION 269 



DEC-423 Signals 




Pin Signal Name 


Mnemonic 


1 Data terminal ready* 


DTR (ready out) 


2 Transmitted data* 


TXD (TX + ) 


3 Transmitted data return 


(TX-) 


4 Received data return 


(RX-) 


5 Received data* 


RXD (RX +) 


6 Data set ready* 


DSR (ready in) 



* See the signal description for the 25-pin RS232 connector. 

Pin 6 is on the right end of the connector, above the locking tab. 
6-Pin Connector (tab facing down) 



12 3 4 5 6 



Comm 1 Port 

The host 1 port has a 25-pin RS232 connector and a 6-pin DEC-423 connector. 
You can connect a communication line to each connector. Then you can use the 
Comml Port feature in Global Set-Up to switch between full modem control 
support ("RS232" setting) and DECconnect ("DEC-423" setting). 

This port supports communication speeds of 75, 110, 150, 300, 600, 1200, 
2400, 4800, 9600 (the default), and 19,200 bits per second. You can use differ- 
ent transmit and receive speeds. 

If you switch from RS232 (25-pin port) to DEC-423 (DECconnect), the VT300 
disconnects the RS232 port. If you switch from DEC-423 to RS232, the VT300 
disconnects the DEC-423 connector (deasserting DTR). 

Comm 2 Port and Printer Port 

These ports work the same as the Comm 1 DEC-423 connector. They support 
the same communication speeds (9600 default). 

Comm 2 lets you transmit and receive at different speeds. The printer port 
does not. Use only the " Receive = Transmit" setting for the printer port. 



270 COMMUNICATION 



MODEMS 

The VT300 supports asynchronous, full-duplex modems. The VT300 does not 
support half-duplex modems or synchronous modems. 

Low-Speed Modems (300 to 1200 Baud) 

In low-speed communication, 1200 baud is now a more common speed than 300 
baud. Digital's DF03 and DF112 modems support 1200 baud communication. 

The standard protocols for 1200 baud communication are AT&T 212A in North 
America, and CCITT V.22 in Europe and Japan. The two protocols are not 
compatible at the modulation level. The Racal Vadic 3400 protocol is also in 
use and may be less susceptible to noisy line environments. Most data center 
modems that use the Racal Vadic protocol also support AT&T 212A. These 
three protocols are full duplex and work over ordinary phone lines. 

The standard protocols for to 300 baud communication are AT&T 103 in 
North America, and CCITT V.21 in Europe and Japan. These protocols are not 
compatible at the modulation level. 

Medium-Speed Modems (2400 Baud) 

The worldwide standard protocol for 2400 baud communication is CCITT V.22 
bis. This protocol is full-duplex over dial-up phone lines. It adjusts to both the 
sending and receiving characteristics of the line conditions at the beginning of 
communication. The V.22 bis protocol requires much cleaner, noise-free tele- 
phone lines than 1200 baud protocols. Many long-distance circuits cannot sup- 
port communication at 2400 baud using V.22 bis. 

V.22 bis modems are supposed to use the 1200 baud V.21 protocol if the line is 
too noisy, but some units may not. If you want to connect at 1200 baud with a 
V.22 bis modem, you must determine whether it is set for AT&T 2 12 A or V.22 
bis. 

High-Speed Modems (Over 2400 Baud) 

The CCITT V.26 ter protocol also runs at 2400 baud. This protocol is techni- 
cally different from V.22 bis and handles noisier phone lines. V.26 ter is also 
much more expensive, using echo canceling rather than frequency division mul- 
tiplexing for full-duplex operation. V.26 ter modems are more compatible with 
the higher speed V.32 4800 and 9600 baud modems and could be a better in- 
vestment in the long run. 



COMMUNICATION 271 



Worldwide Modem Protocols 

Table B-5 shows many modem protocols used throughout the world. 
Table B 5 Worldwide Modem Protocols ' 









Duplex 










Modem 


Bits/ 


True 


Full/ 




A sync, 


Dial-up/ 




Protocol 


Second 


Rate 


Half 


MM 


Syne 


Leased 


Area 


AT&T 
















103 


300 


300 


F 


FSK 


A 


D 


North America 


201 


2400 


1200 


11 


PSK 


S 


D/L 


North America 


202 


1200 


300 


II 


— 


A 


I) 


North America 


208 


4800 


1600 


H/F* 


PSK 


S 


D/L 


North America 


209 


9600 


2400 


H/F* 


— 


S 


L 


North Amerirji 


212A 


1200 


600 


F 


PSK 


A/S 


D 


North America 


CCITT 
















V.21 


300 


300 


F 


FSK 


A 


D 


Europe. Japan 


V.22 


1200 


600 


F 


QAM 


A/S 


D 


Europe. Japan 


V.22 bis 


2400 


600 


F'. ■ 


QAM 


A-'S 


D 


world 


V.23 


1200 


600 


F 


PSK 


A/S 


D 


Europe, Japan 


V.26 ter 


2400 


1 200 


F 


— 


A/S 


D 


world 


V.29 


9600 


2400 


H/F* 


— 


S 


D/L 


world 


V.32 


4800 


2400 


F 


— 


A/S 


D 


world 



. * 2/4 wire . . ... . . 

COMMUNICATIONS SET-UP SCREEN 

Chapter 5 of Installing and Using the VT330/VT340 Video Terminal describes 
the features you can set from the Communications Set-Up screen. The follow- 
ing sections provide more details about some of the features that affect data 
flow control, character format, and modems. 

FLOW CONTROL 

The VT300 can operate at transmission speeds of up to 19,200 baud. However, 
the terminal may not be able to keep up with the incoming data. The terminal 
stores incoming characters in its 1024 byte receive buffer, and processes them 
on a first-in/first-out basis. 



272 COMMUNICATION 



When the buffer begins to fill, the terminal sends an XOFF (DC3) signal to the 
host. This signal tells the host to suspend its transmission to the terminal. 
When the host stops transmitting, the terminal processes most of the charac- 
ters in of the receive buffer. When the buffer is nearly empty, the terminal 
sends an XON (DC1) signal to the host to resume transmission. 

Receive XOFF Point 

Values: 64 (default), 256, 512, never 

64 (default), 256, 512 

The VT300 sends XOFF to the host when its input buffer contains 64, 256, or 
512 bytes. The terminal stores all received characters except NUL, XON, and 
XOFF in the input buffer before further processing. NUL is discarded. 

There are three XOFF points and one XON point. 

Never 

The VT300 temporarily stores all characters except NUL in the input buffer 
before further processing. NUL is discarded when received. The host system 
must prevent overflow of the input buffer. 

Operating systems that do not recognize XON/XOFF signals can send fill char- 
acters. The only valid fill character is NUL (hexadecimal, decimal, or octal). 

Transmit Flow Control 

Values: XON/XOFF (default), disabled 

When you select XON/XOFF, the VT300 recognizes received XON and XOFF 
characters from the host. When the terminal receives XOFF, it stops sending 
any codes except XOFF and XON. The Wait indicator on the keyboard also 
turns on. The terminal resumes transmission when it receives XON. 

If you select the disabled setting, pressing Ctrl-S sends XOFF and pressing 
Ctrl-Q sends an XON. 

Transmit Rate Limiting 

When you enable this feature, the VT300 limits the rate at which it sends data 
to the host to 150 to 180 characters per second, with even spacing. Some host 
systems can only keep up with the relatively slow input of keys typed manually 
from the keyboard. Rate limiting simulates this condition and reduces the inter- 
rupt burden on the host. 

When disabled, the terminal sends all messages and keystrokes as fast as pos- 
sible, limited only by the current Transmit Speed setting. 

COMMUNICATION 273 



DECXRLM Control Function 

Software can control the Transmit Rate Limiting feature through the 

DECXRLM control function. DECXRLM has two settings. 



Set (limited) 


CSI 

9/11 


? 
3/15 


7 

3/7 


3 
3/3 


h 
6/8 


Reset (unlimited) 


CSI 

9/11 


? 
3/15 


7 
3/7 


3 

3/3 


1 

6/12 



CHARACTER FORMAT FEATURES 

You can select the character format and number of stop bits in the 
Communications Set-Up screen. 

Character Format 

Values: 

8 bits, no parity (default) 7 bits, no parity 

8 bits, even parity 7 bits, even parity 

8 bits, odd parity 7 bits, odd parity 

8 bits, even, no check 7 bits, mark parity 

8 bits, odd, no check 7 bits, space parity 

7 bits, even, no check 

7 bits, odd, no check 

If you select a "no check" setting, the VT300 ignores the receive parity bit. 

If you enable parity error detection, the terminal converts characters with re- 
ceived parity errors to the SUB character. This character appears on the 
screen as an error indication (backward question mark). 

If you select 8 data bits, the eighth bit is when you use 7-bit character sets. 
In this case, the terminal ignores the bit when received. 

Stop Bits 

You can specify 1 or 2 stop bits with any of the available baud rates or data 
bit/parity combinations. This feature is required for asynchronous terminals 
connected to data networks as specified in CCITT recommendations X.20bis. 

As a general rule, use 2 stop bits for baud rates below 300. Otherwise, use 1 
stop bit. 



274 COMMUNICATION 



MODEM FEATURES 

Modem Control 

Values: disabled (data leads only, default) 
mode 1 (VT220) 
mode 2 

This feature selects how the VT300 uses modem control signals. 

Disabled (Data Leads Only) 

The terminal ignores all modem control signals, and communicates using the 

data leads only. 

DTR is always asserted except when you initiate a disconnect 

sequence. RTS is always asserted. The terminal ignores DSR, CTS, RLSD and 

SPDI. 

Modem Control Mode 1 (VT220) 

Included for compatibility with the VT220, this mode requires the handshake 
exchanges of DTR/DSR, and CTS/RTS before any data transmission or recep- 
tion begins. 

Connection 

The VT300 waits for the exchage of DTR/DSR and RTS/CTS. 

If the Auto-Answerback feature is enabled, the terminal sends the answerback 
message after the assertion of DSR, CTS, and RLSD. CTS is the last line 
checked. 

After making a connection, the VT300 performs the following operations to en- 
sure that it is ready to send and receive. 

1. Unlocks the keyboard, if it is locked. 

2. Clears any transmit in progress on the active port. 

3. Clears all buffers associated with the active port. 

4. Clears the "XOFF sent" and "XOFF received" state of the active 
port. 

After receiving the carrier tone, the modem asserts CD, and data transmission 
and reception can begin. 



COMMUNICATION 275 



Disconnection 

A disconnect sequence begins when any of the following events occur. 

• You press Shift-Break. 

NOTE: You can disable the Break key in the Keyboard Set-Up 
screen. 

• You select Recall Saved Settings, or Recall Factory Default Settings 
from the Set-Up Directory. This disconnects the active session's 
line. 

• You turn off the terminal. 

• The VT300 loses the DSR, CTS, or RLSD signal. 

• After establishing a connection on the Comml 25-pin line, the 
VT300 loses the RLSD for longer than 2 seconds (or 60 ms). 

In modem control mode 2, RLSD (CD) is ignored. 

• The VT300 receives a hard terminal reset (RIS). 

Modem Control Mode 2 

In this mode, there are two operating states for the modem, "Off Line" and 
"On Line". The modem indicates which mode is current on the status line with 
the DSR indicator. If DSR is unasserted, then the modem is off-line. 
Otherwise, it is on-line. 

The VT300 only supports the hardware handshaking of the V.25 bis protocol. 
The VT300 hardware does not support the ring indicator (RI) signal. The termi- 
nal does not support those states in which a transition is based on the RI 
signal. 

Also, the VT300 does not parse the commands shown in CCITT Table 3/V.25 
bis. The modem must parse these commands. 



276 COMMUNICATION 



VT300 V.25 Bis State Diagram 



VT300 STATE 
STATE #1 
DTE_NOT_READY 
DTR=OFF DSR=OFF 
CTS=OFF 



VT300 STATE 1 
STATE #2 
DTE_READY 
DTR=ON DSR=OFF 
CTS=OFF 



VT300 STATE 


2 


STATE #'c 


( 




DTE-DCE 


DIALOG 


DTR=ON 


DSR= 


=OFF 


CTS=ON 







VT300 STATE 2 
STATE #4 
CALL_ESTABLISH 
DTR=ON DSR=OFF 
CTS=ON 



VT300 STATE 3 
STATE #5 
ANSWER_TONE DET 
DTR=ON DSR=OFF 
CTS=OFF 



VT300 STATE 4 
STATE #6 
CALL_CONNECTED 
DTR=ON DSR=ON 
CTS=OFF 



VT300 STATE 4 
STATE #12 
DATA_TRANSFER 
DTR=ON DSR=ON 
CTS=X 



VT300 V.25 Bis Connection 



DTE 
DCE 
DTR 
DSR 
CD: 



-<D CRQ<cr»- 



-<H <XON»- 



-<E Ready<crlf»- 



-<K Attached<crlf»- 



RTS:. A 



CTS: B 



(A) Power-up. The terminal asserts RTS when power is applied. 

(B) The modem asserts CTS. 

(C) Self-test has completed. The terminal asserts DTR. 

(D) You type CRQ (Call Request) from keyboard, or press a previously loaded 
UDK. 

(E) The modem receives and parses this character string. 

(F) The modem deasserts CTS. 

(G) The modem asserts DSR. 
(H) The modem asserts CD. 
(I) The modem asserts CTS. 

(J) The terminal sends an XON. 



COMMUNICATION 277 



VT300 V.25 Bis Disconnection 

DTE:-<A logoff > 



DCE: <B logged out at > <G Disconnected- 
CD : c 



DSR 
CTS 
DTR 



D_ 



(A) You log off the system. 

(B) The host sends (and VT300 displays) the log off message. After the log 
off message, the host starts a disconnect procedure. 

(C) The modem deasserts carrier detect, (computer hangs up). 

(D) The modem deasserts DSR. 

(E) The modem deasserts CTS. 

(F) As a result of the modem dropping DSR, the terminal drops DTR. 

(G) The modem sends the message "Disconnected" to the terminal. 

(H) The minimum DTR deassertion time has been met. The terminal asserts 

DTR. 
(I) The modem asserts CTS. 

Modem High Speed 

Values: ignore (default), 300,600,1200,2400,4800,9600,19.2K 

When you enable modem control, the VT300 can use the speed indicator signal 
(SI) from the modem to select the communication rate. The Modem High Speed 
feature sets the rate used when the speed indicator line is "on". 

If you set this feature to "ignore", the terminal uses its regular transmit and 
receive speeds. 

Modem Low Speed 

Values: ignore (default), 300,600,1200,2400,4800,9600,19.2K 

This feature is similar to the Modem High Speed feature, but sets the commu- 
nication rate when the speed indicator line is "off". If you set Modem Low 
Speed to "ignore", the terminaluses its regular transmit and receive speed. 

Modems that use a baud rate slower than 300 cannot use this feature (auto- 
matic speed selection). 

278 COMMUNICATION 



Disconnect Delay 

Values: 2 seconds (default), 60 ms, no disconnect 

When you enable modem control, the Disconnect Delay feature determines the 
time the VT300 takes to disconnect communication after losing the received 
line signal detect (RLSD). 

All countries except the United Kingdom should use the "2 seconds" setting. 
The 60 ms delay is for use in the United Kingdom. 

If you select "no disconnect" and the VT300 detects a loss of carrier, the ter- 
minal ignores RLSD (CD) after the beginning of the connection. 

If you try to disconnect and reconnect the line, the VT300 checks if RLSD is 
asserted before granting the connection. After it is connected, the terminal ig- 
nores the loss of carrier. In this case, the disconnect should be done when the 
DSR signal goes off. 

BREAK 

A break condition is the occurrence of a continuous space on a communication 
line for greater than one character time. A break consists of a 275 ± 25 ms 
space condition on the transmit data line during transmission. In local mode, 
the VT300 does not send the break character. The break (space) condition is 
separated from any later mark-to-space transition by at least 100 ms. 

Break Key 

The Break key has four functions. You can enable or disable the Break key in 
the Keyboard Set-Up screen. 

• Pressing Break sends a break function to the host. 

• Pressing Shift-Break causes a disconnect to occur. 

• Pressing Ctrl-Break sends the answerback message to the host. 

• When running dual sessions, the VT300 ignores any breaks it re- 
ceives. However, one or more error characters (backward question 
marks) may appear on the screen. 



COMMUNICATION 279 



STANDARDS AND CERTIFICATION 
Standards 

CCITT Recommendation V.25-bis (reference document CCITT AP VIII- 
43-E) with limitation to hardware handshaking. 

EIA STANDARD EIA-232-D Interface Between Data Terminal 
Equipment and Data Communications Equipment Employing Serial 
Binary Data Interchange. 

V.24 List of Definitions for Interchange Circuits between Data Terminal 
Equipment and Data Circuit-Terminating Equipment 1984. 

V.28 Electrical Characteristics for Unbalanced Double-Current 
Interchange Circuits 1984. 

The VT300 can connect to all modems conforming to the following standards: 
AT&T 103, 113, and 212A modems or plug compatibles including Digital's 
DF02, DF03, DF112, DF124, DF224 and DF242 modems. 

Certification 

United Kingdom (U.K.) attended operation only 

GPO, German ZZF V.21, V.22, V.22 bis, V.23, X.20 bis modems and 
data service units. 



280 COMMUNICATION 



COMPATIBILITY 
WITH OTHER DIGITAL TERMINALS 



C 















New 














Software 


Feature 


VT330 


VT340 VT220 VT240 VT241 Required 


Character Attributes 














Blink 


Y 


Y 


Y 


Y 


Y 


N 


Bold 


Y 


Y 


Y 


Y 


Y 


N 


Double high 


Y 


Y 


Y 


Y 


Y 


N 


Double wide 


Y 


Y 


Y 


Y 


Y 


N 


Invisible 


Y 


Y 


N 


N 


N 


Y 


Protection 


Y 


Y 


N 


N 


N 


Y 


Reverse 


Y 


Y 


Y 


Y 


Y 


N 


Transmission 


Y 


Y 


N 


N 


N 


Y 


Underline 


Y 


Y 


Y 


Y 


Y 


N 


Character Sets 














DEC Multinational 


Y 


Y 


Y 


Y 


Y 


N 


DEC Special Graphic 


Y 


Y 


Y 


Y 


Y 


N 


Down-line-loadable 


Y 


Y 


Y 


Y 


Y 


N 


ISO Latin-1 


Y 


Y 


N 


N 


N 


Y 


National replacement sets 


Y 


Y 


Y 


Y 


Y 


N 


Color 














Color palette 


N/A 


4096 


N/A 


N/A 


64 


Y 


Colors in display 


N/A 


16 


N/A 


N/A 


4 


Y 


Shades of gray 


4 


16 


N/A 


N/A 


4 


N 



281 



Feature 

Communication 

Baud rate up to 19.2 K 
Composite video output 
Optional integral modem 
Printer port 

Bidirectional 
Serial ports 



New- 
Software 
VT330 VT340 VT220 VT240 VT241 Required 



Y 


Y 


Y 


Y 


Y 


N 


N 


N 


Y 


Y 


Y 


N 


N 


N 


Y 


Y 


Y 


N 



N 



MMJ 


2 


2 











N 


RS232 


Y 


Y 


Y 


Y 


Y 


N 


20 milliamp 


N 


N 


Y 


Y 


Y 


N 


Compatibility 














VT52 


Y 


Y 


Y 


Y 


Y 


N 


VT100 


Y 


Y 


Y 


Y 


Y 


N 


VT125 


Y 


Y 


N 


N 


N 


N 


VT131 


Y 


Y 


N 


N 


N 


N 


VT220 


Y 


Y 


Y 


Y 


Y 


N 


VT240 


Y 


Y 


N 


Y 


Y 


N 


VT241 


N 


Y 


N 


N 


Y 


N 


Components 














Number 


2 


2 


2 


3 


3 


N 


Fan 


N 


N 


N 


Y 


Y 


N 


Firmware cartridge 


Y 


Y 


N 


N 


N 


N 


Display Features 














Character cell 














80 columns 


10x20 


10x20 


10x10 


10x10 


10x10 


N 


132 columns 


6x20 


6x20 


6x10 


6x10 


6x10 


N 


Display size (inches) 


14 


13 


12 


12 


13 


N 


Display type (flat or convex) 


F 


C 


C 


C 


C 


N 


Nonglare screen 


Etch 


Etch 


Coat. 


Coat. 


Coat. 


N 


Pixel aspect ratio 


Square 


Square Rect. 


Rect. 


Rect. 


N 


Rear panel cable cover 


Y 


Y 


N 


N 


N 


N 



282 COMPATIBILITY WITH OTHER DIGITAL TERMINALS 



Feature 

Display Features (cont) 

Resolution 

Vertical 

Horizontal 
Tilt-swivel base 

Dual Sessions 

2 cables 

1 cable (SSU) 

Graphics 

Cursors 

Rubber band box 

Rubber band line 

Cross hair 
Performance 

ReGIS 

Sixels 

Tektronix 4010/4014 

Local Editing 

ANSI X3.64 block mode 
VT131 block mode 

Off-Screen Memory 

132-column lines 
Characters 

Characters per session 
Multiple page formats 

25th Status Line 

Host 
Local 



New 

Software 
VT330 VT340 VT220 VT240 VT241 Required 



500 


500 


240 


240 


240 


N 


800 


800 


800 


800 


800 


N 


Y 


Y 


N 


N 


N 


N 


Y 


Y 


N 


N 


N 


N 


Y 


Y 


N 


N 


N 


Y 



Y 


Y 


N/A 


N 


N 


Y 


Y 


Y 


N/A 


N 


N 


Y 


Y 


Y 


N/A 


Y 


Y 


N 


Fast 


Fast 


N/A 


Slow 


Slow 


N 


Fast 


Fast 


N/A 


Slow 


Slow 


N 


Fast 


Fast 


N/A 


Slow 


Slow 


N 


Y 


Y 


N 


N 


N 


N 


Y 


Y 


N 


N 


N 


N 
Y 


144 


144 













19008 


19008 













9504 


9504 


N/A 


N/A 


N/A 




Y 


Y 


N/A 


N/A 


N/A 




Y 


Y 


N 


N 


N 


Y 


Y 


Y 


N 


N 


N 


N 



COMPATIBILITY WITH OTHER DIGITAL TERMINALS 283 



New 

Software 

Feature VT330 VT340 VT220 VT240 VT241 Required 

Set-Up Features 

Color map editor Y Y N N N N 

Full screen set-up mode Y Y N N N N 

User-defined key editor Y Y N N N N 

Other Features 

Host processing through Y Y Y Y Y N 

printer support 

Mouse/tablet support Y Y N N N Y 

local processing 

Terminal state inquiry Y Y N N N Y 



284 COMPATIBILITY WITH OTHER DIGITAL TERMINALS 



GLOSSARY 



Active position 

The location in page memory where the next typed character will appear. The 
cursor indicates the active position. 

Announcer 

A control function that prepares the terminal for the type of data used by a 
certain application. The VT300 supports three ANSI conformance levels that 
select the type of data used. These conformance levels are based on the ANSI 
standard Dp Ans X3. 134.1. 

ANSI 

American National Standards Institute 

ANSI character types 

There are two types of ANSI characters, graphic and control. 

Graphic characters are alphanumeric characters that you can display on the 
screen. These characters include letters, numbers, punctuation, and any other 
characters you can display. 

Control characters are characters you do not usually display. They make the 
terminal perform specific functions in data communication and text processing. 
Carriage return <CR), form feed (FF), and escape (ESC) are examples of control 
characters. 

ANSI partial page 

In local editing mode, all the characters on a page, from the beginning of a 
selected area to the cursor. 

285 



Application 

A computer program designed to perform a specific task, such as a word pro- 
cessing. Applications are usually coded using high-level programming lan- 
guages, such as FORTRAN or Pascal. 

Autorepeat 

A VT300 feature that makes most keys send their character repeatedly when 
you hold the key down. You can turn the autorepeat feature on and off by 
using the Keyboard Set-Up screen or the DECARM control function (Chapter 
11). 

Auxiliary keypad 

A group of keys on the right side of the VT300 keyboard that can send num- 
bers and punctuation marks, or special control functions defined by an applica- 
tion (Chapters 3 and 11). 

Baud rate 

The speed at which the terminal communicates with the host system or a 
printer. The baud rate is measured in bits per second. 

Bit 

Binary digit. The smallest unit of storable information in a digital machine. A 
bit can assume one of two values, (on) or 1 (off). 

Bitmap 

Random access memory used to store a bit-encoded representation of an image 
displayed on the monitor screen. The VT330 uses a 2-plane bitmap, where each 
pixel on the screen is represented by 2 bits. 

Block 

In edit mode, a section of edited data the terminal sends from the terminal's 
page memory to the host system. 

Block editing 

See local editing. 

Character cell 

The pixel area on the screen that the terminal uses to display a single graphic 
character. The VT300 uses a 10 x 20 pixel character cell for each graphic 
character. 

286 GLOSSARY 



Character encoding 

All terminals and computers encode information as binary digits, or bits. Older 
systems use 7 bits to encode each character. Newer systems such as the 
VT300 use 8 bits, which provide more codes. The newer systems can also use 
the 7-bit codes. 

The VT300 uses an 8-bit character encoding system and a 7-bit code extension 
technique. 

Character coding format 

There are two types of character coding formats, 7-bit and 8-bit. 

The 7-bit coding format uses 7 bits to store each character in the terminal's 
memory. The ASCII character set uses a 7-bit coding format. 

The 8-bit coding format uses 8 bits to store each character in the terminal's 
memory. The DEC Supplemental Graphic character set uses an 8-bit format. 

Character set 

There are two types of character sets, hard and soft. 

A hard character set is any one of the terminal's built-in character sets. Hard 
character sets in the VT300 include the ASCII, DEC Supplemental Graphic, 
ISO Latin-1 supplemental graphic, DEC Special Graphic, Nation Replacement 
Character (NRC), and DEC Technical. 

A soft character set is any character set that you define using a DECDLD 
device control string (Chapter 5). Soft character sets are also called down-line- 
loadable sets and dynamically redefinable sets. 

Code table 

A list of all characters in a character set with their codes. Most standard char- 
acter sets put similar characters into groups, so they have similar codes. A 
code table lets you see groups of characters and their relative codes clearly. 

Column 

A vertical row of character positions on the screen. You can display 80- or 132- 
column lines. 



GLOSSARY 287 



Compose sequence 

A series of keystrokes you can use to display a character that does not appear 
on any single key. Compose sequences start with the Compose Character key. 
See Installing and Using the VT330/VT340 Video Terminal for details. 

Context 

The operating information for a session. For example, the settings of set-up 
features are part of a session's context. The terminal maintains a separate con- 
text for each session. 

Control characters 

Characters that make the terminal or host system perform specific functions in 
data communications and text processing. The terminal usually does not dis- 
play control characters. The VT300 uses two groups of control characters CO 
and CI. 

CO (control zero) and C1 (control one) characters 

The VT300 uses the ANSI and ISO definitions for the functions of CO and CI 
controls. 

CO control characters are in postions 0/0 through 0/15 in the left half (GL) of 
the 8-bit code table. You can use CO characters directly in a 7- or 8-bit environ- 
ment. 

CI control characters are in positions 8/0 through 9/15 in the right half (GR) of 
the 8-bit code table. You can use Cl characters directly in an 8-bit environ- 
ment. CI controls can be used in a 7-bit environment as ESC Final escape 
sequences. 

Control functions 

Commands you use in your applications to make the terminal perform special 
functions. These functions range from the simple — editing data — to the com- 
plex — reporting on the terminal's state. Control functions include control 
characters, device control strings, control sequences, and escape sequences. 

Control sequence 

Any control function that begins with the Cl CSI control character. 

Coupled cursor 

A cursor that appears to pull the user window through the page. When the 
cursor tries to move beyond the borders of the user window, it pans in that 

288 GLOSSARY 



direction to keep the cursor visible. If the user window is the complete screen, 
the cursor looks like it is connected, or coupled, to the screen. 

Cursor 

A displayed box or underscore that indicates the active position in page mem- 
ory. The default cursor is a blinking box. You can select other cursor 
characters. 

DA 

Device attributes. A report the terminal can provide to the host on request. A 
DA report can provide the host with information about the terminal such as 
conformance level, basic features, identification code, and firmware version 
level. The host can use this information to adjust the computing environment 
and make the best use of the terminal's features. 

DA exchange 

An exchange between the host and VT300 in which the host requests and the 
terminal responds with basic information about the terminal, such as the termi- 
nal's identification code. 

Data flow control 

The method used to synchronize communication between the terminal and the 
host system. 

Data processing keys 

Keys that have three or four characters on the top of their keycap, rather than 
the normal two. Every keyboard except the North American keyboard has 
some data processing keys. 

DCS 

Introduces device control strings. DCS is a CI control character in position 9/0 
of the 8-bit code table. You can use the equivalent 7-bit escape sequence ESC P 
when coding for a 7-bit environment. 

DEC private control functions 

Private sequences created by Digital for specific families of products. ANSI se- 
quences and DEC private sequences follow ANSI standards for character codes. 

GLOSSARY 289 



In this manual, private control functions created by Digital have the prefix 
DEC in their mnemonic name. For example, horizontal cursor coupling mode 
has the mnemonic DECHCCM. All other control functions are ANSI 
sequences. 

DEC Multinational character set 

The factory default character set for the VT300. The left half of this set is the 
the 7-bit ASCII set (with CO control characters), stored in the GL table. The 
right half is the 8-bit DEC Supplemental Graphic set (with Cl control charac- 
ters), stored in the GR table. 

DEC Special Graphic character set 

This 7-bit character set has 94 graphic characters. Most of the graphic charac- 
ters are also in the ASCII character set. The other graphic characters include 
special symbols and line segments. Another name for this character set is the 
VT100 line drawing character set. 

DEC Supplemental Graphic character set 

This 8-bit character set has 94 graphic characters. The graphic characters in- 
clude letters with accents and diacritical marks, used in many European lan- 
guages. There are also special symbols, such as currency signs. 

DEC Technical character set 

This 7-bit character set has 94 graphic characters. The DEC Technical set has 
characters and symbols often used in technical applications, such as schematic 
and logic diagrams. 

Default 

A standard factory setting for a terminal feature. The VT300 uses default set- 
tings for features and control functions, until you change the settings. Many 
control functions use default values for parameters. If you omit a value, the 
terminal uses the default value. 

Designate 

Assign a character set to one of the terminal's four logical sets, GO through 
G4. This is the first of two steps in selecting a character set for use. The sec- 
ond step is mapping the character set. 



290 GLOSSARY 



Device control string (DCS) 

A special form of control function you can use for such operations as down-line- 
loading character sets or defining user-defined keys. Device control strings be- 
gin with the DCS control character. 

Diacritical marks 

Marks or symbols that indicate a change in the standard pronunciation of a 
letter. Examples of dicritics are acute accent ('), grave accent ('), and tilde 0- 

On the VT300, you use diacritical marks in two-stroke compose sequences. 

Display 

The area of the video screen where the terminal can present visible data. 

Display controls mode 

A special operating mode that lets you display control codes as graphic charac- 
ters, when you want to debug your applications. In this mode, the terminal 
does not perform control functions. 

Down-line-load 

Move data from the host system to the terminal. For example, you can down- 
line-load a soft character set into the terminal. 

Down-line-loadable (soft) character set 

A character set you can load into the VT300 from the host system. The charac- 
ter set can have 96 graphic characters. You can design your own soft character 
set. You can use the set in the GL or GR table. The terminal stores soft char- 
acters in its DRCS buffer. When you turn off the terminal, the soft characters 
are lost. 

DRCS 

Dynamically redefinable character set. See down-line-loadable character set. 

DSR 

Device status report. The host system sends a DSR request to ask the termi- 
nal for the operating status of six terminal features, such as VT300 operating 
status and cursor position. 

GLOSSARY 291 



DTR 

Data terminal ready signal. The state of this signal indicates the status of the 
printer port. 

Dual sessions 

A mode in which you can run two sessions at the same time. If you connect 
your VT300 to two systems, you can run a session on each system at the same 
time. 

Echo 

To display characters on the screen, in addition to sending them to the host. 
Either the host or the terminal can echo characters. 

Edit mode 

A mode of operation in which the terminal stores the information you type, 
rather than sending it immediately to the host system. You decide when to 
send your edited data to the host system. This mode requires host software 
support. 

Editing keypad 

The group of 10 keys {including the arrow keys) to the right of the main key- 
pad. Table 3-1 lists the codes sent by the editing keys, and Table 3-2 lists the 
codes sent by the arrow keys. Normally, you use the arrow keys to control the 
cursor on the screen. 

Eligible character fields 

Areas in page memory that the terminal can send to the host system in edit 
mode. Eligible characters are also called selected characters. 

Emulation 

A method that lets you use the VT300 like other Digital terminals. 

End-of-block character 

An optional character sent by the terminal at the end of a block transmission, 
in edit mode. 



292 GLOSSARY 



Environment 

The coding scheme a system uses to encode characters. Today, most systems 
use an 8-bit coding scheme, where each character of data is represented by an 
8-bit binary code. The VT300 can operate in a 7- or 8-bit environment. 

ESC 

The escape character. Introduces escape sequences. 

Escape sequences 

Control functions that begin with the CO ESC character. 

Firmware 

All commands and control functions that are built into the terminal, such as 
the editing functions. 

Font 

A set of graphic characters, all of one size and style. 

Full-cell fonts 

A font that can individually address all pixels in a cell. Usually, text fonts can- 
not individually address all pixels. 

Graphic left (GL) table 

The left half of the terminal's in-use table. The GL table can store up to 94 
graphic characters for immediate use. You can store characters in the 2/1 
through 7/14 range of character positions. You can use GL codes in 7-bit or 
8-bit environments. 

Graphic right (GR) table 

The right half of the terminal's in-use table. The GR table can store up to 96 
graphic characters for immediate use. You can store characters in the 10/1 
through 15/15 range of character positions. Some 8-bit character sets only use 
94 of these GR codes. You can use GR codes only in an 8-bit environment. 

Graphic characters 

Characters you can display on a video screen. Graphic characters include let- 
ters, numbers, punctuation, and any other characters you can display. 

GLOSSARY 293 



Graphic rendition 

The appearance of a display character, including all of its visual character attri- 
butes. You use the select graphic rendition (SGR) control function to select vi- 
sual character attributes. 

Graphics 

Pictures, graphs, and other images that can appear on the terminal's screen. 
Graphics are different from text, and the terminal uses a special mode of op- 
eration to display graphics. 

Hard character set 

One of six character sets built into the VT300, such as the ASCII and DEC 
Supplemental Graphic sets. 

Hard reset 

A control function that resets many of the terminal's features to a group of 
saved settings. You can perform a hard reset by selecting Recall Saved 
Settings in the Set-Up Directory. 

HLS 

The hue, lightness, and saturation color coordinate system. HLS is one of two 
universal systems for specifying colors. The other one is RGB. 

Home cursor position 

Usually the upper-left corner of the screen. However, home position can also be 
the upper-left corner of the scrolling region (that is, the area within the mar- 
gins). See "Origin Mode (DECOM)" in Chapter 6. 

Host 

The computer or terminal server that the terminal communicates with. 

Independent protection 

A style of character protection that lets you protect areas of page memory, 
independent of any visual character attributes. Compare with visual attribute 
protection. 



294 GLOSSARY 



In-use table 

The area in the terminal's memory that stores the character set(s) the terminal 
is currently using. The in-use table is comprised of the GL and GR logical 
tables. 

Interactive mode 

A mode in which the terminal immediately sends all typed data to the host 
system. This is the usual mode of operation for the VT300. You can also select 
edit mode. 

ISO 

International Standards Organization (ISO). 

ISO Latin Alphabet Nr 1 supplemental set 

This 8-bit character set has 96 graphic characters. The graphic characters are 
similar to those in the DEC Supplemental Graphic set. The ISO Latin-1 set 
includes letters with accents and diacritical marks, used in many European lan- 
guages. It also has other special symbols, not included in the DEC 
Supplemental Graphic set. The ISO Latin-1 set is specified in the ISO standard 
ISO 8859.1. 

Layers 

The different levels of data exchange between the VT300 and the host system. 
When you use SSU, there are three basic layers of data exchange between the 
terminal and host: ANSI/ReGIS/Tektronix/VT52, SSU, and XON/XOFF flow 
control. 

Line attribute 

The visual attributes for a complete display line on the screen. 

Local 

An operating state where data entered at the keyboard is sent to the screen, 
but not the host. The terminal stores data received from the host, until you put 
the terminal back on-line. 

Locking shift 

A control function used to map a designated character set into the terminal's 
in-use table as GL or GR. When you use a locking shift, the character set 
remains in GL or GR until you use another locking shift. 

GLOSSARY 295 



Map 

Move a designated character set into the terminal's in-use table as GL or GR. 
Mapping is the second of two steps in selecting a character set for use. The 
first step is designating the character set. After a set is mapped, it is available 
from the keyboard. 

Margins 

See scrolling margins. 

Mnemonic 

An abbreviated name for a control character or control function. For example, 
CR is the mnemonic for the carriage return control character. 

MSC 

See multiple system communications. 

Multiple system communications 

A method for managing sessions, using a separate communication line for each 
session. The other method for managing sessions is Digital's Session Support 
Utility (SSU). 

National replacement character sets (NRCs) 

A general name for a class of 7-bit, 94-character sets created for different lan- 
guages and dialects. The VT300 has 12 NRC sets for many European lan- 
guages. The NRC sets are based on ISO standard 646. 

NVR 

Nonvolatile RAM (random access memory). 

On-line 

An operating state of the terminal in which the terminal can communicate with 
a host system. The terminal sends data entered at the keyboard to the host. 
The terminal displays data received from the host on the screen. 

Operating modes 

Levels of conformance that the VT300 offers. 

The VT300 has two major operating modes, VT300 and VT100. You can select 
each mode from the keyboard via set-up, or from the host via control codes. 

296 GLOSSARY 



The VT300 uses standard ANSI functions in all operating modes, except VT52 
mode. See Chapter 1. 

Origin 

The home cursor position on the screen. You can set the home position at the 
upper-left of the screen or within the scrolling margins. 

Page 

A section of the terminal's page memory. Each page has left, right, top, and 
bottom scrolling margins. You can define the size and layout of a page by using 
set-up features or control functions. 

Page format 

The size and number of pages in the terminal's page memory. You can arrange 
page memory into 1, 2, 3, 4, or 6 pages, depending on whether you use single 
or dual sessions. You can also define the margins of a page. 

Page memory 

A storage area in the VT300 for displayable text. The size of this memory is 
equal to 144 display lines by 80 or 132 display columns. You can divide this 
memory into one or more pages. The amount of page memory available de- 
pends on whether you use single or dual sessions. 

Parameter characters 

Characters in a control function that define the action and/or limits of that 
function. 

Partial page marker 

An invisible marker that defines the position of the last character sent to the 
host on a VT1S1 partial page. The partial page marker applies only in edit 
mode. 

Pixel 

Picture element. The smallest unit of display on the video screen. All graphic 
characters are displayed with pixels. 

Port 

A connector on the rear of the terminal that lets the VT300 communicate with 
another device or host computer. 

GLOSSARY 297 



Presentation state report 

A VT300 report that indicates the settings of the terminal's character attri- 
butes and cursor, or the settings of its tab stops. 

Protected characters 

Positions in page memory that cannot be changed, erased, or moved with con- 
trol functions, under certain conditions. There are two styles of character pro- 
tection available, independent protection and visual attribute protection. 

Report 

Operating information that the terminal provides the host system. The VT300 
can provide the host with report information such as identification (type of ter- 
minal), cursor state, operating status, conformance level (1, 2, or 3), and 
extensions. 

Reset 

(1) To change the terminal's operating features to their default or saved set- 
tings. (2) To change the setting of an ANSI or DEC private mode to its reset 
state. 

Reset state 

One of two possible settings for an ANSI or DEC private mode. Modes are 
control functions that have only two settings. 

Restore 

To set the terminal to the latest saved operating state. Restoring the terminal 
is not the same as resetting the terminal. See reset. 

RIS 

Reset to initial state. 

RGB 

The red, green, and blue color coordinate system. RGB is one of two universal 
systems for specifying colors. The other one is HLS. 

ROM cartridge 

A read only memory cartridge that stores much of the terminal's firmware. The 
cartridge is installed at the rear of the terminal. The cartridge must be in- 
stalled for the terminal to operate. 



298 GLOSSARY 



Scrolling 

Moving data between the scrolling margins of a page. Data scrolled past the 
margins is lost from the terminal's page memory. 

Scrolling margins 

The top, bottom, left, and right boundaries on a page, beyond which data can- 
not be written or scrolled. 

Selected field 

A group of characters defined as eligible to be sent to the host in edit mode. 

Session 

An electronic connection between between the terminal and host. 

Session Support Utility 

Digital's software protocol for managing two VT300 sessions over one commu- 
nication line. The other method for managing sessions is multiple system com- 
munications (MSC). 

Set-up 

A series of display screens that list the terminal's operating features. Each 
screen lists a group of features, such as communications or printing. You can 
examine and change the current settings. For example, you can select the 
transmit or receive speeds, page size, and type of session management. 
Installing and Using the VT330/VT340 Video Terminal describes how to use 
set-up. 

Single shift 

A control character (SS2 or SS3) used to map a designated charge er set into 
the terminal's in-use table one character only. You use a single shift when you 
want to display the next character from a different character set. A single shift 
maps the G2 or G3 set into GL. The character set is active for only one char- 
acter, then the terminal returns to the previous character set in GL. 

Sixel 

A column of 6 pixels on the screen. When you load a soft character set into the 
terminal, you use sixel data to code each character. 

GLOSSARY 299 



Soft character sets 

See down-line-loadable (soft) character sets. 

Space compression 

A method of sending data in which the terminal omits unused character spaces 
in edit mode. 

ST 

String terminator character. ST is a Cl control character. You can use the 
equivalent 7-bit sequence ESC \ (1/11, 5/12) when coding for a 7-bit 
environment. 

Status line 

A line of text that appears on line 25 of the screen. There are three possible 
status line states: indicator (default), host-writable, and none. 

The indicator status line displays operating information about the terminal. 
This indicator status line appears in reverse video. The host-writable status line 
displays information provided by an application. When set to "none", the status 
line is black. 

Terminal state report 

A report that indicates the entire state of the terminal except for user-defined 
key definitions and the current soft character set. 

Top-row function keys 

The 20 keys (Fl through F20) on the top row of the keyboard. The first five 
keys — Hold Session, Local Print, Set-Up, Switch Session, and Break — are 
predefined function keys. You can define the function of the other 15 keys 
when they are shifted. See user-defined keys. 

Typewriter keys 

The keys on the main keypad. 

User-defined keys 

The 15 keys on the top row of the keyboard that you can define to send se- 
lected characters or control functions. You can program these keys with a 
DECUDK device control string, or you can define these keys from set-up. The 
15 keys are F6 through F14, Do, Help, F17 through F20. To use a user-defined 
key, you must press Shift-defined key. 

300 GLOSSARY 



UDKs 

User-defined keys. 

User-preferred supplemental set 

A standby set you use to provide general access to the supplemental set you 
use most. You can select this set to be ISO Latin-1 supplemental or DEC 
Supplemental Graphic. You can select the user-preferred set in set-up or with a 
DECAUPSS control function. 

Visual attribute protection 

A style of character protection for applications that require strict compatibility 
with the VT131 terminal. Visual attribute protection is only available in edit 
mode (DECEDM). Visual character protection applies to characters with the 
same visual character attribute. 

Visual character attribute 

A quality assigned to a graphic character that highlights the way the character 
appears on the screen, without changing the actual character. For example, the 
bold character attribute makes a character appear brighter on the screen. 

VT131 partial page 

In local editing mode, all characters on a page between the partial page marker 
and the cursor. 

7-bit code extension technique 

A method for expressing 8-bit control characters as 7-bit escape sequences. 



GLOSSARY 301 



Control Function Index 



This index lists all VT300 control functions. The index has three sections. You 
can find a function by 



• name 


page 303 


• mnemonic 


page 309 


• function 


page 314 


BY NAME 





— A— 

ANSI conformance levels — 80 

ANSI mode off (VT52 mode) DECANM 257 

Assign printer to active session — 185 

Assign user-preferred supplemental set DECAUPSS .... 80 

used to report the supplemental set 231 

Autoprint mode — 183 

Autorepeat mode DECARM 172 

Autowrapmode DECAWM 172 

— B— 

Backarrow key mode (delete key) DECBKM 170 



Control Function Index 303 



— c— 

Color table report DECCTR 207 

Column mode (Not recommended; see DECSCPP.) . . .DECCOLM 106 

Cursor backward CUB 162 

Cursor down CUD 163 

Cursor forward CUF 162 

Cursor information report DECCIR 210 

Cursor keys mode DECCKM 173 

Cursor position CUP 162 

Cursor position report CPR 202 

Cursor up CUU 162 

— D— 

Delete character DCH 121 

Delete line DL 120 

Designating character sets SCS 73 

Device attributes DA 196 

primary DA 197 

secondary DA 199 

Device status reports DSR 201 

cursor position report CPR 202 

extended cursor position report DECXCPR .... 202 

keyboard dialect — 203 

locator device port — 204 

printer port — 202 

user-defined keys — 203 

VT3 00 operating status — 201 

Double-width, double-height line DECDHL 116 

Double-width, single-height line DECDWL 116 

Down-line-loading soft characters DECDLD 90 

used to clear a soft set 101 

— E— 

Edit key execution mode DECEKEM .... 136 

Edit mode DECEDM 13 

Enable session — 256 

End protected area EPA 128 

End selected area ESA 143 

Erase character ECH 124 



304 Control Function Index 



Erase in display ED 122 

Erase in line EL 123 

Erasure mode ERM 119 

Extended cursor position report DECXCPR 202 



Guarded area transfer mode GATM 141 

NOTE: See Volume 2, Chapter 16 for the following graphics printing 
functions. 

Graphics expanded print mode DECGEPM . . Vol. 2 

Graphics print background mode DECGPBM. . . Vol. 2 

Graphics print color mode DECGPCM . . . Vol. 2 

Graphics print color syntax DECGPCS . . . Vol. 2 

Graphics rotated print mode DECGRPM . . .Vol.2 

Graphics to host — Vol. 2 

Graphics to printer — Vol. 2 

— H— 

Hard terminal reset RIS 244 

Horizontal and vertical position (See CUP. | HVP 162 

Horizontal cursor coupling mode DECHCCM .... 165 

— I— 

Insert character ICH 122 

Insert line IL 121 

Insert/replace mode IRM 119 

— K— 

Keyboard action mode KAM 170 

Keyboard usage mode DECKBUM 175 

Keypad application mode DECKPAM .... 173 

Keypad numeric mode DECKPNM 173 



Control Function Index 305 



_L— 

Line feed/new line mode LNM 171 

Line transmit mode DECLTM 138 

Locking shift GO LSO 78 

Locking shift Gl LSI 78 

Locking shift Gl, right LS1R 78 

Locking shift G2 LS2 78 

Locking shift G2, right LS2R 78 

Locking shift G3 LS3 78 

Locking shift G3, right LS3R 78 

— M— 

Mapping character sets — 76 

Media copy commands MC 182 

Multiple area transfer mode MATM 143 

— N— 

National replacement character set mode DECNRCM 70 

Next page NP 109 

Numeric keypad mode DECNKM 174 

— o— 

Origin mode DECOM 108 

— P— 

Page cursor coupling mode DECPCCM .... 166 

Page position absolute PPA 110 

Page position backward PPB 110 

Page position relative PPR m 

Pan down (scroll up) SU 163 

Pan left (scroll right) SR 164 

Pan right (scroll left) SL 164 

Pan up (scroll down) SD 163 

Preceding page PP 109 

Print all pages — 184 

Print composed main display — 184 

Print cursor line — 184 

Print form feed mode DECPFF 181 

306 Control Function Index 



Print page — !83 

Printer controller mode — 183 

Printer extent mode DECPEX 181 

Protected fields attribute DECPRO 129 

— R— 

Release printer — 185 

Report displayed extent DECRPDE 230 

Reportmode DECRPM 221 

Report selection or setting DECRPSS 227 

Request displayed extent DECRQDE 230 

Request mode DECRQM 218 

Request presentation report DECRQPSR . . . .210 

Request selection or setting DECRQSS 226 

Request terminal state report DECRQTSR .... 206 

Requesting the user-preferred supplemental set.. DECRQUPSS . . .231 

Reset mode (for ANSI and DEC private modes) RM 224 

Restore cursor DECRC 229 

Restore presentation state DECRSPS 216 

Restore terminal state DECRSTS 208 



Save cursor DECSC 229 

Screen mode DECSCNM 187 

Scrolling mode DECSCLM .... 187 

Select active status display DECSASD 189 

Select character protection attribute DECSCA 127 

Select graphic rendition (visual attributes).... SGR 115 

Select status line type DECSSDT 189 

Selected area transfer mode SATM 142 

Selecting an operating level DECSCL 67 

Selective erase in display DECSED 124 

Selective erase in line DECSEL 125 

Send/receive mode (local echo) SRM 186 

Sending 7-bit CI controls S7C1T 69 

Sending 8-bit CI controls S8C1T 69 

Set columns per page — recommended DECSCPP 106 

Set lines per page DECSLPP 107 

Set mode (for ANSI and DEC private modes) SM 223 

Set top and bottom margins DECSTBM 108 

Control Function Index 307 



Set transmit state STS 148 

Set transmit termination character DECTTC 144 

Single shift G2 SS2 79 

Single shift G3 SS3 79 

Single-width line DECSWL 116 

Soft terminal reset DECSTR 242 

Space compression mode DECSCFDM. . . . 147 

Start printer-to-host session — 184 

Start protected area SPA 128 

Start selected area SSA 143 

Stop printer-to-host session — 184 

— T— 

Tab clear TBC 245 

Tab stop report DECTABSR .... 216 

Terminal identification DECID 200 

Terminal state report DECTSR 207 

Text cursor enable mode DECTCEM .... 161 

Transmit execution mode DECTEM 148 

Transmit line termination characters DECTLTC 146 

Transmit mode DECXMIT 149 

Transmit rate limiting mode DECXRLM .... 273 

Transmit termination mode TTM 139 

— U— 

User-defined keys DECUDK 175 

— V— 

VTlOOmode — 66 

VT1 31 transmit mode DEC131TM 140 

VT300mode — 66 

Vertical cursor coupling mode DECVCCM 165 

Visual attribute protection (VT1 31 style) — See DECPRO. 



308 Control Function Index 



BY MNEMONIC 
—A— 



ANSI conformance levels 



80 



— c— 

CPR Cursor position report 202 

CUB Cursor backward 162 

CUD Cursor down 163 

CUF Cursor forward 162 

CUP Cursor position 162 

CUU Cursor up 162 



— D- 



DA. 



DCH 

DEC131TM . 
DECANM . , 
DECARM . 
DECAUPSS 

DECAWM . 
DECBKM . 
DECCIR. . 
DECCKM . 
DECCOLM 
DECCTR . 
DECDHL . 
DECDLD . 

DECDWL . 
DECEDM . 
DECEKEM 



Device attributes 196 

primary 197 

secondary 199 

Delete character 121 

VT1 31 transmit mode 140 

ANSI mode off (VT52 mode) 257 

Autorepeat mode 172 

Assign user-preferred supplemental set 80 

used to report the supplemental set 231 

Autowrap mode 172 

Backarrow key mode (delete key) 170 

Cursor information report 210 

Cursor keys mode 173 

Column mode (Not recommended; see DECSCPP.) 106 

Color table report 207 

Double-width, double-height line 116 

Down-line-loading soft characters 90 

used to clear a soft set 101 

Double-width, single-height line 116 

Edit mode I 36 

Edit key execution mode 136 



NOTE: See Volume 2, Chapter 16 for the following graphics printing functions. 

DECGEPM . . Graphics expanded print mode Vol. 2 

DECGPBM . . Graphics print background mode Vol. 2 

DECGPCM . . Graphics print color mode Vol.2 



Control Function Index 309 



DECOPCS. 
DECGRPM 



DECHCCM . 

DECID 

DECKBUM . . 
DECKPAM . . 
DECKPNM . . 
DECLTM . . . 
DECNKM . . . 
DECNRCM . . 
DECOM . . . . 
DECPCCM . . 
DECPEX . . . 
DECPFF. . . . 
DECPRO . . . 
DECRC . . . . 
DECRPDE . . 
DECRPM . . . 
DECRPSS. . . 
DECRQDE . . 
DECRQM . . . 
DECRQPSR. . 
DECRQSS. . . 
DECRQTSR. . 
DECRQUPSS . 
DECRSPS 
DECRSTS 
DECSASD. 
DECSC . 
DECSCA 
DECSCFDM 
DECSCL . . 
DECSCLM . 
DECSCNM . 
DECSCPP. . 
DECSED . . 
DECSEL . . 
DECSLPP. . 
DECSSDT. . 



Graphics print color syntax Vol.2 

Graphics rotated print mode Vol. 2 

Graphics to host Vol. 2 

Graphics to printer Vol. 2 

Horizontal cursor coupling mode 165 

Terminal identification 200 

Keyboard usage mode 175 

Keypad application mode 173 

Keypad numeric mode 173 

Line transmit mode 138 

Numeric keypad mode 174 

National replacement character set mode 70 

Origin mode 108 

Page cursor coupling mode 166 

Printer extent mode 181 

Print form feed mode 181 

Protected fields attribute 129 

Restore cursor 229 

Report displayed extent 230 

Report mode 221 

Report selection or setting 227 

Request displayed extent 230 

Request mode 218 

Request presentation report 210 

Request selection or setting 226 

Request terminal state report 206 

Requesting the user-preferred supplemental set 231 

Restore presentation state 216 

Restore terminal state 208 

Select active status display 189 

Save cursor 229 

Select character protection attribute 127 

Space compression mode 147 

Selecting an operating level 67 

Scrolling mode 187 

Screen mode 187 

Set columns per page — recommended 106 

Selective erase in display 124 

Selective erase in line 125 

Set lines per page 107 

Select status line type 189 



310 Control Function Index 



DECSTBM . . Set top and bottom margins 108 

DECSTR . . . Soft terminal reset 242 

DECSWL . . . Single-width line 116 

DECTABSR. . Tab stop report 216 

DECTCEM . . Text cursor enable mode 161 

DECTEM . . . Transmit execution mode 148 

DECTLTC. . . Transmit line termination characters 146 

DECTSR . . . Terminal state report 207 

DECTTC . . . Set transmit termination character 144 

DECUDK . . . User-defined keys 175 

DECVCCM . . Vertical cursor coupling mode 165 

DECXMIT. . . Transmit 149 

DECXCPR . . Extended cursor position report 202 

DECXRLM . . Transmit rate limiting mode 273 

DL Delete line 120 

DSR Device status reports 201 

cursor position report (CPR) 202 

extended cursor position report (DECXCPR) 202 

keyboard dialect 203 

locator device port 204 

printer port 202 

user-defined keys 203 

VT3 00 operating status 201 

— E— 

— Enable session 256 

ECH Erase character 124 

ED Erase in display 122 

EL Erase in line 123 

EPA End protected area 128 

ERM Erasure mode 119 

ESA End selected area 143 

-G- 

GATM Guarded area transfer mode 141 

— H— 

HVP Horizontal and vertical position (See CUP.) 162 



Control Function Index 311 



—I— 

ICH Insert character 122 

IL Insert line 121 

IRM Insert/replace mode 119 

— K— 

KAM Keyboard action mode 170 

— L— 

LNM Line feed/ new line mode 171 

LSO Locking shift GO 78 

LSI Locking shift Gl 78 

LS1R Locking shift Gl, right 78 

LS2 Locking shift G2 78 

LS2R Locking shift G2, right 78 

LS3 Locking shift G3 78 

LS3R Locking shift G3, right 78 

— M— 

MATM Multiple area transfer mode 143 

MC Media copy 182 

assign printer to active session 185 

autoprint mode 183 

print all pages 184 

print composed main display 184 

printer controller mode 183 

print cursor line 184 

print page 183 

release printer 185 

start printer-to-host session 184 

stop printer-to-host session 184 

Mapping character sets 76 

— N— 

NP Next page 109 



312 Control Function Index 



— p— 

PP Preceding page 109 

PPA Page position absolute 110 

PPB Page position backward 110 

PPR Page position relative Ill 

— R— 

RIS Hard terminal reset 244 

RM Reset mode (for ANSI and DEC private modes) 224 

— s— 

S7C1T Sending 7-bit CI controls 69 

S8C1T Sending 8-bit CI controls 69 

SATM Selected area transfer mode 142 

SCS Designating character sets 73 

SD Pan up (scroll down) 163 

SGR Select graphic rendition (visual attributes) 115 

SL Pan right (scroll left) 164 

SM Set mode (for ANSI and DEC private modes) 223 

SPA Start protected area 128 

SR Pan left (scroll right) 164 

SRM Send/receive mode (local echo) 186 

SS2 Single shift G2 79 

SS3 Single shift G3 79 

SSA Start selected area 143 

STS Set transmit state 148 

SU Pan down (scroll up) 163 

— T— 

TBC Tab clear 245 

TTM Transmit termination mode 139 



Visual attribute protection (VT131 style).. See DECPRO. 

VTlOOmode 66 

VT300mode 66 



Control Function Index 313 



BY FUNCTION 

ANSI Conformance Levels 

Announcing ANSI conformance levels 80 

Character Attributes 

See Visual Character and Line Attributes. 

Character Protection 

Independent 

End protected area (EPA) 128 

Select character protection attribute (DECSCA) 127 

Start protected area (SPA) 128 

Visual Attribute (VT131 Style) 

Protected fields attribute (DECPRO) 129 

Character Sets 

Assign user-preferred supplemental set (DECAUPSS) 80 

Clearing soft sets (DECDLD) 101 

Designating character sets (SCS sequences) 73 

Down-line-loading soft characters (DECDLD) 90 

Locking shifts 

locking shift GO (LSO) 78 

locking shift Gl (LSI) 78 

locking shift Gl, right (LS1R) 78 

locking shift G2 (LS2) 78 

locking shift G2, right (LS2R) 78 

locking shift G3 (LS3) 78 

locking shift G3, right (LS3R) 78 

Mapping character sets 76 

National replacement character set mode (DECNRCM) 70 

Single shifts 

single shift G2 (SS2) 79 

single shift G3 (SS3) 79 



314 Control Function Index 



Communication 

Transmit rate limiting mode (DECXRLM) 273 

Control Characters 

Sending 7-bit CI controls (S7C1T) 69 

Sending 8-bit CI controls (S8C1T) 69 

Cursor Movement and Panning 

Cursor backward (CUB) 162 

Cursor down (CUD) 163 

Cursor forward (CUF) 162 

Cursor position (CUP) 162 

Cursor up (CUU) 162 

Horizontal and vertical position (HVP) 162 

Horizontal cursor coupling mode (DECHCCM) 165 

Page cursor coupling mode (DECPCCM) 166 

Pan down (scroll up, SU) 163 

Pan left (scroll right, SR) 164 

Pan right (scroll left, SL) 164 

Pan up (scroll down, SD) 163 

Text cursor enable mode (DECTCEM) 161 

Vertical cursor coupling mode (DECVCCM) 165 

Display 

Insert/replace mode (IRM) 119 

Send/receive mode (SRM) I 86 

Screen mode (DECSCNM) 187 

Scrolling mode (DECSCLM) I8 7 

Select active status display (DECSASD) 189 

Select status line type (DECSSDT) 189 

Editing 

Delete character (DCH) 121 

Delete line (DL) 12° 

Erase character (ECH) 124 

Erase in display (ED) 122 

Erase in line (EL) I 23 

Erasure mode (ERM) H 9 

Control Function Index 315 



Insert character (ICH) 122 

Insert line (IL) 121 

Insert/replace mode (I RM) 119 

Selective erase in display (DECSED) 124 

Selective erase in line (DECSEL) 125 

Keyboard 

Autorepeat mode (DECARM) 172 

AutOwrap mode (DECAWM) 172 

Backarrow key mode (DECBKM) 170 

Cursor keys mode (DECCKM) 173 

Keyboard action mode (KAM) 1 70 

Keypad application mode (DECKP AM) 173 

Keypad numeric mode (DECKPNM) 173 

Keyboard usage mode (DECKBUM) 175 

Line feed/ new line mode (LNM) 171 

Numeric keypad mode (DECNKM) 174 

User-defined keys (DECUDK) 175 

Local Editing 

Edit key execution mode (DECEKEM) 136 

Edit mode (DECEDM) 136 

End selected area (ESA) 143 

Guarded area transfer mode (GATM) 141 

Line transmit mode (DECLTM) 138 

Multiple area transfer mode (MATM) 143 

Selected area transfer mode (SATM) 142 

Set transmit state (STS) 148 

Set transmit termination character (DECTTC) 144 

Space compression mode (DECSCFDM) 147 

Start selected area (SSA) 143 

Transmit execution mode (DECTEM) 148 

Transmit line termination characters (DECTLTC) 146 

Transmit (DECXMIT) 149 

Transmit termination mode (TTM) 139 

VT131 transmit mode (DEC131TM) 140 

Operating Level 

VT52 mode IDECANM, ANSI mode off) 257 

VT100 mode (DECSCL) 66 

VT300 mode (DECSCL) 66 

316 Control Function Index 



Page Memory 

Column mode <DECCOLM| — not recommended 106 

Next page <NP> 109 

Origin mode (DECOM) 108 

Page position absolute (PPA) HO 

Page position backward (PPB) 110 

Page position relative (PPR) 111 

Preceding page (PP) 109 

Set columns per page (DECSCPP) — recommended 106 

Set lines per page (DECSLPP) 107 

Set top and bottom margins (DECSTBM) 108 

Panning 

See Cursor Movement and Panning. 

Printing 

Media copy (MC) functions 

assign printer to active session 1°5 

autoprint mode 183 

print all pages I 84 

print composed main display I 84 

print cursor line 1° 4 

printer controller mode I 88 

print page i0 ° 

release printer l 8 ^ 

start printer-to-host session i84 

stop printer-to-host session I 84 

Printer extent mode (DECPEX) l g l 

Print form feed mode (DECPFF) 181 

NOTE: See Volume 2, Chapter 16 for the following graphics printing functions. 

graphics expanded print mode (DECGEPM) Vol. 2 

graphics print background mode (DECGPBM) Vol. 2 

graphics print color mode (DECGPCM) Vol.2 

graphics print color syntax (DECGPCS) Vol. 2 

graphics rotated print mode (DECGRPM) Vol. 2 

graphics to host Vol. 2 

graphics to printer Vol. 2 



Control Function Index 317 



Reports 

Control function settings 225 

report selection or setting (DECRPSS) 227 

request selection or setting (DECRQSS) 226 

Device attributes (DA) 196 

primary DA 197 

secondary DA 199 

Device status reports (DSR) 201 

cursor position report (CPR) 202 

extended cursor position report (DECXCPR) 202 

keyboard dialect 203 

locator device port 204 

printer port 202 

user-defined keys 203 

VT300 operating status 201 

Mode settings 218 

report mode (DECRPM) 221 

request mode (DECRQM) 218 

reset mode (RM) 224 

set mode (SM) 223 

Presentation state reports 209 

cursor information report (DECCIR) 210 

request presentation report (DECRQPSR) 210 

restore presentation state (DECRSPS) 216 

tab stop report (DECTABSR) 216 

Terminal identification (DECID) 200 

Terminal state reports 205 

color table report (DECCTR) 207 

request terminal state report (DECRQTSR) 206 

restore terminal state (DECRSTS) 208 

terminal state report (DECTSR) 207 

User-preferred supplemental set 231 

reporting the supplemental set (DECAUPSS) 231 

requesting the supplemental set (DECRQUPSS) 231 

Window reports 230 

report displayed extent (DECRPDE) 230 

request displayed extent (DECRQDE) 230 

Resetting the Terminal 

Hard terminal reset (RIS) 244 

Reset mode (RM) (for ANSI and DEC private modes) 224 

318 Control Function Index 



Set mode (SMI (for ANSI and DEC private modes) 223 

Soft terminal reset (DECSTR) 242 

Tabulation clear (TBC) 245 

Saving and Restoring the Cursor State 

Restore cursor (DECRC) 229 

Save cursor (DECSC) 229 

Session Management 

Enable session 256 

Visual Character and Line Attributes 

Double-width, double-height line (DECDHL) 116 

Double-width, single-height line (DECDWL) 116 

Select graphic rendition (SGR) 115 

Single-width line (DECSWL) 116 



Control Function Index 319 



Index 



7-bit ASCII code table, 16 to 18 
7-bit CI controls (S7C1T), 69 
7-bit code extension technique, 39 
7-bit codes, 15 

7-bit CO control characters, 28 to 30 
sending from the keyboard, 55, 57 
(Table 3-5) 
7-bit and 8-bit environments, 40 to 
41 
conventions for received codes. 40 
conventions for transmitted codes. 
41 
8-bit codes, 15 

8-bit CI controls (S8C1T), 69 
8-bit code table, 18 to 20 

CO (control zero) and CI (control 

one) characters, 18 
GL (graphic left) and GR (graphic 

right) characters, 20 
keyboard codes based on, 49 
used in 7-bit or 8-bit environment, 
40 
8-bit CI control characters, 31 to 32 
cannot send from keyboard, 55 



American National Standards 
Institute (ANSI), 4, 13 

ANSI mnemonics, 18 

ANSI sequences, 34 
ANSI conformance levels, 80 to 81 
ANSI modes 

setting and resetting, 223 to 225, 
220 (Table 12-2) 

requesting and reporting, 218 to 
223, 220 (Table 12-2) 
ANSI partial page, 137 
Arrow keys, 51 

codes, 52 (Table 3-2) 

selecting their function, 173 
ASCII code table, 16 to 18 

control characters, 18 

graphic characters, 16 
Autoprint mode. 183 
Autorepeating keys, 60 

turning on and off, 60, 172 
Autorepeat speed, 60 
Autowrapping text, 172 to 173 
Auxiliary keypad. See Numeric 
keypad 



-A- 



-B- 



Active position in page memory, 161 Backspace (BS) character, 50 



Index 321 



Baud rate, 9 

for autorepeating keys, 60 

for modems, 269, 271, 272, 278 

for non-Digital systems, 264 to 

265 
transmit rate limiting, 273 
Binary digits, 13 
Bitmap, 8 

Blinking characters, 115 
Block editing, 6. See also Local 

editing 
Bold characters, 115 

not available for control charac- 
ters, 116 
Built-in character sets, 9, 71 to 72 

(Table 5-1) 
Break key, 55, 61, 172, 175 , 
break function, 279 



CO and CI control characters, 18, 
20, 28 to 33 
converting CI codes to 7-bit code 

extensions, 41 
sending CI controls to the host, 

68 to 69 
using Cl controls in escape se- 
quences, 39 
Character attributes. See Visual char- 
acter attributes 
Character cell, 7 

for soft character sets, 82 to 83 
Character encoding, 12 to 44 
Character format, 260 
Character positions in a code table, 

16 
Character protection, 125 to 130 
independent style, 126 to 128 
reporting on the cursor position, 

212 to 213 
sequence summary, 134 (Table 8-4) 



visual attribute (VT131) style, 129 
to 130 
Characters and character sets, 15 
Character sets, 9, 20 to 28 

7-bit, 17 

8-bit, 19 

available. 73 (Table 5-1) 

DEC Multinational, 20, 21 to 22 

DEC Special Graphic, 26 

DEC Supplemental Graphic, 21 to 
22 

DEC Technical, 27 

display controls font, 42 to 43 

down-line-loadable (soft), 28, 82 to 
101 

ISO Latin Alphabet Nr 1 supple- 
mental graphic, 23 

letters with accents and diacritical 
marks, 21. 23 

local editing, 153 

national replacement character 
(NRC) sets, 24 to 25, 70 

report on active sets, 215. 231 

soft, 28, 81 to 101 

special symbols, 21, 23, 26 

VT100 line-drawing, 26 

VT200 and VT300 modes only, 23, 
27, 28 
Character sets, selecting, 72 to 101 

ANSI conformance levels, 80 to 81 

assigning the preferred supplemen- 
tal set, 80 

designating, 73 to 75 (Table 5-2) 

designating soft sets, 97 to 98 

mapping, 76 to 79 

national replacement character 
sets, 70, 79 

preferred supplemental character 
sets, 80 

soft character sets, 82 to 101 

VT100 mode, 76 (Figure 5-2) 



322 Index 



VT300 mode, 77 (Figure 5-3) 
Character size, 7 
Clr Field key, 58 
CLR PAGE key, 58 
Code table, 15 

7-bit ASCII code table, 16 to 18 
8-bit code table, 18 to 20 
Coding conventions, 40 to 41 
Coding standards, 13 to 14 
Color table report, 207 
Color printing. See Volume 2 of this 

manual 
Communication, 259 to 280 
break function, 279 
character format, 260 
connecting to Digital devices, 260 

to 263 
connecting to non-Digital devices, 

264 to 265 
data flow, 273 
features, 9 

modems, 271 to 272, 275 to 279 
ports, 265 to 270 
set-up screen. 274 
standards and certification, 280 
Communication features, 9 
Communication lines for sessions, 5, 

251, 252 
Compose Character key, 50 
Compose sequences, 48, 50. See also 
Installing and Using the VT300 
Series Video Terminal, Chapter 
6 
Connectors, 9, 265 
Control characters, 15, 18, 28 to 33 
control (CO) 7-bit characters, 28 

to 30 (Table 2-2) 
control 1 (CI) 8-bit characters, 31 

to 32 (Table 2-3) 
7-bit equivalents for 8-bit charac- 
ters, 32 to 33 (Table 2-4) 



in 7-bit or 8-bit environment, 40 to 

41 
in escape sequences, 39 
sending 7-bit or 8-bit Cl controls 
to the host, 70 
Control functions, 34 to 40. See also 
the Control Functionlndex 
7-bit code extension technique, 39 
control characters in, 39 
control sequences, 36 
device control strings, 37 
escape sequences. 35 
factory-default settings, 242 to 

243 (Table 13-1) 
sequence format, 35 
sent to the host, 47 
Control function settings, 225 to 229 
reporting, 227 to 229 
requesting. 226 to 227 
Converting binary code to an ASCII 

character, 87 to 88 
Coupled cursor, 164 
CR (carriage return) character 
Return key, 50 
in printing, 182 
CSI control character, 36 
Ctrl key. 50, 172 
Cursor, 161 to 163 
characters, 161 
home position, 108 
visible or invisible, 161 
moving on the current page, 161 

to 163 
sequence summary, 167 to 168 
Cursor control 

arrow keys, 51, 52 (Table 3-2) 
Cursor coupling modes, 164 to 167 
horizontal, 165 
vertical. 165 to 166 
page, 166 to 167 
Cursor information report, 210 to 



Index 323 



216 
Cursor movement 

on the current page, 161 to 163 

panning with the cursor, 164 to 
167 

sequence summary, 167 to 168 
Cursor position report, 202 

extended position report, 202 
Cursor state, 224 to 230 

restoring, 224 to 230 

saving, 229 

-D- 

Data flow, 273 

Data processing keys, 49 

selecting, 174 to 175 
Data terminal ready (DTR) signal, 

202, 203, 266, 267 
DCS control character, 37 
Debugging control codes in applica- 
tions, 41 
DEC Multinational character set, 20, 

21 to 22, 72 
DEC private mode settings, 218 to 
225 
reporting, 220 to 221 (Table 12-31, 

221 to 223 
requesting, 218 to 221 
setting and resetting, 223 to 225, 
220 to 221 (Table 12-3) 
DEC Special Graphic character set, 

26 
DEC Supplemental Graphic charac- 
ter set, 21 to 22 
assigning as the preferred supple- 
mental set, 81. See also DEC 
multinational character set 
DEC Technical character set, 27 
DEL (delete! character, 18, 50 
Delete Character key, 59 
Delete <x] key function, 170 to 171 



Delete Line key, 59 
Deleting 

a character, 121 to 122 

a line, 120 to 121 
Design and load a soft character set, 

82 to 98 
Designating character sets 

hard sets, 73 to 75 (Table 5-2) 

soft sets, 97 to 98 
Device attributes, 196 to 205 

alias responses, 199 

primary DA, 197 to 199 

secondary DA, 199 to 201 
Device control strings, 37 
Device status reports, 201 to 205 

cursor position, 202 

extended cursor position, 202 

keyboard dialect, 203 

locator device port, 204 

printer port, 202 

user-defined keys. 203 

VT300 operating status, 201 
Digital devices 

connecting to, 260 to 263 
Digital's private control functions, 
1-9. See also DEC private 
modes 
Display area, 7 
Displaying control characters on the 

screen, 16, 41 to 42 
Display controls mode, 41 

Control Representation feature in 
set-up, 41 

display controls font, 42 to 43 
Display features, 7 to 8 
Displaying pages from page memory. 

See Moving to another page 
Display Set-Up screen 

to select cursor character, 161 
Do key 

as a user-defined key, 175 



324 Index 



Double-width, double-height line. 116 
Double-width line, single-height line, 

116 
Down-line-loadable (soft) character 

set, 28, 82 to 101. See also Soft 
character sets 
device control strings, 37 
Dual sessions, 5, 249. See also Page 
memory and Session 
management 
session resources, 252 to 254 
independent resources, 252 to 253 
shared resources, 253 to 254 
two ways to manage sessions, 250 
to 252 
Dynamically redefinable character set 
(DRCS). See soft character sets 
DRCS buffer, 93 

-E- 

EDIT key, 59 
Editing 

deleting a character, 121 to 122 

deleting a line, 120 to 121 

erasing a character, 124 

erasing a line, 123, 125 

erasing protected characters. 119 

erasing the display, 122 to 123, 
124 to 125 

inserting a character, 122 

inserting a line, 121 

inserting or replacing data, 119 to 
120 

sequence summary, 131 to 133 
Editing key codes, 51 (Table 3-1) 
Editing keypad, 51 
Emulating VT series terminals, 65 to 
70 

level 1 (VT100 mode), 66 

level 3 (VT300 mode), 66 

reporting on the operating level, 



197 
selecting an operating level, 68 
Enter key 

sending the same character(s) as 
the Return key, 172 
Environments, 7-bit or 8-bit, 40 to 
41 
VT52 or VT100 mode (7-bit), 40 
VT300 mode (8-bit), 40 to 41 
Erasing 

a character, 124 
a line, 123, 125 
protected characters, 119 
the display, 122 to 123, 124 to 
125 
Erasure mode. See also Erasing 
effect on character protection, 126, 
127 
ESC character, 35 
Escape sequences, 35 
European languages. See National re- 
placement character sets 



FF (form feed) character, 171, 183 
in display controls mode, 44 

Function keys (Fl through F20), 50, 
55. See also User-Defined keys 
codes, 55 to 56 (Table 3-4) 
predefined keys, 55 

-G- 

G0 through G3 logical character 
sets, 72 
reporting on, 207, 213 to 216 
General features, 7 to 9 
Graphics left (GL) and graphics right 
(GR) logical tables, 20 
for display controls font, 41 to 42 
mapping designated sets to, 72 
reporting on, 207, 213 to 216 



Index 325 



GL characters in a 7-bit or 8-bit envi- 
ronment, 49 
GR characters in an 8-bit environ- 
ment, 49 
Graphic characters 

definition, 15 
Graphics tablet 

reporting on the locator device 
port, 204 

-H- 

Hard character sets, 71 to 72 (Table 

5-1) 
Hard terminal reset (RIS), 61, 244 

actions, 244 

caution against using, 244 

effect on user-defined keys. 176 
Help key 

as a user-defined-key, 175 
HLS (hue/lightness/saturation) color 
coordinate system 

reporting on, 206, 208 
Hold Session key. 55, 61. 172, 175 
Home Cursor key, 58 
Home cursor position, 108 
Host system 

and dual sessions, 5, 249 
Host-writable status line, 189 
HT (tab) character, 50 

-I- 

Independent character protection, 
126 to 128 
different from visual attribute 

(VT131 style) protection, 126 
to 127 
effect of erasure mode, 127 
Insert/Overstrike key, 58 
Inserting 

a character, 122 
a line, 121 



inserting or replacing data, 119 to 
120 
Inserting spaces. See Inserting 

characters 
International Organization for 
Standardization (ISO), 13 
ordering standards, 14 
In-use table, 20 
Invisible characters, 115 
ISO Latin alphabet number 1 supple- 
mental set, 23 
as part of ISO Latin-1 character 

set, 23 
selecting as the user-preferred sup- 
plemental set, 80 



-J- 



Jump scrolling, 188 



-K- 



Keyboard codes, 47 to 61 

7-bit control codes, 55, 57 (Table 
3-5) 

editing keypad, 51 to 52 

local editing mode, 58 to 59 (Table 
3-6) 

main keypad, 48 to 50 

standard keys, 48 to 49 

function keys, 50 

numeric keypad, 52, 53 to 54 
(Table 3-3) 

top-row function keys, 55, 55 to 
56 (Table 3-4) 

turning autorepeat on and off, 60 

unlocking the keyboard, 61 
Keyboard control functions, 170 to 
175 

locking and unlocking the key- 
board. 170 

selecting the <x] key function, 
170 to 171 



326 Index 



selecting the characters sent by 
the Return key, 171 

selecting the function of line feeds, 
form feeds and vertical tabs, 
171 

turning the autorepeat feature on 
or off, 172 

selecting the function of the arrow 
keys, 173 

numeric keypad, 173 to 174 

selecting typewriter or data pro- 
cessing keys, 174 to 175 

sequence summary, 191 to 194 
Keyboard dialect report, 203 
Keyboard Set-Up screen 

selecting typewriter or data pro- 
cessing keys, 49 

selecting numeric keypad codes, 
52 

selecting the autorepeat function 
for keys, 60 
Keys that do not repeat. 60 

-L- 

Light or dark screen, 187 

Line attributes, 8 
setting, 116 

Line feed/new line mode (LNM), 171 
to 172 
effect on Return key, 50, 171 

LF (line feed) character 

in display controls mode, 44 
and the Return key, 50, 171 
and printing, 183 

Local echo, 186 to 187 

Local editing, 6, 134 to 158 
7-bit environment, 154 to 155 
8-bit environment, 153 to 154 
character sets, 153 
control functions used, 135 
defining the size of the character 
block. 137 to 141 



description, 135 

end-of-block characters, 144 to 146 
end-of-line characters, 146 to 147 
examples, 149 to 153 
keys, 58 to 59 (Table 3-6) 
selected areas, 142 to 144 
selecting edit mode, 136 
selecting the characters to send, 

141 to 144 
selecting when to switch modes, 

136 to 137 
sending edited data to the host, 

148 to 149 
space compression, 147 
sequence summary, 156 to 158 
used with visual attribute charac- 
ter protection, 129 
Locator device port report, 204 
Lock key, 50, 172 

Locked keyboard. See also Unlocking 
the keyboard 
keys that still work, 61 
Locking shifts, 78 

-M- 

Main keypad codes, 48 to 50 

standard keys, 48 to 49 

function keys, 50 
Managing dual sessions, 5, 250 
Mapping a character set, 76 to 79 

locking shifts, 76, 78 

single shifts, 76, 79 
Modems, 271 to 272, 275 to 279 
Monitor size, 7 
Mouse 

reporting on, 204 to 205 
Moving to another page, 109 to 111 

summary, 113 

with cursor and panning functions, 
166 
Multiple-page display memory, 6 
Multiple system communications 



Index 327 



(MSC), 250 to 252 



-N- 



National keyboards 

differences. See Chapter 3 
National replacement character set 

mode, 70 
National replacement character sets 
(NRCs), 24 
characters that vary from the 

ASCII set, 25 
selecting, 70 
Negative image characters, 115 
Next Page key, 59 
Non-Digital devices 

connecting to, 264 to 265 
Nonvolatile RAM (NVR), 82, 241, 

244 
Numeric keypad 

codes, 52, 53 to 54 (Table 3-3) 
sending numeric characters or con- 
trol functions, 173 to 174 
Numeric parameters, 36 

-O- 

Operating levels 

character sets available, 72 (Table 
5-1) 

common features, 66 

control functions ignored, 67 
(Table 4-1) 

level 1 (VT100 mode), 66 

level 3 (VT300 mode), 66 

reporting on, 196, 197 

selecting, 68 
Operating modes 

on-line, 10 

local, 10 
Operating states 

reporting on, 205 

VT300 mode, 7-bit controls, 10 



VT300 mode, 8-bit controls, 10 
VT100 mode, 11 
VT52 mode, 11 
Operating status, 201 

-P- 

Page. 6 

compared to display, 161 

sending partial pages in local edit- 
ing, 137 
Page format, 106 to 109 

selecting 80 or 132 columns per 
page, 106 

sequence summary, 112 to 113 

setting lines per page, 107 

setting the page origin, 108 

setting top and bottom margins, 
108 
Page memory, 6, 102 to 113 

description, 103 

for a single session, 104 

for dual sessions, 105 

margins. 103 

moving to another page, 109 to 
111 

sequence summary, 112 to 113 
Page sizes 

default, 103 

single session, 104 

dual sessions, 105 
Panning. 163 to 167 

direction. 163 to 164 

with the cursor, 164 to 167 

sequence summary, 167 to 168 
Parameters 

numeric, 36 

selective, 37 
PF1 through PF4 keys, 174 
Pixels, 82 
Ports, 265 to 270 
Power-up 



328 Index 



clearing user-defined keys, 176 
Predefined function keys, 55 
Presentation state reports, 209 to 
218 
cursor information report, 210 to 

216 
requesting, 210 
restoring, 217 to 218 
tab stop report, 216 
Prev Page key, 59 
Primary DA report. 197 
Printer port control functions, 181 to 
182 
selecting how much data to print, 

181 
sending a form feed, 181 to 182 
Printer port report, 202 
Printing control functions, 182 to 
185 
assigning the printer to the active 

host session, 185 
printing a display line: autoprint 

mode, 183 
printing all pages, 184 
printing a page, 183 
printing the cursor line, 184 
printing the screen, 184 
releasing the printer, 185 
sending characters directly to the 
printer: printer controller 
mode, 183 
starting and stopping the printer- 
to-host session. 184 
sequence summary, 191 to 194 
Printing visual attributes, 185 to 186 
sending line attributes. 185 
sending visual character attributes, 
186 
Private sequences, 34 
Protected and unprotected areas, 127 
to 128 



Reports, 195 to 240 

ANSI and DEC private mode set- 
tings, 218 to 225 
control function settings, 225 to 

229 
cursor state, 229 to 230 
device attributes, 196 to 200 
device status reports, 201 to 205 
presentation state, 209 to 217 
sequence summary, 233 to 240 
terminal identification, 200 
terminal state reports, 205 to 209 
user-preferred supplemental set, 

231 to 232 
windows, 230 to 231 

Releasing the printer, 185 

Resetting the terminal, 241 to 248 
hard terminal reset, 244 to 245 
sequence summary, 246 
soft terminal reset, 242 to 243 
tab clear, 245 

Return key, 50, 171 

Reverse characters. See Negative- 
image characters 

ROM cartridge firmware, 7 



Screen display control functions, 186 
to 190 

local echo, 186 to 187 

light or dark screen, 187 

scrolling mode, 187 to 188 

selecting the indicator or host sta- 
tus line. 188 to 190 

sequence summary, 194 
Scrolling 

speed, 187 to 188 

versus panning, 160 
Scrolling region (local editing), 138 
Secondary DA report, 199 to 200 



Index 329 



Select character set (SCS) sequences, 

73 to 75 (Table 5-2) 
Select graphic rendition (SGR). See 
Visual character and line 
attributes 
Selected areas in local editing, 142 

to 144 
Selecting a character set, 72 to 81 
in VT100 mode. 76 
in VT330 mode. 77 
Selecting a page size. See Page 

format 
Selecting a status line, 188 to 190 
Selective parameters, 37 
Session management, 249 to 256 
dual sessions, 249 to 250 
multiple system communications 

(MSC), 254 
session resources, 252 to 254 
SSU, 254 to 255 
Session Support Utility, 254 to 255 
SSU environment, 254 to 255 
using SSU, 255 
Session Switch key, 55. 172, 175 
Setting line attributes. 116 to 117 
single-width, single-height line. 

116 
double-width, single-height line. 

116 
double-width, double-height line, 
116 to 117 
Setting visual character attributes. 

114 to 117 
Set-up, 7 

Set-Up key, 55, 175 
Shift key, 50, 172 

for user-defined keys, 175 
Single shifts, 79 

Single-width, single-height line. 116 
Sixels, 84 

Soft character sets. 28, 71, 82 to 
101 



clearing, 101 
coding, 84 to 89 
converting binary code to an 
ASCII character, 87 to 88 
(Table 5-5) 
designating, 97 to 98 
designing, 82 to 83 
down-line-loading, 90 to 96 
example, 98 to 100 
SP (space) character, 18, 182 
Status line, 187 to 190 
Supplemental character sets, See 
Character sets 

-T- 

Tab key. 50 
Tab stops 

converted to spaces when printing 

current page, 182 
reporting on, 216 
Terminal identification, 200 
Terminal state reports, 205 to 209 
reporting the color table, 207 to 

208 
reporting the terminal state, 207 
requesting, 206 
restoring, 208 to 209 
Text features, 8 
Top-row function key codes, 55 to 56 

(Table 3-4) 
Transmit key, 59 

Transmit Rate Limiting set-up fea- 
ture, 60 
Typewriter or data processing keys, 
49, 174 to 175 

-U- 

Underlined characters, 115 
Unlocking the keyboard, 61, 170 
User-defined keys (UDKs), 175 to 
181 



330 Index 



locking and unlocking, 178 

notes on loading UDKs, 179 to 
180 

programming UDKs. 176 to 181 

summary, 192 

UDK memory space, 176 

using UDKs, 176 
User-defined keys report, 203 
User-preferred character sets. See 

Character sets 
User-preferred supplemental set re- 
ports, 231 to 232 

reporting, 232 

requesting, 231 
User windows, 5 



Visual attribute protection, 129 to 

130 
Visual character and line attributes, 
114 to 117 

reporting on the writing rendition, 
211 to 212 

setting visual character attributes, 
114 to 117 

setting line attributes, 116 to 117 

sequence summary, 117 
VT (vertical tab) character, 171, 182 

in display controls mode, 44 
VT52 mode, 257 to 258 

7-bit environment only. 40 

control codes, 258 

entering, 257 

exiting, 258 
VT100 line-drawing character set, 26 
VT100 mode, 11 

7-bit environment only, 40 



limits. 66 to 67 
selecting, 68 

selecting character sets, 76 
VT131-style block editing. See Local 

editing 
VT131-style character protection. See 

Visual attribute protection 
VT131 partial page, 137 
VT200 series terminals 

using VT200 settings. See VT300 
mode 
VT300 features, 3 to 11 
VT300 mode, 10 
no limits. 66 
selecting, 68 

selecting character sets, 77 
VT300 series terminals, 3 to 4 
compared to other VT series ter- 
minals, 281 to 284 

-W- 

Wait indicator. 61, 170 
Windows 

cursor movement and panning, 

163 to 167 
reporting, 230 
requesting, 230 
user windows, 5 
Wrapping text automatically, 172 to 
173 

■X- 

<x] (delete) key, 50 

as a backspace key, 170 to 171 
XON/XOFF signals. See 
Communication 

in display controls mode, 44 



Index 331 



Digital Equipment Corporation • Maynard, MA 01 754