This is a printable A/V cable adapter housing for the TurboGrafx-16. Typically, the TG16 only outputs (low quality) RF, unless you buy the expensive and hard to find Turbo Booster. But the signals you need are available on the expansion connector on the back. Here's a page describing the process of making a DIY cable: http://www.cgquarterly.com/articles/tg16_cable.htm , and the full pinout information is here: http://www.gamesx.com/misctech/pcebp.php . I made one of those cables a couple years ago, but my biggest complaint was that the wires would pop out if you moved the console... which happens quite often, since the controller cord is so short.
So I designed this housing, which is compatible with 0.1" Molex crimp pins (C-Grid III). I purposefully made it short (about the same length as the pin), and used a very thin A/V cable, so I could install the rear console cover and route the cable out the side (without having to modify anything). The cable I used was an A/V cable from a Samsung Galaxy S i9000, which was $5 shipped on ebay. This fits snug, but still pops in and out without much trouble (just a little bit of wiggling to get it out).
Attached is the STL file as I printed it, as well as the Sketchup file for that same model, and an earlier one I did with smaller holes for all pins. With the earlier model, it was very tight and difficult to remove, so I widened the holes and removed a large number of the pins. But if your printer is better than mine, or if you want access to other signals, that older model may work better for you. The video pins were the only ones I made compatible with the crimp pins... the rest are just dummy holes (I was afraid it may be too weak with very thin walls between all the pins).