It's easy to convert a TurboTap to use Turbografx-16 controllers on a PC Engine. I used Monoprice's
$1.90 MDIN8 6ft extension cable. You could also drill a hole in the TurboTap and have both a TG16 and PCE plug attached at the same time. The PCE Multitap can be converted to a TG16 using this same method with a large DIN-8 cable.
Simply unplug the original TG16 cable connector. Then solder the mini DIN-8 cable to the bottom of the PCB below the controller connector, matching the original wire colors (except grey is now black). From the top, the colors will be:
Red
Orange
Yellow
Green
Purple
Blue
Black
Brown
Bare ground shield
There is a single 10uF 50v capacitor (obscured here by the grey cable) that can be replaced while you're in there.Both TG16 and PCE cables attached. I did this while traveling and had brought along a pencil iron instead of my Hakko 928 station, so the soldering doesn't look so pretty. I tested the TurboTap on a Turbo Duo.