PCE and Coregrafx both have very little free space inside but TG-16 has ridiculous amount of free space inside. I believe Duo has enough room as well. Would it be worthwhile to hack in a multi-tap inside a TG-16 to have 5 built in ports, and a switch to toggle between single controller mode and multi-controller mode? Looking at the controller schematic, it seems only 2 lines would need to be toggled. I can't find a schematic for multi-tap but I am guessing if when it's in 1 controller mode, forcing enable on the multi-tap chip to high would disabled, which would stop it from interfering. Plausible, yes but practical? Or would all single-player game happily ignore the multi-tap's player 2-5 ports and work with a controller on port 1? In that case, the hardest part of the hack would be plastic shell.
I use a multi tap on my core grafx as a controller extension, haven't come across a game that plays up with it (I only have one controller)
