Interact's 'Arcade pro' genesis/snes controller has detachable cables adapting from a 15 pin out plug. I don't suppose that happens to be neo geo pinout, without rearranging pins, is it?
it's the wide 15 pin, though. However I do now notice that there's a separate PC (gameport) version of the controller, so that'd be my current pinout guess. I was just hoping I could be sneaky and chuck a simple neo geo extension on it without rearranging the pinout.