Worked on a modular PCB for a Ninja Tap with FM-Towns controller compatibility. The name of such interface could not be other than..

Ninja-Towns

Schematic

A preview of the PCB (couldn't resist to google for "ninja town" and found something to "inspire" the logo and the ninja character.

Two boards should be stacked and the jumpers should be done on the upper board which is custom made for an off the shelf PB-203 box.