Expansion terminals on the underside of a Twin Fami - what are they for?

[Frank_fjs]

As per forum title, does anyone know what the expansion terminals on the underside of a Twin Fami are for?



The Japanese text says 'Expansion Terminal D and C' but that's all I know.

[petik1]

I'd love to know. I think senseiman said that if you unplug it, it doesn't affect the twin fami at all, cartridge port or fds.