So a while back I acquired a copy of the interesting-looking "Game Basic for Sega Saturn". It came with a pair of manuals (all in Japanese), game CDs, a cable to allow you to connect the Saturn's "Communication Connector" to a PC's parallel port, and the really interesting bit: a keyboard with a Saturn connector on the end.
I couldn't find anything through some casual googling, and I was curious to know if anyone knew how to code for this thing. (Since the Saturn connector is electrically compatible with the Megadrive, a quick adaptor could make it into a keyboard for the Megadrive.)