As fhub said above, there's a preliminary MAME driver for Saitek Prisma. The H8 internal ROM was dumped electronically by Sean Riddle, with a similar method as Hitachi HD6301Y0.

It was actually dumped from a CC 2150L, but I'm pretty sure it's the same MCU and if someone makes a photo of a Prisma MCU later we'll know for sure.

Yesterday he also dumped the H8 internal ROM from a Mega 2050X, which has the same MCU as GK 2000. So, yeah, that's a Frans Morsch chess program.