I wonder, since the hardware is based off the PS1 and there are various variants of this System board, would it be possible for this multi to support System 10 and 11 as well?
Granted, the system 12 library is awesome enough as it is...
I've not done anything on system 12 other than a few repairs.
I'm sure darksoft and apocalypse will defeat the keycus on these easily enough - it's just a "MACH" PLD with KC number.
The chips are locked but with equipment they can be bruteforced.
After dumping a few different ones it should be easy enough to get an idea of what they do.. (at the moment the function is unknown other than address mapping for the romboard part)
After the SYS 11, the keycus changed to this mach type...... SYS 11 and earlier they are all similar and use "spin off's" of the old school keycus(s).