After many failed tests of OSes, finally found one that passes the OS check for games that want C1.1 .................
That is OS 1221.
However, the game does not seem to fully load, or the diagnostic button has been moved to a different location!?
Just like a normal RAM clear and first load, the screen says Call Attendant, Time Date not Set, Denom not set, etc. Ok, let's set it! .. Push diagnostic button and nothing.
Hold configuration button. Nothing. Close door, "Performing Memory Check" or whatever it says. Jackpot reset switch works but you can't configure from there. Exit,
Open Door, hit diagnostic button.. Nothing.
Leave it sitting there for 7 hours, Open door, hit diagnostic button, nothing. lol WTF
RAMClear, load a game that uses that OS (for sure).. It does pretty much the same thing but before it gets to the Time/Date not set, it keeps showing Call Attendant and continues to load a bunch of files to RAM (?? BB1 has no HD)... THEN it says Time/Date not set.
So, I dunno, maybe OS 1221 doesn't do an OS Validation check? Doesn't seem likely since every other OS does.
Not sure if 1221 is really C1.11 or if I am hitting a wall. If not, where could the diag button be moved to? Could it be J10 Pin(s) 15 and/or 16? I dunno what those are for.