> Out of curiosity, has anyone been putting effort into decrypting the x-in-1 boards?
> I'm less interested in this from the standpoint of seeing them emulated (which, IMHO,
> is pretty much a 'who cares' sort of thing), but am interested in seeing what the
> underlying code for both the UI and emulator may be.
39-in-1 runs (slowly). When it's booting up and listing each game, it's actually emulating it until the POST is complete, inserting a coin, and then save-stating it to RAM. This is why each game takes a wildly different amount of time for its name to be printed during that startup.
Then when you pick a game to run it just resumes that save state. It's possible in the MAME debugger to skip that step; it starts up immediately but when you pick a game it then just POSTs and goes through attract mode
I strongly believe the emulator is MAME although I haven't tried to decompile it or anything, and they did a good job scrubbing it for tell-tale strings (as opposed to Konami's PS2 classics series, which has Aaron's name in it and the MAME version string). The game selection and the timeframe pretty much guarantees that.