I forgot mention that I'm working on the reverse too. Getting Altair Basic to work on other machines too. Once the code is patched to work with other SIO cards. Since this is more popular.
The trick is get to get it to bootup using EPROM's -- which isn't that hard-- with a little copy routine to move it down to Ram (since it was coded to run out of Ram -variables are embedded inthe code--and not Rom as others are).
The hard part is I haven't found the source code in a file. I left off where I OCR'd the source code from the manual. But the pdf wasn't scanned very well, so there were alot of typos to fix. Then my hard drive crashed, so I had to start all over.
So I was going to ask Bill is he could scan it in again with his manuals--I hope he has a print copy-- then the OCR should zip right thru it with far less typos.
That Imsai Basic runs out of Rom. Once it's patched with the SIO init code, another copy can be burned in Eproms. There's several Ram cards which let you use Eproms too. I suggest getting one that supports at least 6116 Ram (2716 Eproms)--less Roms to deal with, only 4 roms. The others that support only 2708 Roms is ok too, that would be 8 Roms then. Please don't ask for 1702's unless you like getting tortured :) That's fine you just like little programs.
But I don't have a 2708 burner--another project that's waiting. Bill has a 2708 programmer card that needs to get tested still. But these days I like to program this stuff on my PC and not use my machines any more for this.