Wanted: Altair / S-100 serial comms board w/ documentation

Just taking a stab.. I've run out of options trying to locate docs for the lone S-100 serial board in my stash, so I think it's time to look for a new unit. I don't own a logic analyzer, nor have I sufficient experience to figure out how to put my current board to use in the absence of docs.. so it goes. Does anyone have an S-100 (for Altair, in specific) RS-232 / serial communications board with available documentation? Just looking for something that can be made to work with a common serial terminal (emulated) so I can play around with BASIC and so forth. Plan is to use a basic 486 / Pentium laptop running Linux + Minicom or similar to emulate a VT-whatever on the Altair's comms port. (As an aside.. a bit of a mea culpa - I +did+ once own a genuine ITT (I think it was ITT) tele-tank with a paper tape machine. Picked it up for $15 at a local electronics surplus - AxMan - back in the early 1980s. It didn't work right.. or at least I had no idea what to do with it. When powered-up, it would begin to print blank lines over & over, line after line.. just sat there, running away like crazy doing nothing. I had not the slightest idea how to deal with it, so I removed the works WINDOW. It was so heavy, I didn't want to have to carry it back down. The base served as an excellent printer stand for several years, and the not-so-obvious access panel did well to conceal various contraband during the same period.)