Please help identify S-100 boards

Hello all, I just obtained three S-100 boards that I thought were floppy controllers, but on inspection, may be something altogether different. I have no documentation on these boards, so here's the description: All three are marked "DYSAN (c) 1982" Two are marked "Wear Tester Cert. Bd." One is marked "Model V TrackWriter Certifier Sub." All three have 34-pin and 50-pin connectors, and all three look to be the same PCB layout, but with different components present or absent, and slightly different silkscreenings. For example, the two "Wear Tester" boards have ByteDAC chips in two sockets, but the "Model V" has those sockets empty. Most of the other chips on the boards are either standard "74" logic, or Op-Amps, or the aforementioned ByteDAC chips. All three also have a National LH0032CG in a can (don't know if that's significant or not). If anyone can identify these boards, or more importantly provide documentation (including schematics), I would surely appreciate it! I am willing to trade $$$ for information... Thanks! Rich B. P.S. I'm a digest subscriber, so I will not reply immediately if you send to the list....