Apollos tend to be really thin on the ground (manuals and Domain OS media even more so). -- I'd still like to scan the material that Bob Shannon has, since, as you've noticed, DOMAIN docs were tossed when the machines were. Apollo hardware docs are unobtainium. I tried contacting the one person who was working on porting NetBSD to DN3xxx/4xxx, because he had done a LOT of reverse engr and boot prom disassembly for the machines, but got nowhere. It sounded like he lost interest in the whole thing, and didn't bother to save what he had done.