IIRC, Morrow Designs biggest, baddest S-100 machine (used a switching PS!) could run CP/M but with a special boot ROM (on the backplane with serial I/O I believe) also ran UNIX System V substituting a 68000 CPU board for the usual Z80. That was the Tricep I believe, which came out around 1984. Bob Stek Saver of Lost Sols