The Onyx box redated all the 68K and later Intel or other systems.   John Bass brought one to USENIX to demo in early 1980 ru a V7 port and everyone was blown away. Playing with it. It was a desktop (19" rack) system that worked like a PDP-11.   I don't remember the bus, but I would guess it was either custom or Multibus-I.

Besides being one of the first non-PDP-11 'ports', the original lockf(2) system call was defined for the database that they had built.  John would release the specs to /usr/group later.  I remember at one meeting in the early 1980s discussing if file locking needed to be in the original specification (Heinz probably remembers also as the chair of that meeting).  I'm not at home, so I don't have the document to see if it was picked up.  The argument was that serious computers like VMS or the like ran real databases and without file locking UNIX would never be considered a real OS that people could use.

BTW: Joy would later use Bass's call as a model for the 4.2 call, but Joy made the locks advisory, Bass's version was full / mandatory locks.

FWIW: I think a search will pick up a number of other Z8000 based systems, but Onyx was the first UNIX box.