I've been meaning to run up MP/M in an emulator for a while now, and have a play. A multi-user, multi-tasking, multi-threading[1], and multi-terminal real time

I've been meaning to run up MP/M in an emulator for a while now, and have a play. A multi-user, multi-tasking, multi-threading[1], and multi-terminal real time OS, with a limited form of job control. Not bad for 1979/1980 on an 8080 or Z80. [1] when non bank-switched, or with constraints when bank switched.