You didn't have a router with dialup, or early DSL, where the modem was a separate device. You'd often get publicly routable IPv4s in your university dorm, too. See also napster. :-)
Just amazing. I had a need for something like this but wound up building it out in Mathesar. That, too, is an amazing project, but my business logic has to remain separate. Jeepers, you're even getting into labor accounting - well done!
Of course, the surest way to experiment with an alternative sleep schedule is to simply take care of a newborn, something humans have gotten pretty good at over the millennia.
Diku and most (all?) other MUDs were "BSD" socket-based. Windows did not even ship with a sockets layer (winsock) until 1994, with Windows NT 3.5, and it made its way to consumers with Windows 95.
Merc did allow for compiling on Mac and MS-DOS, but in this mode reads and writes to the console, without a socket implementation. No multiplayer.