1989-90 you could still dial in to "Nyx", a PDP-11 at University of Denver, running 2.? BSD. The big attraction was Usenet access, Nyx probably got it via uucp.
Personally I was put on SVR3/3B2, and SunOS on IPX/SLC type systems, along with an awareness of all kinds of other stuff available there, such as a "recreational" 4.3BSD VAX.