There was a burst of hacking because of the final transition to UNIX. I was privileged to experience the much more diverse before time: A DECSYSTEM-20 was the main campus computer (it used a Z-80/S100 bus custom terminal multiplexer), the OS course involved writing an OS in PDP-11/23 assembly language, you could write your documents using the Wang word processing computer, of course there were VAXen and there was even an IBM mainframe. There were some UNIX machines (3B2s..), but everything changed when the DEC-20 was replaced with an Encore Multimax and Decstation-2100s (I remember "xtank" was a popular multiplayer game on them).

I could see the vestiges of the previous burst of hacking in the DEC-20's student written software library.

The popularity of the messaging programs should have been a big hint to us..