My memories from the early 1980s are of a room full of undergrads
working on rows of VT100s (maybe 50+ at least?) on a DECSYSTEM-2065
running TOPS-20.
Things usually seemed to run pretty well on that system, until the
night before programming assignments were due.
Nothing quite like a room full of VT100s beeping in unison and
printing the dreaded "%DECSYSTEM-20 not running" message when things
hit the maximum load, followed by waiting for the system to restart
and hoping your work in progress was saved recently.