Specifically, you'd connect to a cluster of VMS machines (some VAXes, some Alphas) which had a text interface to the (reputedly) off-campus mainframe which did registration. I recall that "vaxa" was usually the most crowded because it was always listed first, but if you got on one of the Alpha systems it was more responsive.
Everyone insisted that you MUST use telnet, not ssh (although ssh was enabled) because having hundreds of students logged onto each VAX was enough load already without introducing cryptography. If I remember right, you could get a list of who was logged in which indicated if they came in via telnet or SSH, and people did get shamed for using SSH.