Figured this out. Model number doesn't bring up anything, but it is easy to find the manual if you search for "BayStack 450-24T Switch".
Default comm settings are 9600 8N1 with software flow control (Xon/Xoff) ENABLED. This brings you to a menu-based interface where you can navigate with the arrow keys.
I think this is a turn of the millenium switch, and seems to be feature-rich for its time. VLAN capable, 801Q, SNMP, Radius, STP, Telnet, BootP support (!), and such like. Unfortunately, it is as loud as a jetliner... not so great if you live in a one-room apartment.