Help identifying Mystery CDC Terminal...

Hey all -- Picked up an old dumb terminal (and I feel secure in calling this one "old") today at Re-PC in Tukwila, WA (I'm starting to really dig this place...). It's a CDC, labeled on the back as a "Display Terminal" (go figure), Equip. Id #CC5A5-A, Series Code 2, Part #15551800. I haven't been able to find any information on this beast at all on the 'net. I've put up some pictures here: http://yahozna.dyndns.org/computers/cdcterminal/ (Haven't had a chance to clean it up yet, so it's kinda smudgy...) My favorite thing about this terminal is the huge, backlit buttons on the front for Power, etc... very cool :). I've powered it up after giving it a check-out, and it appears to work fine. I haven't hooked it up to a serial line yet, but that's coming... maybe Linux has a termcap entry for this thing? :) Opening it up reveals repair tags with dates in 1974. There are four PCBs mounted inside, connected by a ton of ribbon connectors (there's no backplane to speak of). Looks like it's all TTL, though I haven't taken the boards out to investigate. Not sure I want to disturb them :). Anyone know anything about this thing? What's it capable of? What was it originally connected to?