It was essentially a word processor is my guess. Although, it probably had some computing skills too. A giant, 12 pound calculator. This article brought back to mind the typing class I had to take in middle school. Did you have this too? It wasn't called "typing" though it was called "keyboarding". I remember being proud that I was one of the fastest in the class. I really enjoyed typing... still do. It's pretty amazing how little I write with a pen/pencil these days.
Keyboarding. Ha. I mentor a lot of young students at work (by young I mean high school-undergrad age). I'm not that much older than them, but the idea of keyboarding to them might as well be carving on stone tablets. I'm not a terrible typist, but these kids, who have been IMing since they could talk, have the typing skills of an advanced secretary. But alas, they'll never know the joys of counting the number of characters in a line of text so that you can backspace half that amount from the center of the page to get centered type. What a skill that turned out to be; thanks public schools!
A computer is essentially a calculator (as the word says), so my guess is, even tough the target group probably didn't use it, it could also do lots of other things. Like huge calculations, games and even some surfing and networked working. The internet didn't exist yet for general use, but smaller networks like Telenet, Tymnet, Merit Network, ARPANET etc. were in use since the 60s/70s.