Help me identify a minicomputer from the 70s/80s?

Help me identify a computer from my childhood in the 80s! I've tried unsuccessfully over the years to try and identify this machine, and now, given all the retrocomputing interest and content on here, I thought I'd put a description out there and see if anyone bites. I was quite young at the time, so please excuse any confusion.

* The machine was installed at an elementary school, for kids that age

* There were 30-40 40 column terminals around the room. They were either green or three color. Very large text and rudimentary graphics.

* There was one classic WYSE style 80 column amber terminal in the middle of the room where the operator sat.

* Any time we wanted to play a different game or run a different program, we'd line up to talk to the operator, who would then key in a two digit terminal identifier and then select the program that we'd see from a menu.

* I think the system had some kind of branding around the name "super computer." I don't know if this was the hardware, the software or some value added reseller branding.

* The actual machine was 6-8' tall and made loud and distinct fan noises that could be heard around the room at startup which took several minutes.

* There was a tape system for taking backups, I believe it was at the top of the chassis (5-6ish feet off the ground and front loading with large tape casettes)

* The year I encountered this system was probably around 1985, I'm guessing the installation was probably between 1 and 8 years old.

* The school district used HP3000s in administration, it may have been one of these, but I don't think they had 40 column graphical terminals.

If you can identify this system, please pipe up!