This could be very difficult, but I'm trying to identify a kind of tape which went out of use 35 or more years ago.
This is doubly difficult because I don't actually know what the tape's intended purpose was... could be computer data, could be video, could be anything... All I know are the rough dimensions.
I first came across these tapes at school when the school library was throwing them out with a load of other out-dated equipment.
From what I remember, they consisted of tape (perhaps 1 inch thick) in a plastic cassette.
I am fairly sure there was only 1 spool inside, so must have fed into some kind of reel to reel machine?
They had large storage cases similar style to an audio cassette jewel case except they were square and much larger.
The approx size of the cases was about 5" x 5" square x 2" high. Black plastic back & sides. Clear plastic lid and spine.
I don't recall much about the actual cassette itself except vague memories of pulling foot after foot of tape out of it (because I was a destructive youngster and knew nobody wanted it). The tape was shiny and looked like video tape.
Anyone know what these could have been. I can't find anything on Google search that looks even remotely similar.
Good luck