I worked with some earlier systems that were tape drive only models as well. I think I was in like 4th or 5th grade at the time and only kids in the GATE program had access to them. I think it was like the next year that the first 5.25" drives started coming out.
Oh, yeah, similar situation - the Commodore 64 was my first computer, but the first I had access to, because I was in the TAG program, 4th-5th grade, was at school, a TRS-80.
We had a Model I and a Model II, as I recall. That's where I first learned BASIC, and, of course, being a kid, attempted to write a game or two outside of the stuff I was supposed to do with the system.
The tape drives didn't even have to be specific to those computers like the Commodore required. They were standard tape recorders, and just plugged in through an audio jack.
Loading and saving sizeable (for the time) programs sure gave you a lot of time to sit and think. 😆