While I don't have a story quite like OP's, I wanted to share my experiences with old-school programming in more recent history. In middle and high school (2008-2014), I had access to modern hardware, the internet and all those lovely things at home. At school, though, I didn't have access to a computer most of the time, and yet I wanted to program. What I did have though, was a TI-84+SE graphing calculator, with a z80 cpu clocked at 15MHz and 24/128K accessible/total RAM, and 1.5/2.0MB of ROM. Most teachers didn't really care if I just stuck my nose into that thing for the entire class, so often I did just that.

For those not familiar with the calculator, it ships with an OS that provides a shell where the user can input mathematical expressions, as well as a graphing interface. It also provides a program editor where the user can write what are essentially shell scripts for the main interface in TI-BASIC, or run machine code written in hex if the program starts with the AsmPrgm token. It also lets you transfer files from a PC using a usb port on the calculator. You could download and install "Apps" for the calculator. When I was 12-14 I mostly wrote small programs, like Pong and a quadratic factorization utility, in TI-BASIC, and played games that I downloaded in class.

After a while I tired of TI-BASIC because it was slow, and that limited the possibilities. I downloaded Axe, an App that modifies the code in RAM of Kernel's TI-BASIC editor to allow for programs written in a different language, which was basically assembly + a lot of macros and a standard library useful for writing games, or like C without a type system. This code was compiled to machine code on the calculator, and therefore the code ran at a reasonable speed (keep in mind it's still just a 15MHz cpu from the 70s).

With Axe I made some more interesting programs. Unlike with TI-BASIC, where learning the language was easy since the calculators main interface was basically a REPL for the programming language, Axe was hard to learn. I needed to look at external documentation to know what I was dong in Axe, but even though I had a smartphone at this point, I couldn't use it in class, so I printed out the manual to reference it in class. I wrote a bunch of programs in Axe, like a cellular automata simulator, a game of life program, a 4-level grayscale sprite editor (which worked by flickering the pixels of the 1-bit display which had a slow enough response time to create a static gray color if alternated quickly enough). I also learned z80 assembly and used an on-calc assembler and editor called mimas, but editing assembly on-calc was too bothersome with a 64x96 display, so I mostly stuck with Axe.

Eventually I stopped being the nerdy kid who played with his calculator all day, but I had fallen in love with the platform, so even though I wasn't writing code in class, I wrote code for the calculator at home, sometimes on my PC and sometimes on the calculator just because I liked that experience more.

I'll be sad to see these ancient calculators finally phased out of the math curriculum in the US, so that kids no longer get access to that last stronghold of 80s computing. Raspberry Pi is cool, but it's still so much more modern than the calculators, which hurts its coolness factor for me, but more importantly, kids won't have access to it unless their parents want them to get into computing. Soon I see kids only having hardware that seems impenetrably locked down, which is a real shame.