At some point during school (between 1992-1995) we started to learn different programming langages with my friend, starting from Basic and Pascal and ending with x86 assembler.
I also happened to have ZX Spectrum at home and it's always interesting and motivating to try something practical, so picked something which seemed easy and fun: https://spectrumcomputing.co.uk/entry/4803/ZX-Spectrum/Stack_Up and tried to more or less clone it in Pascal.
Based on code comment, this happened in '95 :).
Usage:
dosbox STACK_UP.EXE