My first big project was also done on a similar calculator.
A few years before the TI era there was a strong HP-48 scene in France and I believe that many of the early work and games on TI-8x and T-9x were inspired by what was already available on HP-48.
A few years before the TI era there was a strong HP-48 scene in France and I believe that many of the early work and games on TI-8x and T-9x were inspired by what was already available on HP-48.
Here is my own contribution at the time: https://www.hpcalc.org/hp48/apps/shell/
A multitasking alternative OS and a few apps, I learned a lot working on this.