I had one of those in middle school c. 1990. It had function and program support. The problem with modifying one of those would be it's physically small and lacks I/O.
Upgraded to an HP 48GX sophomore year of high school. It worked well for math and physics coursework, AP Calculus BC, and the SAT-I math section. The IR serial port's LED was so powerful, there was a learning TV remote app that could control TVs from ~60-100' (20-30m) away. The ability to beam software to other calculators was just shy of the invention of the app store.
Upgraded to an HP 48GX sophomore year of high school. It worked well for math and physics coursework, AP Calculus BC, and the SAT-I math section. The IR serial port's LED was so powerful, there was a learning TV remote app that could control TVs from ~60-100' (20-30m) away. The ability to beam software to other calculators was just shy of the invention of the app store.