An HP 50g was my calculator of choice, and the whole RPN style really rubbed off on me. Plus it had more advanced symbolic algebra capabilities than a ti83 equivalent. I enjoyed learning common lisp, scheme, racket, etc through high school and college and still am fond of them today because of this calculator.

Most if not all high schools and colleges in the US required TI “graphing” calculators for algebra/trig on up. I don’t know if they still do. I never saw this HP28, sounds awesome!

The rest of the world only has Casio, I think.