@kewpie saidI had a Hewlett-Packard pocket programmable scientific calculator, which used reverse Polish notation (no = key). Great little instrument. RPN did not catch on with the unwashed masses though (“where’s the = key!?” ).
You must be the same age as me. The college made us queue to punch our own program packs. The error was always in the first couple of lines so you got pages full of error messages.