RPN83P: RPN calculator for TI-83+ TI-84+ inspired by HP-42S

[jthole]

Thanks again for a very useful update! (complex numbers)

The TI-84 already has a workable algebraic solver / root finder / integrator, so I personally would find simple keystroke programmability more useful than a solver / numerical integrator.

I would like a well defined API (e.g. through the LastX and register variables) between RPN83P and TI-Basic, but I can imagine that being low on the priority list.

Regarding unit conversions, it would be great if there were a few "free slots", so that users can define their own unit conversions (but that requires some kind of programmability).

My own opinion regarding matrices is the same as with the solver and numerical integrator; there already is a matrix editor, and matrix math, available in the native TI-xx interface. I would be happy switching to that level for matrix calculations.