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Little explorations with HP calculators (no Prime)
04-10-2017, 09:20 PM
Post: #182
RE: Little explorations with the HP calculators
So I'm slowly reading the general forum from the start, I'm at page 15 (of currently 81). I will likely need some life-factorial-extension to go through the archives of the previous forum (and after that I still will have the comp.sys.hp48 newsgroup and other forums to read).

Anyway I read an interesting post where one user, Alvaro, complained against stack operations. Now I'm not agreeing with him, I do remember when I played around with assembly that keeping the stack ordered was quite challenging, so I know that the stack is needed in certain designs.

The userRPL stack is gold in comparison with keeping order in ram. Still I find it not so ideal unless one provides a good commentary of the operations, due to the overhead in reconstructing what is going on. (there is also at least one nice thread about "how to comment stack operations" in this forum)

Anyway I recently find out, thanks to comments in other threads, about the free 42, that is a neat project. I checked the unofficial manual written in 2010 (with the occasion I thank the author) and I saw that the hp 42 and the free 42 are keystroke programmable in a way that closely resemble assembly.

There is a difference though, with the hp 42 one has, if I'm not mistaken, 100 registers that can be directly addressed. Those are quite handy to avoid all the stack manipulations to keep values available. Now as far as I know the equivalent of those registers in userRPL are global or local variables. I do not know any pattern to reserve part of the stack to variables that can afterwards recalled consistently, without actually creating any named variable. Am I wrong?

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RE: Little explorations with the HP calculators - pier4r - 04-10-2017 09:20 PM



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