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RPN scientific calculator firmware for $13 calculator kit
10-22-2019, 04:03 PM (This post was last modified: 10-22-2019 04:07 PM by jklsadf.)
Post: #25
RE: RPN scientific calculator firmware for $13 calculator kit
SDCC is indeed getting less efficient for the 8051, since it's no longer the focus of development. See for example this thread: https://sourceforge.net/p/sdcc/discussio...589cc8d57/

It is kind of sad, since I think SDCC was originally written for the 8051, but to be fair the 8051 is a pretty horrible architecture for programming in anything but assembly (in my opinion). The architectures Philipp says the situation is even worse for (the ds390, pic14, and pic16) are similarly fairly horrible for programming in anything but assembly (again in my opinion), so it's no surprise the compiler developers have moved on to "greener pastures".

I think fitting the CORDIC trig functions from the HP 35 is probably not easily doable with SDCC 3.5.0, without first freeing up space some other way. I was thinking of using some of Valentin Albillo's algorithms for the trig functions: http://www.hpcc.org/datafile/hp12/12c_Tr...ctions.pdf

Those functions use the taylor series expansion after range reduction/various trig identities, and the series expansion is fairly repetitive/should be less code space. The downside is it's probably slower.

Feel free to change the roll-down symbol on the template. It's one of the symbols from Elektronika calculators I personally like (the other being an up arrow for Enter). After you get used to it, it's a pretty good representation of what the stack does, although maybe a bit sacrilegious on an HP calculator forum. Rv is definitely more standard on HP calculators.
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RE: RPN scientific calculator firmware for $13 calculator kit - jklsadf - 10-22-2019 04:03 PM



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