RPN Calculators

Tim Wescott · 2013-02-04T23:48:25+00:00

Just got this from my kid: "Also, a cool birthday present would be an RPN calculator with a three-stack display, stack switch, and variable base log. Or even any (non-graphing) calculator with variable base log function (realcalc is nice, but only has log base 10 and log base e, and I don't like my graphing calculator. Also I can't use realcalc for tests)." Does anyone even _make_ RPN calculators any more? Or any variable base log non-graphing calculator? And yes, I am going to tell him to suck it up and accept that log_x y = (ln y)/(ln x) is so easy that a variable-base log function is probably not in the cards. -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software

Feb 04, 2013 65 Replies

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mpm 13 years ago

I really miss my HP41CV. The replacement HP48 is more capable, but it's always been a rocky marriage. :(

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Roberto Waltman 13 years ago

They did the right thing. Once.

"Developer kit for HP 20b financial calculator"

"This kit is designed for developers who want to re-purpose the HP 20b and reuse the platform for other purposes."

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Roberto Waltman [ Please reply to the group, return address is invalid ]

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mi 13 years ago

Anybody know if the keys are of the old HP quality ? If they are, I'll order one for sure!

Mikko

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josephkk 13 years ago

misstep

0001

I have known people that had the tools (provided by HP) to get into the machine code for the 48. Another case where they opened up.

?-)

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mroberds 13 years ago

I know I'm a little late, but: HP 48G / GX / G+. They seem to go for $30 to $70 on Ebay. Not quite sure what the differences are, but those were the last models of the "classic" 48. My 48SX from circa 1991 is still chugging along; it's on maybe its third or fourth set of AAAs. They are from before the clue fire went out at HP, so they will keep working for a long time.

I used it at work two years ago to figure out a problem that required a

48-bit word size; a 48-bit number was coming out of an FPGA and then being (incorrectly) converted to a 64-bit number in C. None of the "desktop" calculators I tried, Linux and Windows, 32 or 64 bit, could handle this correctly. The HP can do anything from 1 to 64 bit word size; mine helped me confir that the program was indeed screwing up and what the fix was.

Matt Roberds

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krw 13 years ago

The 'X' models had expandable memory and the '+' had more memory on board, according to Wiki. I may investigate eBay. Thanks.

I had a problem with binary calculators when doing some 2-D filters in an FPGA. None handled binary fractions properly, with the exception of one app for a Palm Pilot and it wasn't RPN. :-(

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