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A successor to my slide rule

Posted by Aaron Chacon on 10 May 2004, 11:44 a.m.

Hello all,

I've been using HP's since about 1975, when my father got me a HP-25 for my first year in college. That was after my trying to take my Christmas exams with a slide rule. These days I think that I would have done OK if I had had a log-log slide rule, but that's a different post. I soon memorized the programming section of the manual and was continually doing data analysis for my lab courses on it. I still remember "do if true".

For some reason, the reverse polish seemed natural after using a slide rule. I'm not sure why, maybe because the slide rule does not have an "=" button, nor any buttons for that matter

Eventually I got tired of the -25 dumping all my programming every time I powered off, so I took one of my first paychecks and bought a HP-29C. That lasted several years until I went to graduate school and I bought an HP-41CV in the fall of 1980, after verifying that of what was available then, it was the most powerful hand-held. My programming had gotten to the point I needed the alpha display when the program was requesting data from the user.

I also got the X-functions and 2 X-memory modules. The biggest program I even ran on it was to do histogramming of grades for a class I was teaching. I split it into three parts so that each part could load the next out of X-memory. That was because one had to trade between program memory and main memory that held the histogram data.

My latest HP is a HP-32SII. I needed base conversions and the -41 does not have HEX. I programmed hex in the -41 at one point, but the fact that progams do not run until the key is let up makes the response strange. You see, I reprogrammed every key on the calculator so that it is truely is a hex calculator, rather than just writing a conversion routine to use on the results. I also have a program that does fractions in a similar fashion.

The HP-25 went to one sister who lost it, the HP-29C went to another, who lost that one. As far as I know, they never broke. The HP-41CV is still in use. I recently bought a financial module so I can figure out if a re-finance of my house makes sense. I am not sure what sort of factor it will have when the mortgage broker is figuring stuff out on an HP-12C and I pull out the -41, but it could be fun.

Aaron Chacon

P.S. By now someone has thought that the -41CX can run re-assigned key programs when the key is pushed rather than let up, which would fix the problem with the -41CV. I am thinking about aBay even as I type this.


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