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Wow- what a tribute to this very cool calculator

Posted by Dale Gombert on 19 Aug 2004, 11:30 p.m.

One day in 1980 (?), my physics lab professor was out sick, and we had a substitute. He seemed interested that I had programmed the 41C to prompt me for lab results as the lab went on and then do the analysis and spit out the answer. I was done halfway through the lab, and he took me aside for a chat. He borrowed my calculator, slapped on the card reader, and ran a card in. He had put in the game "Hangman", and told me to come back whe I figured out how to program the statement "STO M".

Well, I never figured it out. But I came to him anyway, to find out how he did it. He told me that he had heard of a challenge from HP to "make the goose fly backwards". He succeeded, impressed HP, and was offered a job with them. That lab was just days before he left U of MD for Oregon.

Prof. William C. Wickes left me a signed copy of his book, "Synthetic Programming on the HP-41C" as inspiration.

I used the calculator to reverse calculate the positions of the planets from the NAV PAC. I was a planetarium director at a near by community college, and the orrery had five little flashlights to project dots for the planets. I had to position the beams before each showing, and the calculator allowed me to do that.

The only product I ever made for it was a reversible overlay made of paper. They were designed to be cheap ($2 for 10 cardstock paper, or 50 20-lb paper). If you really liked the assignments, I recommended using plastic letter transfers (like "Letraset" brand), then spray-painting the overlay with an acrylic paint to seal it. I still have a pile of those overlays, and a few clear plastic ones that were an experiment. They came out okay, but dulled the die quickly.

At a convention in PA, I bought a small light that plugs into a module port, for use at night - those were another third-party product. While a member of the PPC club, I also scored a PPC ROM. I still have about two dozen issues of the newsletter.

I still have my CV, my wife has hers, and I got one for work from a colleague who couldn't figure it out. Aside from our Time and Nav Pacs, we still have my wife's wand, but my card reader seems to have finally conked out. Alas. I am gathering the courage to try the fix posted at your museum's web site.

Thanks for the web site!


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