HP RPN Calculators

The DM42 and calculator musings by Tim Gray

So first, why the heck do I even need a calculator? How does someone my age end up using a calculator when iPhones, Wolfram|Alpha, and Excel exist? And why would I spend a decent amount of cash on a physical calculator based on a 30-year old design and not buy a much cheaper and more capable modern design?

This will be a long and rambling post… you have been warned.

Tim Gray's post was a short trip down memory lane.

These days, I don't have much use for a scientific calculator, much less one that uses RPN (reverse polish notation). However, when I studied electrical engineering at Georgia Tech in the late 1980s, the HP and I were inseparable. I would not have made it through my basic electrical engineering courses without my HP and RPN. My HP was a gift from some friends at Drew University (where I was studying Physics), who wanted to be sure I was prepared.

I think my HP 28S (or was it an HP 48S) is somewhere under a box under another box under yet another box at my mom's house in Florida. Or maybe they were tossed decades ago. I do have 42s RPN app on my iPhone.

NOTE: I looked around the house and I found my dad's HP 12C. He was an accountant.

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  • the
    28th November 2019 at 5:16 PM

    @ronguest Of course PCalc can’t emulate those wonderful HP tactile buttons, can it?

  • khurtwilliams
    28th November 2019 at 2:22 PM

    @BestofTimes love the look of the NIkon FM3 you've listed on that page. I've got an Asahi Optical Co. Spotmatic II

  • BestofTimes
    28th November 2019 at 10:00 AM

    @khurtwilliams I bought the Swiss Micros DM42 a few years back and it’s listed on my “Stuff page’. I still find it so much easier to grab a calculator with a keyboard layout I know intimately rather than Excel or an app.

  • ronguest
    28th November 2019 at 7:37 AM

    @the It does and I use it, as well as my HP.

  • the
    28th November 2019 at 1:03 AM

    @ronguest Doesn’t PCalc have RPN?

  • khurtwilliams
    15th August 2019 at 8:55 AM

    @ronguest I miss those days when I felt like a "real" engineer.

  • ronguest
    14th August 2019 at 2:23 PM

    @walter Agree on the batteries - they last years and years and years. Unlike modern devices.

  • walter
    14th August 2019 at 1:25 PM

    @khurtwilliams @ronguest hp 12c. Once I learned how to use it, wow. I don’t use all the buttons anymore, but it’s there when I need it, battery lasts for years and it feels solid in hand. For the true experience, buy an old one on eBay, the current version has a lot of plastic.

  • ronguest
    14th August 2019 at 12:20 PM

    @khurtwilliams I’ve used my HP 12c my entire life. Not so often these days but I find it often much easier to use than PCalc on my iPhone or iPad. I find it really hard to use a calculator that doesn’t have RPN.

    • Khürt Williams
      15th August 2019 at 12:00 PM

      @ronguest I miss those days when I felt like a "real" engineer.

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