SwissMicros DM42

Yes, I have a desktop calculator primarily because I like using RPN, and there are very few software RPN calculators _that aren't just HP emulators._ In a pinch I will use PCalc in RPN mode on iPadOS, and Droid48 on Android, but those just can't beat the tactile sensation of real buttons. I bought a SwissMicros DM42: the build quality is great, the e-ink display works really nice for a calculator, and it sips power compared to more recent graphing calculators. (I've had this thing for over a year and it's still showing a full charge on the CR2032 battery it shipped with. My HP 50g used to demolish a set of like 3 or 4x AAA batteries every 2-3 months.) My only complaint is the rubber feet have exposed my office desk as not being a truly flat surface.[1] (I also have access to an HP-15C (both the original and a clone), but I like being able to see the whole stack in XYZT mode. I have no mind's eye, so seeing only the one register is torture for me.) [1]: https://www.youtube.com/watch?v=3ji41DzipIU

I already own the SwissMicros DM41X, DM42, DM15L, and DM16L. Excellent quality devices, and built like absolute tanks! Picking up any of them will leave you astonished, a DM41X (or DM42) with its anodized metal back plate feels like it weighs at least 2x a TI-89 Titanium. I have as many of the HP-41C module files as I could find on MoHPC and other sites stored in my DM41X. They are all very high quality devices, I can't recommend them enough!

I believe they made improvements to their keyboards in recent years. My DM42n has a decent keyboard. Main criticism compared to my HP48G is that the keys are on the small side.

HP did license out the manufacture of 12cs at some point so if it's not a counterfeit it is almost certainly a manufacturing error by some licensee. Note that the 12-c is one of a legendary "voyager" series of HP calculators which have that landscape form factor and are highly prized by collectors. There is an HP15-C scientific calculator equivalent and a 16-C which is supposed to be for programmers so does the sorts of things we programmers do all the time like converting things from hex to octal etc. It has built-in support for bit twiddling and shifting operations too. If you ever see a landscape-style "voyager" HP calculator in a junk shop or whatever and it's not a 12-C (because they are quite common) it's quite rare and may be worth buying and reselling if it's in usable condition. I have 2 HP-12c calculators which I bought while I worked at Goldman. One was always on my desk at work and I had another at home. I can certainly confirm they were common in finance back in 2000-2009ish. That said even back then they were being replaced by non-RPN calculators for a lot of people and only people with nostalgia and the hardcore had a 12c. They're incredibly robust - famously a zookeeper once used an HP12-c to calculate proportions for animal feed, dropped it into the mix and it passed through the digestive tract of a hippo. It was still able to calculate the yield to maturity of a bond after cleaning. In addition their batteries last forever. Even though the versions I ha…

I've used the free42 (and newer plus42) app on my phone for nearly a decade now. In the UK, RPN calculators were pretty much not seen in the school place. We had Casios, Sharps, and those really into maths tended to get TI graphing calculators. The beauty of RPN is that you can get the data into the calculator before you figure out how you're going to calculate the thing you want to know. The roll and x<>y help you to manipulate the data, and once you get the hang of it, algebraic notation feels slow and unintuitive (back pedalling through notation to get brackets in place for example). You also get intermediate results to sense-check as you're going along. I recently got a DM42 from swissmicros, which is a real life calculator running free42. It is beautifully made, and it makes me happy that I have it. But my job isn't in one place, so I still probably use the phone app more.

Aside from keyboard not being quite at HP level (but then which one is? And it is still good), DM42 is entirely better version tbh. Even works with printer! Weird obscure fact: The printer head for HP calculator printer was still available as new parts as late as 2019, coz it was used in variety of devices, I bought cheap non-working one and just replaced the head