"In today's video, we'll take a look at my grandfather's vintage HP-45 #calculator from 1973"—so he opens.
As an #EE who used #HP #RPN calculators for my whole career, that word, "grandfather", hit me hard.
Anyone else ever used a #rpn #calculator? I've been using a #SwissMicros DM15L and I LOVE it soooo much. One of the best calculators I've ever used.
Fighting Words
The #HP-15C (the original #Voyager Series) is, far and away, the best #engineering #RPN calculator, on balance: capability, size, shape, quality, durability, aesthetics.
OK, in a more civil tone, I realise my 15C is significantly less capable, in one way or another, than my 41CX, 32S, 28S, 48GX, 35s, Prime, ....
But why this irrational adoration?
Well, you'd know, if you're an engineer of a certain age who used calculators in your daily life.
@AmenZwa Agreed! My #RPN #calculators are a HP-12C, DM16L, DM42 and HP Prime. I also use Free42 on my phone.
Fighting Words:
If you, like me, are still using #calculators in 2025, the only sensible input method for such ingenious devices is the equally ingenious Reverse-Polish Notation (#RPN), and the only acceptable manufacturer of such devices was the original Hewlett-Packard (HP).
Vintage #HP RPN all the way, baby! Ah well, OK; new #SwissMicros RPN, too.
#free42 une super calculatrice HP #rpn customisable ! Et quelle puissance !
Ça nous replonge dans les années d'autrefois !
#geek #calculators #linux
In my career as an #ElectricalEngineer #EE over the past four decades, I've used several #HP #RPN #calculators (yes, only RPN). Of all those, my absolute favourites, in descending preference, are these:
• HP-15C
• HP-41CX
• HP-32S
• HP-35s
It's the last day for my Black Friday sales - everything is 50% off today!
PCalc, my highly configurable scientific calculator with #RPN support, is only $4.99 USD.
iOS / iPadOS / watchOS / visionOS:
https://pcalc.com/store/pcalc
macOS:
https://pcalc.com/store/pcalcmac
Dice by PCalc, my 3D physics based #TTRPG dice app, is only $0.99 USD.
iOS / iPadOS / watchOS:
https://pcalc.com/store/dice
macOS:
https://pcalc.com/store/dicemac
Note that I actually say what my apps do, unlike my previous posts! #marketing
My friends on #MathsTodon.xyz know that I'm a nut for the #HP #RPN calculators, specifically the HP-41CX, HP-15C, and HP-32S. But, out of curiosity, I added the HP-48SX to my collection a couple of weeks ago, because I got a fresh one on eBay for cheap.
As many HP RPN calculators fans know, the 48SX is quite advanced (a worthy successor the inimitable HP-28S graphing calculator), but with a horrid, low-contrast display. Nevertheless, since the 48 postdates my career by more than a decade and I've never used one in anger, I couldn't resist this cheap thrill.
NB—If you're looking for the most advanced HP RPN calculator, look no further, it's the HP Prime. But if you're seeking the most advanced in the classic line, that's the HP-48GX. After several days of playing with this 1990s peak performer, I'd gladly stay with my 1970s king, the HP-41CX.
https://amenzwa.github.io/stem/ComputingHistory/HowRPNCalculatorsWork/
@Wintermute_BBS Wow, if I remember correctly, that was the first compiler I ever bought. Forth is awesome! #RPN
Here's me: (#introductions)
I'm mostly about #retrocomputing and #computerhistory with a bit of #vintagecomputers thrown in. Also #calculators especially #rpn and programmable. I like #space and science and history. I read a fair bit of fiction these days, including #sff. I like languages, human and computer. I'm from the 70s culturally, 80s technologically but the 60s biologically. I avoid talk of current events. I try to use CWs and to be an ally.
I co-moderate
https://retrocomputingforum.com
Not using Cornu spirals, but cool to see PS in the wild.
la .samflir. 
