Museum of Pocket Calculating Devices

https://www.calculators.de/

Comments

lapetitejortMay 21, 2026, 5:41 PM
My dream is to one day own a Curta. I want to find an algorithm to approximate pi, one crank at a time. I had a chance to hold one at a vintage computer festival once. Smaller than I expected. Truly pocketable.

I just had a thought. Why hasn't a Curta simulator come out for the Playdate? I guess I am cursed with creating it

pugworthyMay 21, 2026, 6:27 PM
I found a Thacher Cylindrical Slide Rule [1] in the garbage once at the university I worked at. I didn't have a holy grail list for such things, but it assumed that role when I found it.

[1] https://americanhistory.si.edu/collections/object/nmah_11312...

tavavexMay 21, 2026, 6:24 PM
The Curta is the ultimate calculator to own. I wish someone was still making modern replicas, but it seems that it's just too complex or at least too complex to bother with. So we're stuck with scavenging the ones that are still working off of individuals. I hope to buy one someday if there's still any supply of them left on the used market.
MirasteMay 21, 2026, 10:57 PM
There is a wonderful teardown of it here:

https://www.vcalc.net/CU-Disassembly/

Scrolling through that makes me think it's extremely unlikely to be replicated commercially. I can't imagine how much machining all of those parts would cost.

bell-cotMay 22, 2026, 1:13 AM
For those unfamiliar with the Curta - https://en.wikipedia.org/wiki/Curta
HackbratenMay 21, 2026, 8:31 PM
I'll buy it if you ever follow through!
idatumMay 21, 2026, 6:41 PM
I have 2 listed: HP-35 and HP-41CX.

Still use an HP-11c.

Will die on that hill defending RPN!

TacticalCoderMay 21, 2026, 11:19 PM
We had HP ones at school, lots of fun in math classes...

But then I still have my Casio FX-850P, which I probably own since 1989 or something. Last time I put batteries in it (5 years ago?) it was still working. It's in TFA : )

https://en.wikipedia.org/wiki/Casio_FX-850P

It's on my desk, always visible. Next to an Atari Portfolio (the same one young John Connor uses to hack doors in Terminator 2) and a totally beaten up ZX Spectrum. Remnants of a glorious past.

BlackstratMay 22, 2026, 12:47 PM
Cool page. I still have a working TI SR-51 from the early 70s, probably 74, maybe 75. Blew several hundred dollars on it, only to learn that the university I attended only allowed slide rules. So it goes. Despite the rather primitive red LED, it still works. Better than my slip stick actually. It's amazing the circuits that fail on a slide rule.
kfichterMay 22, 2026, 4:57 PM
Missing the venerable PF-8000!

Weird little device with a "touch screen" and character recognition.

https://www.computerhistory.org/revolution/mobile-computing/...

BarbaryCoastMay 23, 2026, 10:49 AM
What a horrible web site. I hit "reload", and I now have two copies of the LH Menu. In IFRAMEs. I was able to see a couple of the items, then that broke. I click and nothing happens.

Some people just can't be trusted with HTML.

ofrzetaMay 22, 2026, 5:24 AM
So the guy in Solingen/Germany (Gerhard Wenzel) is real and owns this collection but the museum is strictly online https://www.techbook.de/mobile-lifestyle/taschenrechner-samm...
asdefghykMay 21, 2026, 8:52 PM
As someone whoose first calculator was a basic Sharp (I think) 4 function model in 1975 - I admired the scientific calculators that others could afford, at that time. This site bought back memories of the early era calculators.
polishdude20May 22, 2026, 8:30 PM
One category of calculator they're missing is "Food Based Calculator". Imagined the front panel of a calculator being made out of a Graham cracker.
cestithMay 21, 2026, 6:31 PM
I have a few pocket computers not on that page. I guess I have a new option where to donate them if I ever decide to part with them.
gregsadetskyMay 21, 2026, 8:46 PM
See also https://vcalc.net/
asdefghykMay 21, 2026, 8:59 PM
This website, thru one link and another lead me to (The rabit hole of ) "mechanical calculators". A mechanical marvel for me.
NetMageSCWMay 21, 2026, 7:45 PM
I was really looking for watch calculators.
Analemma_May 21, 2026, 9:17 PM
They have that on the page: https://www.calculators.de/

Although one omission I was hoping to see is slide rule watches. It's unfortunate that these days mechanical watches are just status symbols for rich people, because back in the day slide rule watches like the Chronomat and Navitimer were tools that people really needed for their job. Navy test pilots said their Navitimers were indispensable.

maxy_etcMay 21, 2026, 10:35 PM
this is the way websites should feel
zvrMay 21, 2026, 7:09 PM
As the old joke goes:

"For your birthday, I wanted to get you a pocket calculator ... but then I thought you'd already know how many pockets you have."

ConanRusMay 22, 2026, 12:12 AM
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