The Comptometer 992 mechanical calculator

The Comptometer 992 was an electrically driven version of the model 3D11, both made in the 1950s. It has a very quite electric motor, and was advertised with the slogan Floating Touch, referring to its light key action.
For more information about this and other machines in my collection, please visit my website:
www.jaapsch.net/mechcalc/
0:00 Introduction
1:14 Clearing
1:22 Addition
2:10 Decimal markers
2:30 Subtraction
3:10 Controlled Key mechanism
4:15 Outro

[@stephenfreeborn]

Yeah, it’s a great machine. I like how they just stuck with the same design and refined it. No need to add a lot of bells and whistles. Cool device. Weird safety.

[@ChrisStaecker]

And it actually works! Very nice- I always thought an electric comptometer was a silly idea but actually this one seems to be quite nice. I imagine you really could work faster on this one than on the manual models.

[@jaapsch2]

Yes, it works surprisingly nicely. All the keys are equally light in their action. Since recording this I have taken out all the keys to properly clean the keyboard, and it now looks barely used.

[@TaramiBedona]

I wonder if the partial press safety is still there to placate set-in-their-ways users. As you mention, Compometers had been around so long - virtually unchanged - that people had used them their entire career, for tens of thousands of hours. That safety possibly provided some level of psychological safety the users craved.

[@jaapsch2]

Good point, well made. I had not thought of it in that way, but that could very well be the main reason for it.

[@drfrancintosh]

I received a model B for Christmas and I'm excited to play with it. But the handle on my clearing mechanism is bent. I'm afraid to bend it back for fear of snapping. I wonder if you have any suggestions on how to fix it - or how to find a replacement handle.

[@YamamotoTV2021]

Could you please explain, how does the mechanism on this machine work? How does the machine distinguish between a filled-in zero and an unused zero?

[@nickxyzt]

I am very curious - if it's not plugged in and you type, how does it behave? Does it still add?

[@jaapsch2]

No, nothing gets added if there is no power. I'm not sure what happens if you then switch it on, i.e. whether the keys pressed while off are "remembered", but I can't try it out right now since this machine is in storage.

[@hellomcflyy]

floating touch....heh