I found this calculator in 2025, in the office of an abandoned silverware factory. I usually don't take anything from these sites, I'm more of a photos only kind of person, but it broke my heart to see it there, subjected to the dirt and rain and mold, next to another one of a similar model that had been smashed with a blunt tool. So I took it home, and spent a few days cleaning it and making small repairs.
When I switched it on for the first time, it came right to life. Except the number barrel on the printer kept rotating over and over again until it was switched off. I forgot excactly how I fixed this, but there were a lot of problems with the printer. There was some sort of sensor that wasn't registering any input, because a gear was broken. I broke the gear completely apart and epoxied it back together with the spindle, and I think there was a tab that had to be bent back in place? There was also a good heap of dried ink gumming the whole thing up. Unfortunately the printer will likely never work again, fully, because the number barrel is heavily damaged. But the rest of the printer operates fine, you can hear the shifting, clicking noise of it trying to print out the calculations. I will probably put some paper in it at some point just to see what happens.
The only other problem with it is the decimal key, sometimes it prints a six instead. This is mildly amusing, I might fix it if I can, but I don't have much of a problem with hitting Clear Entry and moving on when it does that.
I would love to talk about how it works, but this kind of tech is a little too advanced, I don't really understand it yet. But I love the vacuum fluorescent display. It's so pretty and stands out while being very easy to read, even from a distance. The tinted cover gives the illusion of the numbers floating in a void, and if that cover is removed, you can see the phosphors (I think) of each number and symbol through the glass. I read online that these green VFDs can last tens of thousands of hours, which is really durable! There's no way of knowing how many hours it has now, but I make sure to turn it off when I'm not using it so it can have as long a life as possible.
It's interesting to me to think about the story of this device, it was made as a tool to make accounting easier, it served for an unknown amount of years at the silverware factory doing just that, possibly even recording the downfall of the place on its 2.25 inch strips of paper. And now it's on my desk, helping me with my own accounting. I am glad I happened to be there to give it this chance before it was too late.
Here's a short video of me operating the calculator, punching in random sequences of numbers. Video
Click on an image for a high resolution version
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Page taken from a 1983 Texas Instruments catalogue |
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Disassembled to show all circuitry |
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Close up of the main circuit board |
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Office in which it was found |
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As it was, before repairs. In surprisingly good shape |
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Close up of the printer gear train, with the broken gear visible |
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The rubber cylinder with the numbers had cracked, some pieces fell away leaving large gaps and numbers missing, that part is not pictured |
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Blue key switches! Not disassembled further, though that may happen later |