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This plain calculator has a green fluorescent display and uses four AAA batteries. One thing that struck me about the the TRIUMPH 81C and the TRIUMPH 81S are their distinctive smell. I’ve seen more than one of these calculators and all of them have this smell.
Identical to the ADLER 81C.
The way this calculator must be operated is puzzling at first. Multiplication and division work as expected, so to multiply "6" by "7" for instance, simply type "6 x 7 =" yielding "42". To add something, say "8", to this result the usual sequence "+ 8 =" does not work, the result displayed would be "8". Adding and subtracting works in a different manner. To add "8" type "+ 8 +". To subtract "8" type "+ 8 -". Having added or subtracted a value, simply type a value followed by the + key or the − to add or subtract that value. Use the + key to add the same value again, or use the − key to subtract the same value again.
Slide the "Σ"-slider to the right to change the = key into an M+ key. I do not really see why this is an addition to the workings of the calculator since there already is an M+ key. A non-zero value in memory is indicated by a period in the leftmost digit.
Use the "F 2 3" slider to switch between floating point, or rounded currency modes with a mantissa of two or three decimals.
To change the batteries the metal cover can be slid upwards.
The calculator on display here is the first calculator I ever owned. It was given to me in a broken state by Theo van de Ros, a good friend of my father. Thanks, Theo. I took it apart to try to figure out how calculators work, and also to try to fix it. The problem was the keyboard, took it apart and cleaned the contacts which wasn’t all that easy because there’s a spring behind every key! One bad movement and all the springs jump out of the calculator. At least that is how I remember it! :-)
I really loved this calculator at the time. Took it with me everywhere I went. I remember being on holiday with my parents, somewhere in the 1970’s and suddenly one of the keys didn’t work anymore. Took it apart on the hotel bed, springs everywhere!
I also remember looking into the fluorescent lights in the dark and seeing, for the first time, the little cathode wires glowing. And the sound it made when switched on (the little transformer for the higher voltages of the fluorescent display).
I will stop now. By now it should be clear that weren’t it for Mr. Theo van de Ros, this site here probably would never have come to be.
My TRIUMPH 81C doesn’t work anymore and the "Σ"-slider is missing (lost, in a hotel bed maybe?), but considering what it brought about it’s on display anyway. I do have other specimen, maybe I will one day scan one with a working "Σ"-slider.