Monday, November 21, 2011

For Large Numbers!

For large numbers, why not a large calculator? The photo is of a Sperry Remington 1209 I was given several years ago. Next to it is a modern pocket calculator and a book of matches to serve as a reference to show how big this thing is. I'm not sure of the age but I'm guessing this calculator was made in the late 60s or early 1970s. Also, it plugs into the wall; no batteries.

When I find my toolbox I'll post some more photos as the inside of this calculator is way more fascinating. The 12 digit display, instead of being a single panel like a modern calculator display, is actually 12 separate vacuum flourescent display tubes; one for each digit. Also, each key actually has a magnet directly under it and a glass tube containing two pieces of metal. When you press a key down, the magnet gets close to the glass tube and pulls the two pieces of metal in it together to form a complete electrical circuit. Primitive and facinating at the same time, I think. This calculator, with such a design, must have cost a fortune to build.

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