Until fairly recently, I had never heard of Curta calculators. These little mechanical marvels were invented by Curt Herzstark (1902-1988) in the late 1930s, and from the late 1940s until the early 1970s they were popular portable calculators. Eventually, they were replaced by portable electronic calculators.
Due to their shape, the Curta calculators were nicknamed “pepper grinders” and “math grenades”. In all their mechanical intricacy, I find them very sexy machines. If you want to have an idea of how these calculators work, take a look at this video:
or at Jan Meyer’s amaxing Curta Simulator.
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Some links:
- The CURTA Calculator Page (by Rick Furr)
- The Amazing CURTA! (by Bruce Flamm)
- Curta Calculating Machines (by Greg Saville)
- Disassembling a Curta Calculator (by Greg Saville)
Tags: Computers, Curt Herzstark, Curta, Curta Calculator, Mechanical Computers, Mechanical Devices, Vintage Computers
September 10, 2008 at 22:50 |
Slide rules are also mechanical computers, right? And they are portable, too.
Therefore, Curta calculators were NOT the most popular portable calculators before the advent of electronic calculators, slide rules were. Curta calculators may have been the 2nd most popular portable calculators, though.
September 11, 2008 at 22:34 |
Very interesting. And slide rules are analog calculators, while the Curta is a digital calculator, if that makes any difference to anyone.
I’m not 100 percent sure about this, but I have a vague feeling there was a Curta in the display case with the slide rules in the Georgia Tech bookstore in the Fall of 1971, when I would first have visited the store. I know I bought my Pickett slide rule there that year, and the following year, I think, they were selling their first HP-35s.
I wonder if someone could build a pocket version of a Difference Engine?!
September 11, 2008 at 23:20 |
Indeed, slide rules are analog, Curta calculators are digital. Building a portable version of the Difference Engine would definitely be cool. One would probably need a magnifying lens to check the result of the computation ;-) Well, someone has built a LEGO difference engine (not portable, but also cool).
My father went to college in the early 1970s, just like you, and he still keeps his old slide rule, and his pre-historic Texas Instruments calculator.
I think mechanical calculators age much more gracefully than electronic ones. Curta calculators might be decades old, but they are always cool, they are vintage calculators, they are works of art. Most old electronic calculators are not vintage, they are just obsolete. I guess this has to do with the fact that in mechanical devices one can actually see the calculation taking place… right before our eyes. In electronic calculators, computation is not visible, and thus, it’s not as appealing.
September 11, 2008 at 22:12 |
I learned about these in William Gibson’s novel Pattern Recognition. Intriguing.
September 12, 2008 at 21:14 |
When I was a kid, I got a calculator of sorts from a variety store. I think it cost less than a dollar. You’ve probably seen one. It’s a flat metal and plastic rectangle with parallel metal strips inside, each strip numbered vertically and the “calculator” is numbered vertically alongside each strip. At the start, the zero on each strip is revealed in a “readout” cutout.
To add, say, 432, 8879 and 23, you’d begin by using a stylus (or the tip of a ballpoint pen), putting it into a notch at the “four” position of the hundreds-position strip and shoving it down as far as it would go, revealing the second “4″ on the strip in the readout. Repeat for the 3 and the 2. Then, do the same with the 8 position of the “thousands” strip. The next 8 is alongside the upper half of the hundreds strip, so you can’t shove it all the way down; therefore, you shove that strip up and, at the top of the “shove,” you move your pen tip left and down, which “adds” a one to the number in the thousands register. In like manner, you add and carry until you have your result.
I must admit I found it fascinating at the time, just as I did when I discovered you could use two rulers as a rudimentary slide rule to add two numbers (as long as their total didn’t exceed 12).
Several years ago, Scientific American ran a story on the ongoing effort to build a full-scale replica of the original difference engine design. The metalwork was beautiful. I’ve always liked the sound of electromagnetic relays opening and closing to accomplish some computation or other, so I’m sure I’d enjoy an all-mechanical sound of “thought”!
I’m happy the video of the Curta included a look at its insides. Just the notion of having the number of teeth on a central gear correspond to the row’s vertical position on the gear is stimulating; the worm groove on the individual digit rods is thought-provoking, too.
It’s just a beautiful piece of work. I’d love to have one, but I understand the ones that are available tend to command very high prices.
Still, you never know. Maybe I’ll find one at an estate sale one day!