"The head of the department, Mr. Munich said, 'See, Herzstark, I understand you've been working on a new thing, a small calculating machine. Do you know, I can give you a tip. We will allow you to make and draw everything. If it is really worth something, then we will give it to the Führer as a present after we win the war. Then, surely, you will... See more

"I started to concentrate on possible solutions and at first, naturally, didn't get any further," said Hertzstark. "Later, I had an idea that I should look at everything backwards. I thought to myself, I'll pretend that I have already invented everything. What does this kind of machine really have to look like, so that someone could use it? It... See more

Then along came Curt Herzstark, a young man who in the 1920s regularly traveled through the former Austrian Empire selling mechanical calculators to banks and other businesses. It was on these travels that he heard the same complaints from his customers.

What's worse was that inside the device each digit of a number was set on a separate register with its own mechanism that had to be repeated up to eight to 10 times. Then to compound the problem, subtraction meant duplicating all these in reverse, plus a special mechanism to handle carrying the number when necessary. No wonder a handheld calculator... See more

By 1938, Hertzstark had applied for patents for his new design and had made a couple of prototypes of the basic mechanism out of Bakelite plastic to demonstrate the principle. Unfortunately, that's as far as he got because in March 1938 the Anschluss took place and Nazi Germany's Wehrmacht marched over the border to annex Austria.

The inside of a... See more

the Curta hit the world market in 1949 selling for US$125 through mail order and in a handful of specialty shops. It was a lot of money in those days, but the Curta was still a hit with engineers, traveling accountants, pilots, and even rally drivers. In the end, 150,000 of them were built in two models over the course of 20 years. It also gained a... See more

Some relief from tedious manual number crunching came in the 17th century with the invention of logarithms followed by mechanical aids like the slide rule and the first adding machines. Unfortunately, they weren't that much of a help. Slide rules couldn't handle numbers to more than two or three decimal places and, for centuries, calculators were... See more

But he did have the plans and the prototypes of the Curta, which was a true marvel of design and construction – as much like a watch movement or the mechanism of a fine camera as it was a calculator. But could he find backers to manufacture it?

In 1945, that was a difficult question. At first glance, the Curta looks as much like a calculator as a... See more

And all this without batteries and to 8 to eleven places.