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A pinwheel calculator is a class of mechanical calculator described as early as 1685, and popular in the 19th and 20th century, calculating via wheels whose number of teeth were adjustable. These wheels, also called pinwheels, could be set by using a side lever which could expose anywhere from 0 to 9 teeth, and therefore when coupled to a ...
Despite the mechanical flaws of the stepped reckoner, it suggested possibilities to future calculator builders. The operating mechanism, invented by Leibniz, called the stepped cylinder or Leibniz wheel, was used in many calculating machines for 200 years, and into the 1970s with the Curta hand calculator.
In the position shown, the counting wheel meshes with three of the nine teeth of the Leibniz wheel. A Leibniz wheel or stepped drum is a cylinder with a set of teeth of incremental lengths which, when coupled to a counting wheel, can be used in the calculating engine of a class of mechanical calculators.
The gift of a Texas Instruments calculator opened a new world of math problems and secret codes in the years before smartphones. Calculator added up to fun for a math phobic kid in the 1970s ...
The Facit calculator, and one similar to it, are basically pinwheel machines, but the array of pinwheels moves sidewise, instead of the carriage. The pinwheels are biquinary; digits 1 through 4 cause the corresponding number of sliding pins to extend from the surface; digits 5 through 9 also extend a five-tooth sector as well as the same pins ...
Odhner thought of his machine in 1871 while repairing a Thomas' Arithmometer (which was the only mechanical calculator in production at the time) and decided to replace its heavy, bulky Leibniz cylinder by a lighter, smaller pinwheel disk. This is why the two machines share the same name but look completely different.
Was the first scientific calculator to fly in space in 1973. [5] HP-35 calculators were carried on the Skylab 3 and Skylab 4 flights, between July 1973 and February 1974. [6] Is the first pocket calculator with a numeric range that covered 200 decades (more precise 199, ±10 ±99). [5]
A partially disassembled Curta calculator, showing the digit slides and the stepped drum behind them Curta Type I calculator, top view Curta Type I calculator, bottom view. The Curta is a hand-held mechanical calculator designed by Curt Herzstark. [1] It is known for its extremely compact design: a small cylinder that fits in the palm of the hand.