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Herman Hollerith (February 29, 1860 – November 17, 1929) was a German-American statistician, inventor, and businessman who developed an electromechanical tabulating machine for punched cards to assist in summarizing information and, later, in accounting.
[7] [3] [8] Its addition time was 0.125 seconds (8 Hz) and the multiplication time was 0.750 seconds. This was a factor of 2.6 faster for addition and a factor of 8 faster for multiplication compared to the Mark I. It was the second machine (after the Bell Labs Relay Calculator) to have floating-point hardware. A unique feature of the Mark II ...
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.
Marchant XLA calculator, based on Friden's design. The Marchant Calculating Machine Company was founded in 1911 by Rodney and Alfred Marchant in Oakland, California. The company built mechanical, and then electromechanical calculators which had a reputation for reliability. First models were similar to the Odhner arithmometer.
(Facit-Odhner was a sub-sidiary of Facit) Facit calculating machine, 1954 Elof Ericsson (1887–1961), founder in 1922 of AB Åtvidabergs Industrier. Photo from 1937. Photo from 1937. Facit ( Facit AB ) was an industrial corporation and manufacturer of office products including furniture.
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 ...
The new machine, called the IBM Selective Sequence Electronic Calculator (SSEC), was ready to be installed by August 1947. [9] Watson called such machines calculators because computer then referred to humans employed to perform calculations and he wanted to convey the message that IBM's machines were not designed to replace people. Rather they ...
The two machines were essentially different in that Pascal's machine was designed primarily for addition and (with the use of complementary numbers) for subtraction. The adding machine in Schickard's design may have jammed in the unusual case of a carry being required across too many dials, but it could smoothly subtract by reversing the motion ...