A calculator started: The A tobacco
The first calculators were abacus, often constructed as a wooden frame with beads sliding on wires. The abacus was used for centuries before the adoption of the writing system of Arabic numerals, and even remain em ployees by merchants and clerks in China and other parts of the world do .
XVII Century
William Oughtred invented slide rule in 1622, being revealed by student Richard Delamain in 1630. Wilhelm Schickard built the first automatic calculator call ada "Calculator Clock" in 1623.
nineteenth century
Charles Babbage developed the concept further , opening the way to programmable computers, while the machine who built was too heavy to be operable.
The last quarter of the nineteenth century witnessed significant progress in mechanical calculators:
- Frank Baldwin in 1872 in the United States invented the calculator Gear, which was also independently developed two years later by WT enSuecia Odhner. Odhner model and similar to other companies sold several thousand units in 1870.
- E. Dorr Feltinventó in the United States comptómetro in 1884, the first machine operated for keys that allow adding and calculating (as opposed to previous designs that required to operate separate levers). In 1886 he joined with Robert Tarrant to establish it Felt & Tarrant Manufacturing Company, which produced thousands of comptómetros.
- In 1891 William S. Burroughs began to market his summing calculator printer. The Burroughs Corporation became one of the leading companies in the market for accounting machines and computers.
- Calculator Millionaire was made in 1893. It allowed direct multiplication by any digit.
In mid-1980 to currently
In March 2002 HP announced that it stopped making calculators, which was difficult to ccept by some fans of the company's products, taking particular range HP-48 base extremely loyal customers .
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