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One of the great historical figures in the world of computing was the French mathematician and religious philosopher Blaise Pascal (1623-1662), the inventor of one of the earliest known mechanical calculators. |
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Pascal's father, Etienne, was a noble in the French court, a tax collector, and a mathematician. Pascal's mother died when Pascal was three years old. Five years later, the family moved to Paris and Etienne took over the education of the children. Pascal quickly showed a talent for mathematics. When he was only 17, he published a mathematical essay that earned the jealous envy of René Descartes, one of the founders of modern geometry. (Pascal's work actually had been completed before he was 16.) It was based on a theorem, which he called the hexagrammum mysticum, or mystic hexagram, that described the inscription of hexagons in conic sections (parabolas, hyperbolas, and ellipses). In addition to the theorem (now called Pascal's theorem), his essay included over 400 corollaries. |
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When Pascal was about 20, he constructed a mechanical calculator that performed addition and subtraction of 8-digit numbers. That calculator required the user to dial in the numbers to be added or subtracted; then the sum or difference appeared in a set of windows. It is believed that his motivation for building this machine was to aid his father in collecting taxes. The earliest version of the machine does indeed split the numbers into six decimal digits and two fractional digits, as would be used for calculating sums of money. The machine was hailed by his contemporaries as a great advance in mathematics, and Pascal built several more in different forms. It achieved such popularity that many fake, nonfunctional copies were built by others and displayed as novelties. Several of Pascal's calculators still exist in various museums. |
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Pascal's box, as it is called, was long believed to be the first mechanical calculator. However, in 1950, a letter from Wilhelm Shickard to Johannes Kepler written in 1624 |
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is a function call or function invocation. The computer temporarily puts the main function on hold and starts the Cube function running. When Cube has finished doing its work, the computer goes back to main and picks up where it left off. |
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Function Call (Function Invocation) The mechanism that transfers control to a function. |
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