History of computing

   Mankind has learned to use the simplest counting devices for thousands of years ago. The most in demand was the need to determine the number of objects used in barter trade. One of the most simple solution was to use a weight equivalent changes the subject, that did not require an exact translation of its parts. For these purposes, use the simplest counterweight scales, which have thus become one of the first devices to quantify the mass.

   The equivalence principle has been widely used in the other, familiar to many, the simple counting devices Abacus or account. Number count the items corresponded to the number of dominoes moved this tool.

   A relatively complex device for the account can be clearly applied in the practice of many religions. A believer in the accounts as counting the grains on the number of beads spoken prayers, and when passing the full range of beads moved to a separate tail special grain-counters, refer to the number counted by the community.

   With the invention of gears appeared much more sophisticated devices perform calculations. Antikythera mechanism, discovered in the early XX century, which was found at the crash site of the ancient ship that sank around 65 BC. Oe. (Other sources say 80 or 87 BC. Oe.) Even able to simulate the motion of planets. Supposedly it was used for calendar calculations for religious purposes, the predictions of solar and lunar eclipses, determining the time of sowing and harvesting, and m / n. Calculations were performed by connecting over 30 bronze wheels and dials a number, to calculate the lunar phases used a differential transmission, the invention of which the researchers for a long time has not earlier than the XVI century. However, with the departure of the ancient skills of creating such devices have been forgotten, it took about one and a half thousand years that people have learned to re-create a similar complexity of mechanisms.

   In 1623 Wilhelm Schickard invented a "Count the Clock" - the first mechanical calculator, who could perform the four arithmetic operations. 'Calculating clock unit was called because, as in the present hours of operation mechanism was based on the sprockets and gears. Practical use of this invention found in the hands of another Schickard, philosopher and astronomer Johannes Kepler.

   Machines by Blaise Pascal ("Pascaline", 1642) and Gottfried Wilhelm Leibniz.

   Approximately in 1820, Charles Xavier Thomas created the first successful commercially available mechanical calculator - Adding machine Thomas, who could add, subtract, multiply and divide. Basically, it was based on the work of Leibniz. Mechanical calculators, believing decimal numbers were used until 1970.

   Leibniz also described the binary numeral system, the central ingredient of all modern computers. However, until 1940, many subsequent developments (including machines, Charles Babbage, and even the ENIAC in 1945) were based on more complex in implementation of the decimal system.

   John Napier noted that multiplication and division of numbers can be accomplished by adding and subtracting, respectively, the logarithms of these numbers. Real numbers can be represented by intervals of length on a ruler, and this formed the basis of calculations using the slide rule, which allowed to perform multiplication and division are much faster. Slide rules were used by several generations of engineers and other professionals, until the appearance of a pocket calculator. The engineers of the Apollo program sent a man to the moon, running on slide rules all the calculations, many of which demanded precision in the 3-4 mark.

   To produce the first logarithmic tables Napier needed to perform many multiplications, and at the same time, he developed sticks Napier.