The electronic computer has now been used commercially for less than 25 years. It grew out of a search lasting centuries for a more accurate, faster way to perform calculations. .

             Primitive and ancient man used his fingers, shells, beads, sticks, and other objects to keep track of numbers and sums. The development of paper and writing instrumentsmade it easier to record data, but gave little aid in manipulating it.

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             Manual Devices:.

             A computer is sometimes defined as a system that mechanizes the processing of information. Even a manual device may fall under this definition if they are constructed in such a way that moving them by hand can produce the desired answer. Example:.

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             Abacus:.

             The abacus is the oldest-known mechanical computing aid. Its origin is uncertain. Many countries claim to have invented it. It was used in China as early as the sixth century B.C. and in the mediterranean areain ancient Greek and Roman times. It is still used in many parts of the world. .

             The abacus consists of beads strung on rows of wires suspended within a rectangular frame. A common form has a piece of wood dividing the beads, with five beads on one side, and two on the other side of the wood on each wire. .

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             Calculating Machines and their Inventors:.

             Through the centuries, several mathematical geniuses invented machinesto aid them in their calculations. The machines were never widely used and generally had no direct path to the later development of electronic computers. Example:.

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             Pascal:.

             Blaise Pascal (1623-1662) a French matematician, invented the first mechanical adding machine at age 19 in 1642. He became tired of adding long columns of figures while helping his father, who had been appointed administrator of Rouen by Cardenal Richelieu. His device had teen toothed wheels and many gears. Rotating wheels developed sums. A carry lever advanced the next wheel to the left one position when a sum exceeded 10.