En An Illustrated History of Computers nos cuentan la historia de las máquinas automáticas para hacer todo tipo de cálculos. Desde los primeros ábacos, hasta el nacimiento del primer ordenador personal, el Altair 8800, pasando por máquinas mecánicas, electrónicas, el nacimiento del microprocesador…
The abacus was an early aid for mathematical computations. Its only value is that it aids the memory of the human performing the calculation. A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator (multiplication and division are slower). The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. The abacus is still in use today, principally in the far east. A modern abacus consists of rings that slide over rods, but the older one pictured below dates from the time when pebbles were used for counting (the word «calculus» comes from the Latin word for pebble).
Vía: Microsiervos.