History of computing technology

Theoretically, computing rests on positional number systems, exact rules (algorithms) and the theory of logic; practically, it rests on the technology of each age. In the 9th century Muhammad al-Khwarizmi described the positional system based on Hindu numerals and the rules of arithmetic; the word “algorithm” comes from his name. In logic, Aristotle, Leibniz and the English mathematician George Boole (1815–1864) made key contributions: in 1847 Boole created the algebra of logic, in which values are only 0 and 1. The history of computing is usually divided into four periods: before mechanical machines (fingers, tally sticks, the abacus, Napier’s rods – 1617, the slide rule), the mechanical period (Schickard – 1623, Pascal’s “Pascaline” – 1642, Charles Babbage’s designs from 1822), the electromechanical period (Zuse’s relay-based Z3 – 1941, Mark I – 1944) and the electronic period (ENIAC – 1946). Ada Lovelace wrote the first programs for Babbage’s machine. ENIAC had about 18,000 vacuum tubes and could perform 5,000 additions per second.