Computing Developments in the Early 20th Century

Germany - Konrad Zuse During the 1930's and 40's in Germany, Konrad Zuse was developing a series of automatic calculating machines. They were almost entirely mechanical and had no stored program but they were contolled by punched tape (old film reels hand punched). The first compputer, the Z1, was entirely mechanical, including memory and logic gates, and so data transfer was difficult. The Z2 used relays for gates but was too unreliable for much use. The Z3, in 1941, used relays for memory as well, and had in total 2,600 of them. It was as fast as the Harvard Mark I, produced 2 years later, and could do 3,4 additions in a second. The Z4 was similar except Zuse reverted to a mechanical memory. In 1950, this was the only operational computer in Europe.