Konrad Zuse built a working programmable computer in his parents' Berlin flat
Bored by the endless hand calculations of aircraft design, a young Berlin engineer started building a calculating machine in his parents' living room. Konrad Zuse's Z3, switched on in May 1941 using discarded telephone relays, is counted as the first working programmable computer, though nobody proved it was Turing complete until 1998.
Zuse was born in Berlin on 22 June 1910 and grew up in Braunsberg, in East Prussia, and later Hoyerswerda. At the technical university in Berlin he found engineering and architecture dull before settling on civil engineering, graduating in 1935. A spell designing adverts for Ford was followed by work at the Henschel aircraft factory, where repetitive calculations convinced him a machine should do them.
From 1936 he built the Z1 at home: a binary, floating-point mechanical calculator of roughly 30,000 metal parts that read instructions from punched 35 mm film. It never ran reliably, and a British air raid destroyed it along with its blueprints on 30 January 1944. In 1937 he filed patents foreshadowing the von Neumann design, and he rejected his friend Helmut Schreyer's suggestion of vacuum tubes as a crazy idea. Working almost entirely in isolation, he moved on to relays for the Z2 and then the Z3, a 22-bit machine with loops but no conditional jumps, unveiled on 12 May 1941.
After 1939 the Nazi state funded him. His S1 and S2 machines calculated wing corrections for radio-guided flying bombs, and the S2, with a built-in analog-to-digital converter, is regarded as the first process-control computer. Zuse never joined the party but is not known to have voiced qualms about the war work. Meanwhile, finding machine code too cumbersome, he spent 1943 to 1945 devising Plankalkül, the earliest programming language pitched above machine level; it went unpublished in full until 1972 and was first implemented in 1975.
Bombing in 1945 drove him to the Allgäu, where post-war poverty halted hardware work. An IBM option on his patents helped fund a new firm, and his Z4, delivered to ETH Zurich in July 1950, became the first commercial computer and inspired Switzerland's first. In 1969 his book Calculating Space proposed that the universe itself might be a computation. He rebuilt the Z1 in his late seventies, painted under the name Kuno See, and died on 18 December 1995.
Source: Konrad Zuse
