A man standing by a control panel and in front of two cabinets electromechanical relays

Photographer unknown, 1984 – Source: Deutsches Museum

Konrad Zuse

Konrad Zuse's greatest achievement was the Z3, world's first functional, fully automatic, program-controlled and freely programmable computer. The design of the Z3 was, in principle, Turing-complete. The Z3 used 22-bit binary floating-point arithmetic and had a memory of 64 words. Program code was stored on punched film. The Z3 was completed in May 1941, but it was destroyed in a Berlin air raid in December 1943. A fully functioning replica was built in 1961 and it is located in Deutsches Museum, Berlin.