Zuse Z1
More info
- Creator
- Konrad Zuse
- Released
- 1938
- Type
- Mechanical binary computer
- Successor
- Z2, Z3
A fully mechanical binary computer cut from sheet metal in his parents' living room, which never ran for more than a few minutes at a stretch.
Konrad Zuse built it between 1936 and 1938 in the family flat on Methfesselstraße in Berlin, from some 20,000 parts he cut out of sheet metal with a fretsaw. The logic was therefore neither relays nor tubes but sliding metal bars, driven by an electric motor at roughly one hertz.
The architecture, by contrast, was startlingly modern: binary, 24-bit floating point, a 64-word memory kept separate from the arithmetic unit, and the program fed in from punched 35 mm film. Zuse had read remarkably little about what anyone else was doing, which is the usual explanation for why he chose binary while everyone else built in decimal.
The engineering tolerances were not there. The mechanical gates jammed and the machine could rarely be kept running through a complete program, which led to the Z2 with relays in the arithmetic unit and then to the Z3. The original was destroyed in the bombing of Berlin in December 1943. Zuse built a replica between 1986 and 1989 for the Deutsches Technikmuseum, and it jams too.