In Switzerland, a user manual for this system was found, which was previously thought to be irrevocably lost. This will give researchers a deeper understanding of Z4, which is considered the oldest surviving digital computer.
The Z4 computer was built in 1945. It runs a program written on tape and needs a multi-person service team. Now the machine is in the German Museum in Munich.
Evelyn Boesch (ETH Zurich, Switzerland’s most prestigious university), an archivist from the Swiss Higher Technical School Zurich, found the manual among her father’s documents. Rene Boesch worked with the Swiss Association of Aviation Engineering, which was based at the University Aviation Institute. The Z4 computer was placed there in the early 1950s. Among Bosch’s documents were notes on mathematical problems solved with Z4, which were related to the development of the P-16 jet fighter.
The computer itself was created by the German engineer Konrad Zuse, who is probably also the author of the manual. The Z1, Z2 and Z3 computers created in 1938, 1940 and 1941 were destroyed during the 1944 bombing of Berlin. The Z5 system, created in 1945, survived. It was for this system that Zuse developed the world’s first high-level programming language, called Plankalkül.
Mathematician Eduard Stiefel later purchased Z4 for the ETH Zurich Institute of Applied Mathematics. In addition, the computer spent several years at the French-German Research Institute of Saint-Louis before being handed over to the German Museum in 1960.