Z1 (computer)

The Z1 was a mechanical computer by Konrad Zuse in 1937. She worked as the first freely programmable calculator with binary numbers and had many computer architecture elements of the later model Z3, but was unreliable due to mechanical problems. Their successors, the Zuse Z3, 1941, Zuse Z4, 1945, were the first universal programmable computer.

Development and operation

Motivated by the idea of automating time-consuming but well formalized free-body calculations, planned and developed Zuse in 1935 a program-controlled calculating machine. The implementation by means of mechanical switching elements that are driven by a vacuum cleaner motor, it seemed more compact than with electromechanical relays. The machine worked in principle as designed, however, the mechanical switching elements entangled in the operating regularly, so that the Zuse Z1 did not reach sufficient reliability.


The Z1 is considered the forerunner of the modern computer, which is constructed in a similar form. She worked as a first computer with binary numbers and already owned a one- issue movement, an arithmetic unit, a memory unit and a program work, which was reading the programs of perforated film strip.


The Z1 was destroyed in the Second World War. Therefore, the Zuse KG in 1963 built it after. Also in this replica is entangled again the switching elements. A modified replica of the calculator, which was completed in 1989, stands at the German Technology Museum in Berlin.

More Zuse computer

  • Zuse Z2 (1939 )
  • Zuse Z3 (1941 )
  • Zuse Z4 (1942 )
  • Zuse Z11 (1955 )
  • Zuse Z22 (1955 )