In 1936 German Konrad Zuse created the Z1 counting machine. The following years were devoted to improving the version for Z2, Z3 then Z4. The machines were intended only for military needs. The calculations were performed on numbers recorded in the binary system, i.e. a floating point representation. The machine was controlled by a program recorded on a perforated tape. Instead of mechanical parts, electromagnetic relays were used in the machines. The Z4 was used and operated until the late 1950s.

______________________________________________________________________________Konrad Zuse and his first computer of the world – TV report from 1958 (with subtitles)