Z4 (computer)
The Z4 was the world's first commercial digital computer, designed by German engineer Konrad Zuse and built by his company Zuse Apparatebau between 1942 and 1945. The Z4 was Zuse's final target for the Z3 design, and like it, was an electromechanical, not an electronic machine.
Read more about Z4 (computer): Construction, Usage After WWII, Specifications