 It was not until 1949 that Zuse was able to resume work on the Z4.He would show the computer to the mathematician Eduard Stiefel of the Swiss Federal Institute of Technology Zurich ("Eidgenössische Technische Hochschule (ETH) Zürich") who then ordered one in 1950.In November 1949, Zuse KG was founded and that Z4 was delivered to ETH Zurich in July 1950, and proved very reliable.