 The IBM 7070 (1958), IBM 7090 (1959), and CDC 1604 (1960) were the first computers (as products for sale) based on transistors.Building on his silicon surface passivation method, Mohamed Atalla developed the metal–oxide–semiconductor (MOS) process in the late 1950s.He proposed the MOS process could be used to build the first working silicon field-effect transistor (FET), which he began working on building with the help of Dawon Kahng at Bell Labs.