The MOS integrated circuit, first proposed by Mohamed Atalla in 1960, led to the invention of the microprocessor. The silicon-gate MOS integrated circuit was developed by Federico Faggin at Fairchild Semiconductor in 1968. This led to the development of the first single-chip microprocessor, the Intel 4004. It began with the "Busicom Project" as Masatoshi Shima's three-chip CPU design in 1968, before Sharp's Tadashi Sasaki conceived of a single-chip CPU design, which he discussed with Busicom and Intel in 1968. The Intel 4004 was then developed as a single-chip microprocessor from 1969 to 1970, led by Intel's Federico Faggin, Marcian Hoff, and Stanley Mazor, and Busicom's Masatoshi Shima. The chip was mainly designed and realized by Faggin, with his silicon-gate MOS technology. The microprocessor led to the microcomputer revolution, with the development of the microcomputer, which would later be called the personal computer (PC).