 While the original ABC was dismantled and discarded in the 1940s a tribute was made to the late inventors, a replica of the ABC was made in 1997 where it took a team of researchers and engineers four years and $350,000 to build.The modern personal computer emerged in the 1970s, after several breakthroughs in semiconductor technology.These include the first working transistor by William Shockley, John Bardeen and Walter Brattain at Bell Labs in 1947, the silicon surface passivation process (via thermal oxidation) by Mohamed Atalla at Bell Labs in 1957, the monolithic integrated circuit chip by Robert Noyce at Fairchild Semiconductor in 1959, the metal-oxide-semiconductor field-effect transistor (MOSFET, or MOS transistor) by Mohamed Atalla and Dawon Kahng at Bell Labs in 1959, and the single-chip microprocessor (Intel 4004) by Federico Faggin, Marcian Hoff, Masatoshi Shima and Stanley Mazor at Intel in 1971.