Charles Babbage’s mechanical computers made with gears and shafts. 1820~1830s.
Vannevar Bush's differential analysers made with wheel and disc mechanisms. 1928–1931.
Claude Shannon's “A Symbolic Analysis of Relay and Switching Circuits.” 1937.
Researchers at the Bell Telephone Labs in Murray Hill, New Jersey,1947.
Jack Kilby of Texas Instruments, 1957.
								Bell labs, NYC
				
								Alan Turing and Claude Shannon