Who invented Mark I?
Howard Aikin invented Mark I.
Howard Aiken, in full Howard Hathaway Aiken, (born March 9, 1900, Hoboken, New Jersey, U.S.—died March 14, 1973, St. Louis, Missouri), mathematician who invented the Harvard Mark I, forerunner of the modern electronic digital computer. Aiken did engineering work while he attended the University of Wisconsin, Madison.
Conceived by Harvard physics professor Howard Aiken, and designed and built by IBM, the Harvard Mark 1 is a room-sized, relay-based calculator. The machine had a fifty-foot long camshaft running the length of machine that synchronized the machine's thousands of component parts and used 3,500 relays.