Cooper was born on December 26, 1928, in Chicago, Illinois, the son of Arthur and Mary Cooper. He was a tinkerer from an early age, recalling in an interview with Seattle Times journalist Yukari Iwatani, “I'd been taking things apart and inventing things since I was a little kid …. I still have memories as a child trying to really understand how things work.” He graduated from the Illinois Institute of Technology in 1950, and from there enlisted in the U.S. Naval Reserves, serving on destroyers and a submarine. His first job was with the Teletype Corporation of Chicago, which made the units that provided remote communications services to media outlets.