Howard Aiken

The Harvard Mark I, officially named the IBM Automatic Sequence Controlled Calculator, was one of the earliest large-scale electromechanical computers in the United States. Howard Aiken conceptualized the machine and spearheaded its development in collaboration with IBM engineers, with the project completed in 1944 and installed at Harvard University. It was used extensively by the U.S. Navy for wartime calculations during World War II.

Yes, Howard Aiken partnered with IBM to build the Harvard Mark I, with IBM providing engineering expertise and manufacturing resources under the direction of Thomas J. Watson Sr. The machine was physically built at IBM's facility in Endicott, New York, before being shipped to Harvard in 1944. After its completion, Aiken and IBM had a notable falling out over credit for the machine's design.

After the Mark I, Howard Aiken continued to oversee the development of subsequent Harvard Mark series computers, including the Mark II, Mark III, and Mark IV. These later machines gradually transitioned from electromechanical relay-based components to fully electronic architectures. He also founded the Harvard Computation Laboratory and became a leading academic figure in the emerging field of computer science.

The Harvard Mark I was programmed using paper tape sequences with 24 channels that encoded instructions for the machine's operations. It used a decimal number system rather than binary, and programs were fed into the machine via punched paper tape readers. Grace Hopper, who worked with Aiken at Harvard, was instrumental in developing programming methodology for the Mark series computers.