Howard Aiken

Aiken took a physics doctorate at Harvard and grew tired of solving differential equations by hand. In 1937 he wrote a proposal for an automatic calculating machine, with Charles Babbage's Analytical Engine as the stated model — a fragment of Babbage's mechanism happened to sit in Harvard's own collection. IBM took the job and built the machine at Endicott under Clair Lake, Frank Hamilton and Benjamin Durfee, presenting it to Harvard in 1944.

At the unveiling Aiken described the machine as essentially his own. Thomas Watson, who had paid for it, was furious, and IBM built its later machines without academic partners — the SSEC of 1948 was the company's answer. Aiken got his credit and Harvard got its machine; IBM got the computer industry.

His designs kept instructions on paper tape and data in counters, strictly separated — the arrangement later named the Harvard architecture. He recruited Grace Hopper onto the Mark I programming group in 1944 and went on to build the Mark II, III and IV. The line about the United States needing only half a dozen computers is routinely attributed to him and cannot be sourced in that form.