Harvard Mark I
In the 1930s, the scientific landscape lacked tools capable of solving highly complex mathematical problems. Howard Aiken, a budding physicist at Harvard, set out to fill this gap. During 1937, he sketched the plans for a calculator that would process entire rows instead of the columns favored by machines of the era. He envisioned a machine capable of juggling positive and negative numbers, handling transcendent functions, and automatically chaining calculations.
After a rocky path with various manufacturers, Aiken finally convinced IBM. The company christened the project the Automatic Sequence Controlled Calculator (ASCC). March 1939 marked the signing of an agreement whereby IBM would build the machine as a gift to Harvard, which would provide facilities and personnel. Construction began two months later in IBM’s laboratories in Endicott, New York. Aiken worked closely with engineer Clair D. Lake to bring this ambitious project to fruition.
The prototype emerged in January 1943 and successfully passed its initial tests. Transported disassembled to Harvard, it took up residence in the basement of the Physics Research Laboratory. In spring 1944, as it became operational, its use was diverted toward the war effort. Robert Campbell took command of a U.S. Navy team that included Grace Murray Hopper and Richard Bloch. Aiken, a reserve officer, joined active service in 1941 to work on naval mines before taking command of the Mark I.
On August 7, 1944, an official ceremony brought together James Bryant Conant, president of Harvard, and Thomas J. Watson Sr., president of IBM. The event turned sour following a press release drafted under Aiken’s influence that attributed all credit for the invention to himself, almost entirely erasing IBM’s contribution. Watson, furious, threatened to boycott the ceremony. Aiken had to back down and acknowledge the role played by Lake, Hamilton, and Durfee in creating this machine.
The mechanical behemoth impressed with its dimensions: 15.5 meters long, 2.4 meters high, with a mass of 4.5 tons. Its interior housed electromagnetic relays, rotary decimal counters, and perforated tapes for instruction input. Data entered via punched cards and exited through modified electric typewriters. Slow compared to future electronic marvels, the Mark I compensated with exemplary reliability. It ran without interruption, day and night, producing a continuous flow of results.
Beyond the technical achievement, this machine embodied the feasibility of large-scale automatic calculators. These machines could now follow a sequence of operations from beginning to end without human intervention. The worldwide media coverage generated by its prowess swept away the last doubts about the future of such machines in the scientific sphere. The Harvard Mark I symbolizes the transition between the era of manual calculation and the dawn of modern computing.
Aiken did not stop at this first success. He developed a series of four increasingly sophisticated calculators. A visionary, he understood that these new machines called for a new generation of mathematicians capable of programming them. He persuaded Harvard to create a specific curriculum, first at the master’s level and then at the doctoral level, in this nascent discipline that was computer science. The first tenured professor in this still-virgin field, he initiated what appears to have been the first academic program of its kind in the world. His teaching shaped pioneers such as Gerrit Blaauw, Frederick Brooks Jr., Kenneth Iverson, and Anthony Oettinger.