Harvard’s first computer actually came from a line that started in the 1890s. Although we tend to think of them as modern inventions, in the closing decade of the 19th century Herman Hollerith, an employee of the U.S. Census Bureau, was inspired by a train conductor punching tickets to develop a device which could automatically read census information punched onto card. The idea of computer instructions via punch cards not only was the programming zeitgeist for near half a century, but led Hollerith to open up his own line of punch-card-based computers — a company he called International Business Machines. IBM.

On this day, August 7, in 1944 Harvard received the IBM-built Mark I, one of the first major punch-card computers in the world. In fully assembled form the computer took over a large room at the university: it was 51 feet long, 8 feet high, and stood out two feet from the wall.

Over three quarters of million different components went into the making of the Mark 1, and the basic calculating units were run by a 50-foot shaft powered by a five horsepower motor, the kind of power that went into turn-of-the-century automobiles. It was not very fast — additions or subtractions took a third of a second, but multiplication took six seconds, a division took 15.3 seconds, and a logarithm or a trigonometric function took over a minute — but it was fully programmable, meaning it did not require constant feeding of instructions.