This was IBM’s Harvard Mark 1, the first electromechanical computer, a “monster” of almost five tons


IBM is one of the pioneering computer manufacturing houses. Founded in 1911 by Charles Flint in New York, it was born under the name of Computing Tabulating Recording Corporation, assuming the name of International Business Machines in 1924. Twenty years later, he would give the Harvard University the first electromechanical computer, the Mark 1.

It was a monster almost five tons, with a height of 2.4 meters and a length of almost 16 meters, with a utility that today would be a source of laughter: the simple and straightforward calculation of operations.

The first electromechanical computer it used electromagnetic signals to move its parts, operating with relays and programming itself with switches.

But to arrive at each result, IBM’s Harvard Mark 1 took 3 to 5 seconds, and the sequence of calculations could not be changed.

had 760 thousand wheels and 800 kilometers of wiring, 3,300 relays and more than 175 thousand connections.

The Story of IBM’s Harvard Mark 1

Howard H. Aiken conceived of the machine in the 1930s. This Harvard-educated theoretical physicist initially proposed the digital calculator to the faculty of his alma mater’s Physics Department, then taking his idea to the Monroe Calculating Machine Company and finally to IBM.

Chief Engineer Clair D. Lake led the project, assisted by Benjamin Durfee and Frank Hamilton. Although they began in 1939, the vicissitudes of World War II, which the United States entered in 1941, affected their development.

IBM's Harvard Mark I, the first electromechanical computer, had 760,000 wheels and 800 kilometers of wiring, 3,300 relays, and more than 175,000 connections.

Finally, the machine was shipped to Harvard in February 1944, assembling and formally presenting itself on August 7 of that year.

How much did it cost to make the first electromechanical computer? 200 thousand dollars. IBM also donated an extra $100,000 to cover the operating costs of the Harvard Mark 1.

According to Harvard University, Mark 1 “mainly helped the Navy by computing tables for the design of equipment such as torpedoes and underwater detection systems. Other branches of the military sought his help in calculating the design of surveillance camera lenses, radars and implosion devices for the atomic bomb in the Manhattan Project”.

This is how the first electromechanical computer worked

IBM explains on its portal how the Harvard Mark 1 worked. Its two main functions were to perform table lookups and the four fundamental arithmetic operations, in any specified sequence, with numbers up to 23 decimal digits in length.

the computer had with 60 switching registers for constants, 72 storage counters for intermediate results, a central multiplication and division unit, functional counters for calculating transcendental functions and three interpolators to read work perforated on punch tape.

“Numerical input,” the company notes, “was in the form of punch cards, paper tape, or manually set switches. The output was printed on electric typewriters or punched onto cards.

Today we can find calculators up to the size of watches. Before, that was unthinkable: for it there was the monstrous IBM Harvard Mark 1.

Leave A Reply