IBM's first large-scale electronic computer
May 18, 2015
by Mark Ollig

Thomas J. Watson Jr., President of IBM, revealed to its shareholders on April 29, 1952 the company was constructing “the most advanced, most flexible high-speed computer in the world.”

What later became the IBM 701 Electronic Data Processing Machine was first known during its early development as the “Defense Calculator.”

It was named this because in 1950, at the start of the Korean War, IBM’s chairman, Thomas J. Watson Sr., had asked the US Government how his company could be of assistance.

The government’s reply to him was to ask IBM to build a large, scientific computer.

The computer would need to be capable of designing aircraft, assisting in nuclear development, engineering of armaments, performing calculations, and probably other details yours truly is not privy to.

IBM “put pencil to paper” and began designing this new computer in January 1951.

“We convinced ourselves that by taking a giant step toward this far-out high-performance machine, we and our customers would benefit in many ways,” said Jerrier Haddad, who worked for IBM.

Haddad was in charge of the technical and executive responsibilities for the 701 development and design program.

The IBM 701 was constructed in IBM’s Poughkeepsie, NY plant, where its parts were put together using production-line assembly techniques. It was the world’s first mass-produced computer.

This electronic digital computer had an input and output system, assorted memory devices, digital arithmetic-processing components, and what I viewed to be a well-organized, human-operator control center.

The 701 computer’s cabinet-bay wiring was neatly cabled using modular, pluggable ends.

It also had various physical devices for storing and retrieving information.

I had not heard of using a cathode ray tube (CRT) for storing binary information, until I read about the electrostatic data-storage system glass tubes used in the 701 computer.

Memory devices of the IBM 701 included 72 electrostatic data-storage “Williams-Kilburn tubes,” capable of holding 1,024 bits each. This total of 73,728 bits had the capacity of 2,048 words using 36-bits, when the logical wording address system used two 18-bit words.

These electrostatic tubes held the data/information as a “charge pattern.”

The 701 memory also used four magnetic-coated cylinder drums with a capacity of storing 81,920 digits.

The magnetic-coated cylinder drum memory could read and write at 8,000 digits per second.

In addition, four cabinet bays, each equipped with magnetic-tape drive units, held more than 8 million digits per individual tape-reel.

The magnetic-tape unit’s read and write speed was 12,500 digits per second.

In addition to vacuum tubes, several thousand germanium-diode electronic components were used inside the IBM 701 computer system.

Output information obtained from the IBM 701 could be sent to a paper printer at a rate of 150 lines per minute.

As far as processing capabilities, this circa 1951 IBM 701 computer performed exceptionally well for this time period.

The computer’s internal processing operations were performed using the binary system; yes, those bits and bytes made up of 1’s and 0’s.

Information from IBM’s 701 webpage states this computer could perform an average of 14,000 mathematical operations a second.

The IBM 701 was managed from an operator’s control center panel using buttons, keys, and switches for input instruction entry of the memory, accumulator, and multiplier-quotient registers.

It also had a lot of visual indicator activity lights.

Two IBM power frames, and an IBM power distribution unit, provided the electricity for the individual systems comprising the IBM 701 data processing computer.

April of 1952, an IBM 701 development machine computing model was assembled in an IBM office at Poughkeepsie, NY.

The individual equipment cabinets were neatly arranged inside the office; I noted the inter-machine cabinet cabling was smartly hidden from view.

Here is a photo of the IBM 701 in the Poughkeepsie office: http://tinyurl.com/mct2w67.

May 21, 1952 – 63 years ago this week – IBM branch managers were informed the Defense Calculator would now be referred to as the IBM Electronic Data Processing Machine.

There were 19 commercial IBM 701 Electronic Data Processing Machines manufactured.

The first shipped to IBM World Headquarters in New York, NY Dec. 20, 1952.

The University of California, in Los Alamos, NM, received the second IBM 701 computer March 23, 1953. It processed hydrodynamic calculations.

Some of the contractors and agencies receiving the IBM 701 included: Boeing, Lockheed, the US Navy, General Electric, and the National Security Agency – better known as the NSA.

Jan. 8, 1954, an IBM press release was written about Russian being translated into English using an “electronic brain.” This electronic brain could translate Russian to English onto an “automatic printer” at a speed of two-and-a-half lines per second.

This “electronic brain” was the IBM 701 computer.

The IBM website has an archival page with photos of the 701 computer, and its associated cabinet components at: http://tinyurl.com/lrms8u6.

The last IBM 701 computer (assembled from spare parts) was shipped to the US Weather Bureau in Washington, DC, Feb. 28, 1955.

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