Schematic for the Computer System X-66744, Bell Telephone Laboratories

Description:

The computing collection contains several schematics of the computer system X-66744, created by Samuel B. Williams and George Stibitz at Bell Telephone Laboratories in New York City. Williams and Stibitz designed a series of six electromechanical relay computers between 1939 and 1949. The X-66744 was fifth in the series of computers, later called Models I through VI, which were deployed in defense efforts, including executing calculations for antiaircraft guns at federal agencies and military research hubs. This computer was one of two duplicate Model V versions created between 1946 and 1947. The Model V computers were sophisticated digital calculating machines that employed about 9,000 telephone relays for switching elements and paper tape for programming. They could perform multiple calculations using floating point numbers and contained a system for self-checking errors. The Model V represented the limits of what was possible with electromechanical relay technology for the time. Even though relays would fail intermittently, the self-checking system and ability to automatically switch to other calculations afforded the machine its reliable reputation and impressive track record for continuous around-the-clock operation.

In 1946, the x-66744 was delivered to the National Advisory Committee for Aeronautics (NACA) in Langley Field, Virginia. Then, in 1958 it was given to Texas Technical College, although according to a 1963 article in The Bell System Technical Journal, the machine suffered extensive damage in that shipment and its parts were salvaged for the other Model V computer that was in operation at Fort Bliss, Texas and later New Mexico State University at Las Cruces before portions of it were acquired by NMAH. The article erroneously mentions that the latter computer was transferred to the University of Arizona rather than New Mexico State University. See the Model V (or Model 5) Control Panel in the NMAH collection (1987.0821.01).

References:

Andrews, E.G. “Telephone Switching and the Early Bell Laboratories Computers.” The Bell System

Technical Journal 42:2 March 1963): 341 – 353.

Ceruzzi, Paul. Reckoners: The Prehistory of the Digital Computer from Relays to the Stored Program

Concept, 1935-1945 (Westport, CT: Greenwood Press 1983).

Kidwell, Peggy and Paul Ceruzzi. Landmarks in Digital Computing (Washington, D.C.: Smithsonian

Institution Press, 1994).

Millman, Sidney, Ed. A History of Engineering and Science in the Bell System: Communications Sciences

1925-1980 (AT&T Bell Laboratories, 1984).

Date Made: 1952-09-25

Maker: Bell Telephone Laboratories

Location: Currently not on view

Place Made: United States: New York, New York City

Subject: Mathematics

Subject:

See more items in: Medicine and Science: Mathematics, Computers & Business Machines

Exhibition:

Exhibition Location:

Credit Line: Gift of New Mexico State University

Data Source: National Museum of American History

Id Number: 1983.3018.10.06Nonaccession Number: 1983.3018Catalog Number: 1983.3018.10.06

Object Name: blueprint

Physical Description: paper (overall material)Measurements: overall (folded): 28 in x 37 1/4 in x 1/4 in; 71.12 cm x 94.615 cm x .635 cm

Guid: http://n2t.net/ark:/65665/ng49ca746b4-8335-704b-e053-15f76fa0b4fa

Record Id: nmah_1940585

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