Schematic for the Computer System X-66744, Bell Telephone Laboratories
date: label: date made
content: 1947-03-20
name: label: maker
content: Bell Telephone Laboratories
notes: label: Description
content: 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.
label: Description
content: 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).
label: Description
content: References:
label: Description
content: Andrews, E.G. “Telephone Switching and the Early Bell Laboratories Computers.” The Bell System
label: Description
content: Technical Journal 42:2 March 1963): 341 – 353.
label: Description
content: Ceruzzi, Paul. Reckoners: The Prehistory of the Digital Computer from Relays to the Stored Program
label: Description
content: Concept, 1935-1945 (Westport, CT: Greenwood Press 1983).
label: Description
content: Kidwell, Peggy and Paul Ceruzzi. Landmarks in Digital Computing (Washington, D.C.: Smithsonian
label: Description
content: Institution Press, 1994).
label: Description
content: Millman, Sidney, Ed. A History of Engineering and Science in the Bell System: Communications Sciences
label: Description
content: 1925-1980 (AT&T Bell Laboratories, 1984).
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, New York City
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Computers & Business Machines
creditLine: label: Credit Line
content: Gift of New Mexico State University
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1983.3018.03.04
label: nonaccession number
content: 1983.3018
label: catalog number
content: 1983.3018.03.04
objectType: label: Object Name
content: blue-line print
physicalDescription: label: Physical Description
content: paper (overall material)
label: Measurements
content: overall (folded): 28 3/4 in x 27 3/4 in x 0 in; 73.025 cm x 70.485 cm x 0 cm