The SWAC (Standards Western Automatic Computer) was an early electronic digital

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

built in 1950 by the

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

National Bureau of Standards The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sc ...

(NBS) in Los Angeles, California. It was designed by Harry Huskey.

Overview

Like the SEAC which was built about the same time, the SWAC was a small-scale interim computer designed to be built quickly and put into operation while the NBS waited for more powerful computers to be completed (in particular, the RAYDAC by

Raytheon Raytheon is a business unit of RTX Corporation and is a major U.S. defense contractor and industrial corporation with manufacturing concentrations in weapons and military and commercial electronics. Founded in 1922, it merged in 2020 with Unite ...

). The machine used 2,300

vacuum tube A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

s. It had 256 words of

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...

, using

Williams tube The Williams tube, or the Williams–Kilburn tube named after inventors Frederic Calland Williams, Freddie Williams and Tom Kilburn, is an early form of computer memory. It was the first Random-access memory, random-access digital storage devi ...

s, with each word being 37 bits. It had only seven basic operations: add, subtract, and fixed-point multiply; comparison, data extraction, input and output. Several years later,

drum memory Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. Many early computers, called drum computers or drum machines, used drum ...

was added. When the SWAC was completed in August 1950, it was the fastest computer in the world. It continued to hold that status until the IAS computer was completed a year later. It could add two numbers and store the result in 64 microseconds. A similar multiplication took 384 microseconds. It was used by the NBS until 1954 when the Los Angeles office was closed, and then by

UCLA The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California, United States. Its academic roots were established in 1881 as a normal school then known as the southern branch of the C ...

until 1967 (with modifications). It was charged out there for $40 per hour. In January 1952, Raphael M. Robinson used the SWAC to discover five

Mersenne prime In mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form for some integer . They are named after Marin Mersenne, a French Minim friar, who studied them in the early 1 ...

s—the largest prime numbers known at the time, with 157, 183, 386, 664 and 687 digits. Additionally, the SWAC was vital in doing the intense calculation required for the X-ray analysis of the structure of

vitamin B12 Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. One of eight B vitamins, it serves as a vital cofactor (biochemistry), cofactor in DNA synthesis and both fatty acid metabolism, fatty acid and amino a ...

done by

Dorothy Hodgkin Dorothy Mary Crowfoot Hodgkin (née Crowfoot; 12 May 1910 – 29 July 1994) was a Nobel Prize-winning English chemist who advanced the technique of X-ray crystallography to determine the structure of biomolecules, which became essential for ...

.Hodgkin, D.C.; Pickworth, J.; Robertson, J.H; Trueblood, K.N.; Prosen, R.J; White, J.G. Nature. 1955. 176. 325. This was fundamental in Hodgkin receiving the

Nobel Prize in Chemistry The Nobel Prize in Chemistry () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outst ...

in 1964.

References

* Williams, Michael R. (1997). ''A History of Computing Technology''.

IEEE Computer Society IEEE Computer Society (commonly known as the Computer Society or CS) is a technical society of the Institute of Electrical and Electronics Engineers (IEEE) dedicated to computing, namely the major areas of hardware, software, standards and people ...

. * **

External links

IEEE Transcript: SWAC—Standards Western Automatic Computer: The Pioneer Day Session at NCC July 1978

Oral history interview with Alexandra Forsythe

Charles Babbage Institute The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...

, University of Minnesota. Alexandra Illmer Forsythe discusses the career of her husband, George Forsythe. At

he became involved with the National Bureau of Standards Western Automatic Computer (SWAC) until 1957, when the

closed its operation at UCLA. Also discusses his founding of the Stanford Computer Science Department.
Margaret R. Fox Papers, 1935-1976

, University of Minnesota. collection contains reports, including the original report on the ENIAC, UNIVAC, and many early in-house National Bureau of Standards (NBS) activity reports; memoranda on and histories of SEAC, SWAC, and DYSEAC; programming instructions for the UNIVAC, LARC, and MIDAC; patent evaluations and disclosures relevant to computers; system descriptions; speeches and articles written by Margaret Fox's colleagues; and correspondence of Samuel Alexander, Margaret Fox, and Samuel Williams.
MERSENNE AND FERMAT NUMBERS
by RAPHAEL M. ROBINSON. February 7, 1954. From "The Prime Pages". {{commonscat, position=left, SWAC (computer) One-of-a-kind computers Vacuum tube computers National Institute of Standards and Technology 1950s computers Computer-related introductions in 1950 1950 in California Science and technology in Greater Los Angeles

Overview

See also

References

Further reading

External links