IBM ASCC-Mark I photo album: close-up of sequence control unit to tape feeders
Date: 1944
Inventory Number: Lib.1964-053
Classification: Photograph
Subject:
Maker: International Business Machines Corporation (1911-present)
Maker: Cruft Laboratory, Harvard University (founded 1914)
Maker: Harvard Computation Laboratory (1944 - 1997)
Associate Name: Howard H. Aiken (1900 - 1973)
Associate Name: Clair D. Lake (1888 - 1958)
Associate Name: Benjamin M. Durfee (1897 - 1980)
Associate Name: Frank E. Hamilton (1898 - 1972)
Associate Name: Thomas J. Watson Sr. (1874 - 1956)
Associate Name: James W. Bryce (1880 - 1949)
Associate Name: Robert V. D. Campbell (born 1916)
Cultural Region:
Material:
Description:
This photograph is included among 117 photos in an album of 109 pages. The images portray the assembly of the IBM Automatic Sequence Controlled Calculator (Harvard Mark I) computer in the Cruft Laboratory of Harvard University's Physics Department and the ceremony in August 1944 in which it was dedicated.
Details of the people and activities in each photograph are given in separate entries from Lib.1964-001 to Lib.1964-109. Inventory record numbers with "a" and "b" attached refer to pairs of images originally glued to a single page of the album.
This photograph shows:
close-up from right to left: the sequence control unit that directs the Mark I's operations while it calculates the solution to a problem, three interpolators: tape feeding and value-selection mechanisms.
Details of the people and activities in each photograph are given in separate entries from Lib.1964-001 to Lib.1964-109. Inventory record numbers with "a" and "b" attached refer to pairs of images originally glued to a single page of the album.
This photograph shows:
close-up from right to left: the sequence control unit that directs the Mark I's operations while it calculates the solution to a problem, three interpolators: tape feeding and value-selection mechanisms.
In Collection(s)
Signedunsigned
Historical AttributesThe IBM Automatic Sequence Controlled Calculator (referred to as the IBM ASCC but better known as the Harvard Mark I ) was the first operating machine that could execute long computations automatically. Dr. Howard Aiken of Harvard University conceived of and led the project, which was built by IBM engineers in Endicott, New York, before being shipped to Cambridge, Massachusetts in February 1944. The principals at IBM included senior engineers Clair D. Lake, Benjamin Durfee, and Frank Hamilton, whom Aiken considered his co-inventors, plus James W. Bryce, IBM's chief engineer, and Thomas J. Watson, Sr., IBM's president.
The massive instrument had a steel frame 51 feet long and 8 feet high to hold the calculator, which consisted of an interlocking panel of small gears, counters, switches and control circuits, all only a few inches in depth. The Mark I used 500 miles of wire with 3 million connections, 3,500 multipole relays with 35,000 contacts, 2,225 counters, 1464 tenpole switches, and tiers of 72 adding machines, each with 23 significant numbers. It was the industry's largest electromechanical calculator.
How did it work? According to IBM, "The Mark I was a parallel synchronous calculator that could perform table lookup and the four fundamental arithmetic operations, in any specified sequence, on numbers up to 23 decimal digits in length. It had 60 switch registers for constants, 72 storage counters for intermediate results, a central multiplying-dividing unit, functional counters for computing transcendental functions, and three interpolators for reading functions punched into perforated tape. Numerical input was in the form of punched cards, paper tape or manually set switches. The output was printed by electric typewriters or punched into cards. Sequencing of operations was accomplished by a perforated tape."
The operator did not need to be a trained mathematician, but the problem to be solved needed to be programmed by a mathematician using a code book. The code holes were punched in a paper tape, which was then fed into the machine. Tapes coded with useful functions were added to a tape library for future use. The code book, which tried to include every known type of mathematical problem, was written by Howard H. Aiken, assisted by R. V. D. Campbell.
Howard Aiken first conceived of the machine to solve nonlinear equations when he was a graduate student in physics in 1937. He approached James Bryce at IBM that year. The project was formally approved by IBM's directors in 1939.
The machine was built and tested in IBM's Endicott, NY laboratory. It was shipped to Harvard on 31 January 1944, and arrived the next day. Durfee and D. R. Piatt supervised the assembly, testing, and modification of the machine during February 1944 in the Cruft Research Laboratory of Physics at Harvard University. By March 15th, the Mark I was in operational condition.
The computer was officially presented by IBM's president Thomas J. Watson to Harvard's president James B. Conant in a ceremony on 7 August 1944. By then, IBM had spent approximately $200,000 on the project and donated an additional $100,000 to Harvard to cover the Mark I's operating expenses.
At first, the computer was used exclusively by the U.S. Navy Bureau of Ships during World War II to run repetitive calculations for the production of mathematical tables. The work was supported by a technical staff, which included former IBM employees serving in the Navy. After the war, the Mark I operated at Harvard for about fifteen more years solving complex mathematica problems in a number of disciplines.
After its use was discontinued, a portion of the computer was preserved at Harvard as an exhibit. Another portion was sent to the Smithsonian Institution in Washington, D.C., and some of the ASCC's electromechanical counters were preserved in IBM's collection of historical computing devices. The Mark I at Harvard is now part of the Collection of Historical Scientific Instruments.
For a detailed description of the computer and its production history, please see the website maintained by the IBM corporate archives here.
This photo album in the Collection of Historical Scientific Instruments has photographs dating from 1944, which show the Mark I being assembled in the Cruft Laboratory of the Harvard Physics Department and take the story up through the August dedication ceremony. (See Lib.1964, the full scrapbook, and Lib.1964-001 through Lib.1964.109, for each individual page.)
The massive instrument had a steel frame 51 feet long and 8 feet high to hold the calculator, which consisted of an interlocking panel of small gears, counters, switches and control circuits, all only a few inches in depth. The Mark I used 500 miles of wire with 3 million connections, 3,500 multipole relays with 35,000 contacts, 2,225 counters, 1464 tenpole switches, and tiers of 72 adding machines, each with 23 significant numbers. It was the industry's largest electromechanical calculator.
How did it work? According to IBM, "The Mark I was a parallel synchronous calculator that could perform table lookup and the four fundamental arithmetic operations, in any specified sequence, on numbers up to 23 decimal digits in length. It had 60 switch registers for constants, 72 storage counters for intermediate results, a central multiplying-dividing unit, functional counters for computing transcendental functions, and three interpolators for reading functions punched into perforated tape. Numerical input was in the form of punched cards, paper tape or manually set switches. The output was printed by electric typewriters or punched into cards. Sequencing of operations was accomplished by a perforated tape."
The operator did not need to be a trained mathematician, but the problem to be solved needed to be programmed by a mathematician using a code book. The code holes were punched in a paper tape, which was then fed into the machine. Tapes coded with useful functions were added to a tape library for future use. The code book, which tried to include every known type of mathematical problem, was written by Howard H. Aiken, assisted by R. V. D. Campbell.
Howard Aiken first conceived of the machine to solve nonlinear equations when he was a graduate student in physics in 1937. He approached James Bryce at IBM that year. The project was formally approved by IBM's directors in 1939.
The machine was built and tested in IBM's Endicott, NY laboratory. It was shipped to Harvard on 31 January 1944, and arrived the next day. Durfee and D. R. Piatt supervised the assembly, testing, and modification of the machine during February 1944 in the Cruft Research Laboratory of Physics at Harvard University. By March 15th, the Mark I was in operational condition.
The computer was officially presented by IBM's president Thomas J. Watson to Harvard's president James B. Conant in a ceremony on 7 August 1944. By then, IBM had spent approximately $200,000 on the project and donated an additional $100,000 to Harvard to cover the Mark I's operating expenses.
At first, the computer was used exclusively by the U.S. Navy Bureau of Ships during World War II to run repetitive calculations for the production of mathematical tables. The work was supported by a technical staff, which included former IBM employees serving in the Navy. After the war, the Mark I operated at Harvard for about fifteen more years solving complex mathematica problems in a number of disciplines.
After its use was discontinued, a portion of the computer was preserved at Harvard as an exhibit. Another portion was sent to the Smithsonian Institution in Washington, D.C., and some of the ASCC's electromechanical counters were preserved in IBM's collection of historical computing devices. The Mark I at Harvard is now part of the Collection of Historical Scientific Instruments.
For a detailed description of the computer and its production history, please see the website maintained by the IBM corporate archives here.
This photo album in the Collection of Historical Scientific Instruments has photographs dating from 1944, which show the Mark I being assembled in the Cruft Laboratory of the Harvard Physics Department and take the story up through the August dedication ceremony. (See Lib.1964, the full scrapbook, and Lib.1964-001 through Lib.1964.109, for each individual page.)
Primary SourcesOnline exhibit about the ASCC produced by the IBM corporate archives.
