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The IBM Automatic Sequence Controlled Calculator (ASCC), called Mark I by Harvard University’s staff,〔The machine’s name as actually displayed on the hardware itself is Aiken-IBM Automatic Sequence Controlled Calculator Mark I. An early photograph (Wilkes 1956:16 figure 1-7) displays the name as ''IBM Automatic Sequence Controlled Calculator''.〕 was a general purpose electro-mechanical computer that was used in the war effort during the last part of World War II. The original concept was presented to IBM by Howard Aiken in November 1937.〔Bernard Cohen, p. 53 (2000)〕 After a feasibility study by IBM’ engineers, Thomas Watson Sr. personally approved the project and its funding in February 1939. Howard Aiken had started to look for a company to design and build his calculator in early 1937. After two rejections,〔Bernard Cohen, p.39 (2000) It was first rejected by the Monroe Calculator Company and then by Harvard University.〕 he was shown a demonstration set that Charles Babbage’s son had given to Harvard university 70 years earlier. This led him to study Babbage and to add references of the Analytical Engine to his proposal; the resulting machine “brought Babbage’s principles of the Analytical Engine almost to full realization, while adding important new features.”〔(【引用サイトリンク】title=IBM’s ASCC introduction 2 )〕 The ASCC was developed and built by IBM at their Endicott plant and shipped to Harvard in February 1944. It began computations for the U.S. Navy Bureau of Ships in May and was officially presented to the university on August 24, 1944. One of the first programs to run on the Mark I was initiated on 29 March 1944〔Bernard Cohen, p.164 (2000)〕 by John von Neumann, who worked on the Manhattan project at the time, and needed to determine whether implosion was a viable choice to detonate the atomic bomb that would be used a year later. The Mark I also computed and printed mathematical tables, which was Charles Babbage’s initial goal for his analytical engine. The Mark I was officially retired, after 15 years of service, in 1959. ==Design and construction== The ASCC was built from switches, relays, rotating shafts, and clutches. It used 765,000 components and hundreds of miles of wire, comprising a volume of 51 feet (16 m) in length, eight feet (2.4 m) in height, and two feet (~61 cm) deep. It weighed about 10,000 pounds (4500 kg). The basic calculating units had to be synchronized mechanically, so they were run by a 50-foot (~15.5 m) shaft driven by a five-horsepower (4 kW) electric motor. From the IBM Archives: The Automatic Sequence Controlled Calculator (Harvard Mark I) was the first operating machine that could execute long computations automatically. A project conceived by Harvard University’s Dr. Howard Aiken, the Mark I was built by IBM engineers in Endicott, N.Y. A steel frame long and eight feet high held the calculator, which consisted of an interlocking panel of small gears, counters, switches and control circuits, all only a few inches in depth. The ASCC used of wire with three million connections, 3,500 multipole relays with 35,000 contacts, 2,225 counters, 1,464 tenpole switches and tiers of 72 adding machines, each with 23 significant numbers. It was the industry’s largest electromechanical calculator.〔(IBM Archives: FAQ / Products and Services )〕 The enclosure for the Mark I was designed by futuristic American industrial designer Norman Bel Geddes. Aiken considered the elaborate case to be a waste of resources, since computing power was in high demand during the war and the funds ($50,000 or more according to Grace Hopper) could have been used to build additional computer equipment.〔Computer Oral History Collection, 1969-1973, 1977 ''Grace Murray Hopper Interview, January 7, 1969'', Archives Center, National Museum of American History ()〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Harvard Mark I」の詳細全文を読む スポンサード リンク
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