The ACE was not built, but a smaller version, the Pilot ACE, was constructed at the National Physical Laboratory and became operational in 1950. A larger implementation of the ACE design was the MOSAIC computer which became operational in 1955. ACE also led to the Bendix G-15 and other computers.
Turing was sought by Womersley to work in the NPL on the ACE project; he accepted and began work on 1 October 1945 and by the end of the year he completed his outline of his 'Proposed electronic calculator', which was the first reasonably complete design of a stored-program computer and, apart from being on a much larger scale than the final working machine, anticipated the final realisation in most important respects.[4] However, because of the strict and long-lasting secrecy around the Bletchley Park work, he was prohibited (because of the Official Secrets Act) from explaining that he knew that his ideas could be implemented in an electronic device.[5] The better-known EDVAC design presented in the First Draft of a Report on the EDVAC (dated 30 June 1945), by John von Neumann, who knew of Turing's theoretical work, received much publicity, despite its incomplete nature and questionable lack of attribution of the sources of some of the ideas.
Turing's report on the ACE was written in late 1945 and included detailed logical circuit diagrams and a cost estimate of £11,200.[6] He felt that speed and size of memory were crucial and he proposed a high-speed memory of what would today be called 25 kilobytes, accessed at a speed of 1 MHz; he remarked that for the purposes required "the memory needs to be very large indeed by comparison with standards which prevail in most valve and relay work, and [so] it is necessary to look for some more economical form of storage", and that memory "appears to be the main limitation in the design of a calculator, i.e. if the storage problem can be solved all the rest is comparatively straightforward".[7] The ACE implemented subroutine calls,[8] whereas the EDVAC did not, and what also set the ACE apart from the EDVAC was the use of Abbreviated Computer Instructions,[5] an early form of programming language. Initially, it was planned that Tommy Flowers, the engineer at the Post Office Research Station at Dollis Hill in north London, who had been responsible for building the Colossus computers should build the ACE, but because of the secrecy around his wartime achievements and the pressure of post-war work, this was not possible.[citation needed]
Turing's colleagues at the NPL, not knowing about Colossus, thought that the engineering work to build a complete ACE was too ambitious, so the first version of the ACE that was built was the Pilot Model ACE, a smaller version of Turing's original design. Turing's assistant, Jim Wilkinson, worked on the logical design of the ACE and after Turing left for Cambridge in 1947, Wilkinson was appointed to lead the ACE group.[9] The Pilot ACE had fewer than 1000 thermionic valves (vacuum tubes) compared to about 18,000 in the ENIAC.[10] It used mercury delay lines for its main memory. Each of the 12 delay lines was 5feet (1.5m) long and propagated 32 instructions or data words of 32bits each. This ran its first program on 10 May 1950, at which time it was the fastest computer in the world; each of its delay lines had a throughput of 1Mbit/s.[11]
The first production versions of the Pilot ACE, the English Electric DEUCE, of which 31 were sold, were delivered in 1955.[12]
MOSAIC
A second implementation of the ACE design was the MOSAIC (Ministry of Supply Automatic Integrator and Computer). This was built by Allen Coombs and William Chandler of Dollis Hill who had worked with Tommy Flowers on building the ten Colossus computers. It was installed at the Radar Research and Development Establishment (RRDE) at Malvern, which later merged with the Telecommunications Research Establishment (TRE) to become the Royal Radar Establishment (RRE). It ran its first trial program in late 1952 or early 1953 and became operational in early 1955. MOSAIC contained 6,480 electronic valves and had an availability of about 75%. It occupied four rooms and was the largest of the early British computers. It was used to calculate aircraft trajectories from radar data. It continued operating until the early 1960s.[5][13][14]
Derivatives
The principles of the ACE design were used in the Bendix Corporation's G-15 computer.[15]:279 The engineering design was done by Harry Huskey who had spent 1947 in the ACE section at the NPL. He later contributed to the hardware designs for the EDVAC. The first G-15 ran in 1954[citation needed] and, as a relatively small single-user machine, some consider it to be the first personal computer.[16]
↑ Turing, Alan M. (1936), "On Computable Numbers, with an Application to the Entscheidungsproblem", Proceedings of the London Mathematical Society, 2, vol.42, no.1 (published 1937), pp.230–65, doi:10.1112/plms/s2-42.1.230, S2CID73712 (and Turing, Alan M. (1938), "On Computable Numbers, with an Application to the Entscheidungsproblem: A correction", Proceedings of the London Mathematical Society, 2, vol.43, no.6 (published 1937), pp.544–6, doi:10.1112/plms/s2-43.6.544 )
↑ Origins and development of the ACE project, B. J. Copeland, in Copeland (2005).
Copeland, Jack (2006), "Colossus and the Rise of the Modern Computer", in Copeland, B. Jack (ed.), Colossus: The Secrets of Bletchley Park's Codebreaking Computers, Oxford: Oxford University Press, pp.108–110, ISBN978-0-19-284055-4
Lavington, Simon H. (1980), Early British Computers: The Story of Vintage Computers and The People Who Built Them, Manchester University Press
Wilkinson, J. H. (1980), "Turing's Work at the National Physical Laboratory and the Construction of Pilot ACE, DEUCE and ACE", in Metropolis, Nicholas; Howlett, J.; Rota, G.-C. (eds.), A History of Computing in the Twentieth Century, New York: Academic Press
Yates, David M. (1997), Turing's Legacy: A History of Computing at the National Physical Laboratory, 1945-1995, London: Science Museum
Alan Mathison Turing was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. Turing was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer. He is widely considered to be the father of theoretical computer science and artificial intelligence.
Colossus was a set of computers developed by British codebreakers in the years 1943–1945 to help in the cryptanalysis of the Lorenz cipher. Colossus used thermionic valves to perform Boolean and counting operations. Colossus is thus regarded as the world's first programmable, electronic, digital computer, although it was programmed by switches and plugs and not by a stored program.
The Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal First Draft of a Report on the EDVAC, the machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service.
The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers.
Maxwell Herman Alexander Newman, FRS,, generally known as Max Newman, was a British mathematician and codebreaker. His work in World War II led to the construction of Colossus, the world's first operational, programmable electronic computer, and he established the Royal Society Computing Machine Laboratory at the University of Manchester, which produced the world's first working, stored-program electronic computer in 1948, the Manchester Baby.
A stored-program computer is a computer that stores program instructions in electronically or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechanisms.
The National Physical Laboratory (NPL) is the national measurement standards laboratory of the United Kingdom. It sets and maintains physical standards for British industry.
The von Neumann architecture—also known as the von Neumann model or Princeton architecture—is a computer architecture based on a 1945 description by John von Neumann, and by others, in the First Draft of a Report on the EDVAC. The document describes a design architecture for an electronic digital computer with these components:
The Manchester Baby, also called the Small-Scale Experimental Machine (SSEM), was the first electronic stored-program computer. It was built at the University of Manchester by Frederic C. Williams, Tom Kilburn, and Geoff Tootill, and ran its first program on 21 June 1948.
David John Wheeler was a computer scientist and professor of computer science at the University of Cambridge.
The Pilot ACE was one of the first computers built in the United Kingdom. Built at the National Physical Laboratory (NPL) in the early 1950s, it was also one of the earliest general-purpose, stored-program computers – joining other UK designs like the Manchester Mark 1 and EDSAC of the same era. It was a preliminary version of the full ACE, which was designed by Alan Turing, who left NPL before the construction was completed.
Thomas Harold Flowers MBE was an English engineer with the British General Post Office. During World War II, Flowers designed and built Colossus, the world's first programmable electronic computer, to help decipher encrypted German messages.
Harry Douglas Huskey was an American computer design pioneer.
Brian Jack Copeland is Professor of Philosophy at the University of Canterbury, Christchurch, New Zealand, and author of books on the computing pioneer Alan Turing.
Charles Eryl Wynn-Williams, was a Welsh physicist, noted for his research on electronic instrumentation for use in nuclear physics. His work on the scale-of-two counter contributed to the development of the modern computer.
The National Museum of Computing is a museum in the United Kingdom dedicated to collecting and restoring historic computer systems. The museum is based in rented premises at Bletchley Park in Milton Keynes, Buckinghamshire and opened in 2007. The building — Block H — was the first purpose-built computer centre in the world, hosting six Colossus computers by the end of World War II.
John Ronald Womersley was a British mathematician and computer scientist who made important contributions to computer development, and hemodynamics. Nowadays he is principally remembered for his contribution to blood flow, fluid dynamics and the eponymous Womersley number, a dimensionless parameter characterising unsteady flow.
Michael Woodger is a pioneering English computer scientist. He was influential in the development of the early Pilot ACE computer, working with Alan Turing, and later the design and documentation of programming languages such as ALGOL 60 and Ada. He was based at the National Physical Laboratory (NPL) located in Teddington, London, for most of his career.
The Turing Guide, written by Jack Copeland, Jonathan Bowen, Mark Sprevak, Robin Wilson, and others and published in 2017, is a book about the work and life of the British mathematician, philosopher, and early computer scientist, Alan Turing (1912–1954).
Turochamp is a chess program developed by Alan Turing and David Champernowne in 1948. It was created as part of research by the pair into computer science and machine learning. Turochamp is capable of playing an entire chess game against a human player at a low level of play by calculating all potential moves and all potential player moves in response, as well as some further moves it deems considerable. It then assigns point values to each game state, and selects the move resulting in the highest point value.
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