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Pilot ACE
The Pilot ACE (Automatic Computing Engine) 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. History Pilot ACE was built to be a cut-down version of Turing's full ACE design. After Turing left NPL (in part because he was disillusioned by the lack of progress on building the ACE), James H. Wilkinson took over the project. Donald Davies, Harry Huskey and Mike Woodger were involved with the design. The Pilot ACE ran its first program on 10 May 1950, and was demonstrated to the press in November 1950. Although originally intended as a prototype, it became clear that the machine was a potentially useful resource, esp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Physical Laboratory (United Kingdom)
The National Physical Laboratory (NPL) is the national measurement standards laboratory of the United Kingdom. It sets and maintains physical standards for British industry. Founded in 1900, the NPL is one of the oldest metrology institutes in the world. Research and development work at the laboratory has contributed to the advancement of many disciplines of science, including the development of early computers in the late 1940s and 1950s, construction of the first accurate atomic clock in 1955, and the invention and first implementation of packet switching in the 1960s, which is today one of the fundamental technologies of the Internet. The former heads of NPL include many individuals who were pillars of the British scientific establishment. NPL is based at Bushy Park in Teddington, southwest London. It is operated by NPL Management Ltd, a company owned by the Department for Science, Innovation and Technology, and is one of the most extensive government laboratories in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Huskey
Harry Douglas Huskey (January 19, 1916 – April 9, 2017) was an American computer design pioneer. Early life and career Huskey was born in Whittier, in the Smoky Mountains region of North Carolina and grew up in Idaho. He received his bachelor's degree in mathematics and physics at the University of Idaho. He was the first member of his family to attend college. He gained his Master's and then his PhD in 1943 from the Ohio State University on ''Contributions to the Problem of Geöcze''. Huskey taught mathematics to U.S. Navy students at the University of Pennsylvania and then worked part-time on the early ENIAC and EDVAC computers in 1945. This work represented his first formal introduction to computers, according to his obituary in ''The New York Times''. He visited the National Physical Laboratory (NPL) in the United Kingdom for a year and worked on the Pilot ACE computer with Alan Turing and others. He was also involved with the EDVAC and SEAC computer projects. Husk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Electric
The English Electric Company Limited (EE) was a British industrial manufacturer formed after World War I by amalgamating five businesses which, during the war, made munitions, armaments and aeroplanes. It initially specialised in industrial electric motors and transformers, locomotives and railway electric traction, traction equipment, diesel engine, diesel motors and steam turbines. Its products were later expanded to include consumer electronics, nuclear reactors, guided missiles, military aircraft and mainframe computers. Two English Electric aircraft designs became landmarks in British aeronautical engineering; the English Electric Canberra, Canberra and the English Electric Lightning, Lightning. In 1960, English Electric Aircraft (40%) merged with Vickers Armstrongs, Vickers (40%) and Bristol Aeroplane Company, Bristol (20%) to form British Aircraft Corporation. In 1968 English Electric's operations were merged with General Electric Company#Further expansion (1961–83), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Electric DEUCE
The DEUCE (''Digital Electronic Universal Computing Engine'') was one of the earliest British commercially available computers, built by English Electric from 1955. It was the production version of the Pilot ACE, itself a cut-down version of Alan Turing's ACE. Hardware description The DEUCE had 1450 thermionic valves, and used mercury delay lines for its main memory; each of the 12 delay lines could store 32 instructions or data words of 32 bits each. It adopted the then high 1 megahertz clock rate of the Pilot ACE. Input/output was via Hollerith 80-column punch-card equipment. The reader read cards at the rate of 200 per minute, while the card punch rate was 100 cards per minute. The DEUCE also had an 8192-word magnetic drum for main storage. To access any of the 256 tracks of 32 words, the drum had one group of 16 read and one group of 16 write heads, each group on independent moveable arms, each capable of moving to one of 16 positions. Access time was 15 mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsecond
A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is to one second, as one second is to approximately 11.57 days. A microsecond is equal to 1000 nanoseconds or of a millisecond. Because the next SI prefix is 1000 times larger, measurements of 10−5 and 10−4 seconds are typically expressed as tens or hundreds of microseconds. Examples * 1 microsecond (1 μs) – cycle time for frequency (1 MHz), the inverse unit. This corresponds to radio wavelength 300 m (AM medium wave band), as can be calculated by multiplying 1 μs by the speed of light (approximately ). * 1 microsecond – the length of time of a high-speed, commercial strobe light flash (see air-gap flash). * 1 microsecond – protein folding takes place on the order of microseconds (thus this is the speed of carbon-based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 memory as the main working memory of the computer. Some drums were also used as Auxiliary memory, secondary storage as for example various IBM_drum_storage, IBM drum storage drives and the UNIVAC FASTRAND series of drums. Drums were displaced as primary computer memory by magnetic core memory, which offered a better balance of size, speed, cost, reliability and potential for further improvements. Drums were then replaced by hard disk drives for secondary storage, which were both less expensive and offered denser storage. The manufacturing of drums ceased in the 1970s. Technical design A drum memory or drum storage unit contained a large metal cylinder, coated on the outside surface with a ferromagnetic recording material. It could be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Memory
Computer data storage or digital data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a storage hierarchy, which puts fast but expensive and small storage options close to the CPU and slower but less expensive and larger options further away. Generally, the fast technologies are referred to as "memory", while slower persistent technologies are referred to as "storage". Even the first computer designs, Charles Babbage's Analytical Engine and Percy Ludgate's Analytical Machine, clearly distinguished between processing and memory (Babbage stored numbers as rotations of gears, while Ludgate stored numbers as displacements of rods in shuttles). This distinction was extended in the Von Neumann architecture, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round-off Error
In computing, a roundoff error, also called rounding error, is the difference between the result produced by a given algorithm using exact arithmetic and the result produced by the same algorithm using finite-precision, rounded arithmetic. Rounding errors are due to inexactness in the representation of real numbers and the arithmetic operations done with them. This is a form of quantization error. When using approximation equations or algorithms, especially when using finitely many digits to represent real numbers (which in theory have infinitely many digits), one of the goals of numerical analysis is to estimate computation errors. Computation errors, also called numerical errors, include both truncation errors and roundoff errors. When a sequence of calculations with an input involving any roundoff error are made, errors may accumulate, sometimes dominating the calculation. In ill-conditioned problems, significant error may accumulate. In short, there are two major facets ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-point Arithmetic
In computing, fixed-point is a method of representing fractional (non-integer) numbers by storing a fixed number of digits of their fractional part. Dollar amounts, for example, are often stored with exactly two fractional digits, representing the cents (1/100 of dollar). More generally, the term may refer to representing fractional values as integer multiples of some fixed small unit, e.g. a fractional amount of hours as an integer multiple of ten-minute intervals. Fixed-point number representation is often contrasted to the more complicated and computationally demanding floating-point representation. In the fixed-point representation, the fraction is often expressed in the same number base as the integer part, but using negative powers of the base ''b''. The most common variants are decimal (base 10) and binary (base 2). The latter is commonly known also as binary scaling. Thus, if ''n'' fraction digits are stored, the value will always be an integer multiple of ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Press
Academic Press (AP) is an academic book publisher founded in 1941. It launched a British division in the 1950s. Academic Press was acquired by Harcourt, Brace & World in 1969. Reed Elsevier said in 2000 it would buy Harcourt, a deal completed the next year, after a regulatory review. Thus, Academic Press is now an imprint of Elsevier. Academic Press publishes reference books, serials and online products in the subject areas of: * Communications engineering * Economics * Environmental science * Finance * Food science and nutrition * Geophysics * Life sciences * Mathematics and statistics * Neuroscience * Physical sciences * Psychology Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feel ... Well-known products include the '' Methods in Enzymology'' series and encyclopedias such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating-point Arithmetic
In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a Sign (mathematics), signed sequence of a fixed number of digits in some Radix, base) multiplied by an integer power of that base. Numbers of this form are called floating-point numbers. For example, the number 2469/200 is a floating-point number in base ten with five digits: 2469/200 = 12.345 = \! \underbrace_\text \! \times \! \underbrace_\text\!\!\!\!\!\!\!\overbrace^ However, 7716/625 = 12.3456 is not a floating-point number in base ten with five digits—it needs six digits. The nearest floating-point number with only five digits is 12.346. And 1/3 = 0.3333… is not a floating-point number in base ten with any finite number of digits. In practice, most floating-point systems use Binary number, base two, though base ten (decimal floating point) is also common. Floating-point arithmetic operations, such as addition and division, approximate the correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE Annals Of The History Of Computing
The ''IEEE Annals of the History of Computing'' is a quarterly peer-reviewed academic journal published by the IEEE Computer Society. It covers the history of computing, computer science, and computer hardware. It was founded in 1979 by the American Federation of Information Processing Societies. The journal publishes scholarly articles, interviews, "think pieces", and memoirs by computer pioneers, and news and events in the field. It was established in July 1979 as ''Annals of the History of Computing'', with Bernard Galler as editor-in-chief. The journal became an IEEE publication in 1992, and was retitled to ''IEEE Annals of the History of Computing''. The 2020 impact factor was 0.741. The current editor in chief is Troy Astarte at Swansea University in Wales. See also * ''Technology and Culture'' * '' Information & Culture'' * Computer History Museum * Charles Babbage Institute The IT History Society (ITHS) is an organization that supports the history and scholarship o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
