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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 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, especiall ... [...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 is one of the most extensive government laboratories in the UK and has a prestigious reputation for its role in setting and maintaining physical standards for British industry. Founded in 1900, it is one of the oldest metrology institutes in the world. Research and development work at NPL has contributed to the advancement of many disciplines of science, including the development early computers in the late 1940s and 1950s, construction of the first accurate atomic clock in 1955, and the invention and pioneering 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, west London. It is under the management of the Department for Business, Energy and Industrial ... [...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. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Electric
N.º UIC: 9094 110 1449-3 (Takargo Rail) The English Electric Company Limited (EE) was a British industrial manufacturer formed after the Armistice of 11 November 1918, armistice of World War I by amalgamating five businesses which, during the war, had been making munitions, armaments and aeroplanes. It initially specialised in industrial electric motors and transformers, railway locomotives and traction equipment, diesel motors and steam turbines. Its activities 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 Canberra and the Lightning. In 1960, English Electric Aircraft (40%) merged with Vickers (40%) and Bristol (20%) to form British Aircraft Corporation. In 1968 English Electric's operations were merged with GEC's, the combined business employing more than 250,000 people. Foundation Aiming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Electric DEUCE
The DEUCE (''Digital Electronic Universal Computing Engine'') was one of the earliest United Kingdom, 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 Automatic Computing Engine, ACE. Hardware description The DEUCE had 1450 thermionic valves, and used mercury (element), mercury delay-line memory, 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 indepen ... [...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 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. * 1.8 microseconds – the amount of time subtracted from the Earth's day as a result of the 2011 Japanese earthquake. * 2 m ... [...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. For many early computers, drum memory formed the main working memory of the computer. It was so common that these computers were often referred to as ''drum machines''. Some drums were also used as secondary storage as for example various IBM drum storage drives. 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 in turn were 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 considered the precu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Memory
Computer 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 volatile technologies (which lose data when off power) 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 arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round-off Error
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 of roundoff errors ... [...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 ''b' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Press
Academic Press (AP) is an academic book publisher founded in 1941. It was acquired by Harcourt, Brace & World in 1969. Reed Elsevier bought Harcourt in 2000, and 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 Well-known products include the ''Methods in Enzymology'' series and encyclopedias such as ''The International Encyclopedia of Public Health'' and the ''Encyclopedia of Neuroscience''. See also * Akademische Verlagsgesellschaft (AVG) — the German predecessor, founded in 1906 by Leo Jolowicz (1868–1940), the father of Walter Jolowicz Walter may refer to: People * Walter (name), both a surname and a given name * Little Walter, American blues harmonica player Marion Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating-point Arithmetic
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be represented as a base-ten floating-point number: 12.345 = \underbrace_\text \times \underbrace_\text\!\!\!\!\!\!^ In practice, most floating-point systems use base two, though base ten (decimal floating point) is also common. The term ''floating point'' refers to the fact that the number's radix point can "float" anywhere to the left, right, or between the significant digits of the number. This position is indicated by the exponent, so floating point can be considered a form of scientific notation. A floating-point system can be used to represent, with a fixed number of digits, numbers of very different orders of magnitude — such as the number of meters between galaxies or between protons in an atom. For this reason, floating-poin ... [...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 AFIPS, in particular by Saul Rosen, who was an editor until his death in 1991. 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 Gerardo Con Diaz with the University of California, Davis. See also * ''Technology and Culture'' * '' Information & Culture'' * Computer History Museum * Charles Babbage Institute References External links * Annals of the History of Compu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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