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English Electric KDF9
KDF9 was an early British 48-bit computer designed and built by English Electric (which in 1968 was merged into International Computers Limited (ICL)). The first machine came into service in 1964 and the last of 29 machines was decommissioned in 1980 at the National Physical Laboratory. The KDF9 was designed for, and used almost entirely in, the mathematical and scientific processing fields in 1967, nine were in use in UK universities and technical colleges. The KDF8, developed in parallel, was aimed at commercial processing workloads. The KDF9 was an early example of a machine that directly supported multiprogramming, using offsets into its core memory to separate the programs into distinct virtual address spaces. Several operating systems were developed for the platform, including some that provided fully interactive use through PDP-8 machines acting as smart terminal servers. A number of compilers were available, notably both checkout and globally optimizing compilers for ... [...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] |
Zero Address Arithmetic
In computer science, computer engineering and programming language implementations, a stack machine is a computer processor or a virtual machine in which the primary interaction is moving short-lived temporary values to and from a push down stack. In the case of a hardware processor, a hardware stack is used. The use of a stack significantly reduces the required number of processor registers. Stack machines extend push-down automata with additional load/store operations or multiple stacks and hence are Turing-complete. Design Most or all stack machine instructions assume that operands will be from the stack, and results placed in the stack. The stack easily holds more than two inputs or more than one result, so a rich set of operations can be computed. In stack machine code (sometimes called p-code), instructions will frequently have only an opcode commanding an operation, with no additional fields identifying a constant, register or memory cell, known as a zero address fo ... [...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] |
Syllable (computing)
In computing, a syllable is a name for a platform-dependent unit of information storage. Depending on the target hardware, various bit widths (and sometimes internal groupings) are associated with it. Commonly used in the 1960s and 1970s, the term has mostly fallen into disuse in favour of terms like byte or word. Examples: * 3-bit syllables: some experimental CISC designs * 8-bit syllables: English Electric KDF9 (represented as syllabic octals and also called slob-octals or slobs in this context) and Burroughs large systems (see also: Burroughs B6x00-7x00 instruction set) * 12-bit syllables: NCR computers such as the NCR 315 (also called slabs in this context) and Burroughs large systems * 13-bit syllables: Saturn Launch Vehicle Digital Computer (LVDC) and Gemini Spacecraft On-Board Computer (OBC) See also * Byte * Catena (computing) * Instruction syllable * Nibble * Opcode * Opstring * Parcel (computing) * Syllable (in linguistics) * Word (computer architecture) In co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 7030 Stretch
The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. It was the fastest computer in the world from 1961 until the first CDC 6600 became operational in 1964."Designed by Seymour Cray, the CDC 6600 was almost three times faster than the next fastest machine of its day, the IBM 7030 Stretch." Originally designed to meet a requirement formulated by Edward Teller at Lawrence Livermore National Laboratory, the first example was delivered to Los Alamos National Laboratory in 1961, and a second customized version, the IBM 7950 Harvest, to the National Security Agency in 1962. The Stretch at the Atomic Weapons Research Establishment at Aldermaston, England was heavily used by researchers there and at AERE Harwell, but only after the development of the S2 Fortran Compiler which was the first to add dynamic arrays, and which was later ported to the Ferranti Atlas of Atlas Computer Laboratory at Chilton. The 7030 was much slower than expected and failed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as The Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The first bit is number 0, making the eighth bit number 7. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syllabic Octal
Syllabic octal and split octal are two similar notations for 8-bit and 16-bit octal numbers, respectively, used in some historical contexts. Syllabic octal ''Syllabic octal'' is an 8-bit octal number representation that was used by English Electric in conjunction with their KDF9 machine in the mid-1960s. Although the word 'byte' had been coined by the designers of the IBM 7030 Stretch for a group of eight bits, it was not yet well known, and English Electric used the word 'syllable' for what is now called a byte. Machine code programming used an unusual form of octal, known locally as 'bastardized octal'. It represented 8 bits with three octal digits but the first digit represented only the two most-significant bits, whilst the others the remaining two groups of three bits each. A more polite colloquial name was 'silly octal', derived from the official name which was ''syllabic octal'' (also known as 'slob-octal' or 'slob' notation,). This 8-bit notation was similar to the late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octal
The octal numeral system, or oct for short, is the radix, base-8 number system, and uses the Numerical digit, digits 0 to 7. This is to say that 10octal represents eight and 100octal represents sixty-four. However, English, like most languages, uses a Base 10, base-10 number system, hence a true octal system might use different vocabulary. In the decimal system, each place is a power of ten. For example: : \mathbf_ = \mathbf \times 10^1 + \mathbf \times 10^0 In the octal system, each place is a power of eight. For example: : \mathbf_8 = \mathbf \times 8^2 + \mathbf \times 8^1 + \mathbf \times 8^0 By performing the calculation above in the familiar decimal system, we see why 112 in octal is equal to 64+8+2=74 in decimal. Octal numerals can be easily converted from Binary numeral system, binary representations (similar to a quaternary numeral system) by grouping consecutive binary digits into groups of three (starting from the right, for integers). For example, the binary repr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dhrystone
Dhrystone is a synthetic computing benchmark program developed in 1984 by Reinhold P. Weicker intended to be representative of system (integer) programming. The Dhrystone grew to become representative of general processor ( CPU) performance. The name "Dhrystone" is a pun on a different benchmark algorithm called Whetstone (pun explained: w''h''et-stone = wet-stone , d''h''ry-stone = dry-stone), which emphasizes floating point performance. With Dhrystone, Weicker gathered meta-data from a broad range of software, including programs written in FORTRAN, PL/1, SAL, ALGOL 68, and Pascal. He then characterized these programs in terms of various common constructs: procedure calls, pointer indirections, assignments, etc. From this he wrote the Dhrystone benchmark to correspond to a representative mix. Dhrystone was published in Ada, with the C version for Unix developed by Rick Richardson ("version 1.1") greatly contributing to its popularity. Dhrystone vs. Whetstone The Dhrysto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whetstone (benchmark)
The Whetstone benchmark is a synthetic Benchmark (computing), benchmark for evaluating the performance of computers. It was first written in Algol 60 in 1972 at the Technical Support Unit of the Department of Trade and Industry (later part of the Central Computer and Telecommunications Agency) in the United Kingdom. It was derived from statistics on program behaviour gathered on the KDF9 computer at NPL National Physical Laboratory, UK, National Physical Laboratory, using a modified version of its Whetstone ALGOL 60 compiler. The workload on the machine was represented as a set of frequencies of execution of the 124 instructions of the Whetstone Code. The Whetstone Compiler was built at the Atomic Power Division of the English Electric Company in Whetstone, Leicestershire, England, hence its name. Dr. B.A. Wichman at NPL produced a set of 42 simple ALGOL 60 statements, which in a suitable combination matched the execution statistics. To make a more practical benchmark Harold Curnow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Conservation Society
The Computer Conservation Society (CCS) is a British organisation, founded in 1989. It is under the joint umbrella of the British Computer Society (BCS), the London Science Museum and the Manchester Museum of Science and Industry. Overview The CCS is interested in the history of computing in general and the conservation and preservation of early British historical computers in particular. The society runs a series of monthly public lectures between September and May each year in both London and Manchester. The events are detailed on the society's website. The CCS publishes a quarterly journal, ''Resurrection''. The society celebrated its 25th anniversary in 2014. Dr Doron Swade, formerly the curator of the computing collection at the London Science Museum, was a founding committee member and is the current chair of the society. David Morriss, Rachel Burnett, and Roger Johnson are previous chairs, also all previous presidents of the BCS. Projects The society organises ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas Computer
The Atlas Computer was one of the world's first supercomputers, in use from 1962 (when it was claimed to be the most powerful computer in the world) to 1972. Atlas' capacity promoted the saying that when it went offline, half of the United Kingdom's computer capacity was lost. It is notable for being the first machine with virtual memory (at that time referred to as 'one-level store') using paging techniques; this approach quickly spread, and is now ubiquitous. Atlas was a second-generation computer, using discrete germanium transistors. Atlas was created in a joint development effort among the University of Manchester, Ferranti International plc and the Plessey Co., plc. Two other Atlas machines were built: one for British Petroleum and the University of London, and one for the Atlas Computer Laboratory at Chilton near Oxford. A derivative system was built by Ferranti for Cambridge University. Called the Titan, or Atlas 2, it had a different memory organisation and ran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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