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Slob (KDF9)
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 lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octal Number
The octal numeral system, or oct for short, is the base-8 number system, and uses the 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 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 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 representation for decimal 74 is 1001010. Two zeroes can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 8080
The Intel 8080 (''"eighty-eighty"'') is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility.'' Electronic News'' was a weekly trade newspaper. The same advertisement appeared in the May 2, 1974 issue of ''Electronics'' magazine. The initial specified clock rate or frequency limit was 2 MHz, with common instructions using 4, 5, 7, 10, or 11 cycles. As a result, the processor is able to execute several hundred thousand instructions per second. Two faster variants, the 8080A-1 (sometimes referred to as the 8080B) and 8080A-2, became available later with clock frequency limits of 3.125 MHz and 2.63 MHz respectively. The 8080 needs two support chips to function in most applications: the i8224 clock generator/driver and the i8228 bus controller. It is implemented in N-type metal-oxide-semiconductor logic (NMOS) usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BYTE (magazine)
''Byte'' (stylized as ''BYTE'') was a microcomputer magazine, influential in the late 1970s and throughout the 1980s because of its wide-ranging editorial coverage. "''Byte'' magazine, the leading publication serving the homebrew market ..." ''Byte'' started in 1975, shortly after the first personal computers appeared as kits advertised in the back of electronics magazines. ''Byte'' was published monthly, with an initial yearly subscription price of $10. Whereas many magazines were dedicated to specific systems or the home or business users' perspective, ''Byte'' covered developments in the entire field of "small computers and software", and sometimes other computing fields such as supercomputers and high-reliability computing. Coverage was in-depth with much technical detail, rather than user-oriented. The company was purchased by McGraw-Hill in 1979, a watershed event that led to the rapid purchase of many of the early computer magazines by larger publishers. By this time t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Data Corporation
Control Data Corporation (CDC) was a mainframe and supercomputer firm. CDC was one of the nine major United States computer companies through most of the 1960s; the others were IBM, Burroughs Corporation, DEC, NCR, General Electric, Honeywell, RCA, and UNIVAC. CDC was well-known and highly regarded throughout the industry at the time. For most of the 1960s, Seymour Cray worked at CDC and developed a series of machines that were the fastest computers in the world by far, until Cray left the company to found Cray Research (CRI) in the 1970s. After several years of losses in the early 1980s, in 1988 CDC started to leave the computer manufacturing business and sell the related parts of the company, a process that was completed in 1992 with the creation of Control Data Systems, Inc. The remaining businesses of CDC currently operate as Ceridian. Background and origins: World War II–1957 During World War II the U.S. Navy had built up a classified team of engineers to build codeb ... [...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] |
Resurrection (magazine)
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] |
Offset Addressing (x86)
Offset or Off-Set may refer to: Arts, entertainment, and media * "Off-Set", a song by T.I. and Young Thug from the '' Furious 7: Original Motion Picture Soundtrack'' * ''Offset'' (EP), a 2018 EP by singer Kim Chung-ha * ''Offset'' (film), a 2006 film featuring Răzvan Vasilescu and Alexandra Maria Lara * Offset Software, a video game development company ** ''Project Offset'', working title of a first-person shooter video game by Offset Software People * Offset (rapper), a rapper and member of the American hip-hop trio Migos Science and engineering * Offset (botany), a separable part of a plant that can develop into a new, independent plant * Offset (computer science), the distance to (displacement of) an element within a data object * Offset (gears), the perpendicular distance between the axes of hypoid or offset-facing gears * Offset (geometry), see parallel curve * Offset (geophysics), the distance between a source and receiver of seismic or other geophysical readings * DC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squawk Code
A transponder (short for ''trans''mitter-res''ponder'' and sometimes abbreviated to XPDR, XPNDR, TPDR or TP) is an electronic device that produces a response when it receives a radio-frequency interrogation. Aircraft have transponders to assist in identifying them on air traffic control radar. Collision avoidance systems have been developed to use transponder transmissions as a means of detecting aircraft at risk of colliding with each other. Air traffic control units use the term "squawk" when they are assigning an aircraft a transponder code, ''e.g.'', "Squawk 7421". Squawk thus can be said to mean "select transponder code" or "squawking ''xxxx''" to mean "I have selected transponder code ''xxxx''". The transponder receives interrogation from the Secondary Surveillance Radar on 1030 MHz and replies on 1090 MHz. Secondary surveillance radar Secondary surveillance radar (SSR) is referred to as "secondary", to distinguish it from the "primary radar" that works by p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DEC RADIX 50
RADIX 50 or RAD50 (also referred to as RADIX50, RADIX-50 or RAD-50), is an uppercase-only character encoding created by Digital Equipment Corporation (DEC) for use on their DECSYSTEM-20, DECsystem, Programmed Data Processor, PDP, and VAX computers. RADIX 50's 40-character repertoire (050 in octal) can encode six characters plus four additional bits into one 36-bit computing, 36-bit machine word (computer architecture), word (PDP-6, PDP-10/DECsystem-10, DECSYSTEM-20), three characters plus two additional bits into one 18-bit computing, 18-bit word (PDP-9, PDP-15), or three characters into one 16-bit computing, 16-bit word (PDP-11, VAX). The actual encoding differs between the 36-bit and 16-bit systems. 36-bit systems In 36-bit DEC systems RADIX 50 was commonly used in symbol tables for assemblers or compilers which supported six-character symbol names from a 40-character alphabet. This left four bits to encode properties of the symbol. For its similarities to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM SQUOZE
SQUOZE (abbreviated as SQZ) is a memory-efficient representation of a combined source and relocatable object program file with a symbol table on punched cards which was introduced in 1958 with the SCAT assembler on the SHARE Operating System (SOS) for the IBM 709. A program in this format was called a ''SQUOZE deck''. It was also used on later machines including the IBM 7090 and 7094. Encoding In the ''SQUOZE encoding'', identifiers in the symbol table were represented in a 50-character alphabet, allowing a 36-bit machine word to represent six alphanumeric characters plus two flag bits, thus saving two bits per six characters, because the six bits normally allocated for each character could store up to 64 states rather than only the 50 states needed to represent the 50 letters of the alphabet, and 506 < 234. Using base 50 already saves a single bit every three characters, so it was used in two three-character chunks. The manual has a formula for encoding six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Conversion
Positional notation (or place-value notation, or positional numeral system) usually denotes the extension to any base of the Hindu–Arabic numeral system (or decimal system). More generally, a positional system is a numeral system in which the contribution of a digit to the value of a number is the value of the digit multiplied by a factor determined by the position of the digit. In early numeral systems, such as Roman numerals, a digit has only one value: I means one, X means ten and C a hundred (however, the value may be negated if placed before another digit). In modern positional systems, such as the decimal system, the position of the digit means that its value must be multiplied by some value: in 555, the three identical symbols represent five hundreds, five tens, and five units, respectively, due to their different positions in the digit string. The Babylonian numeral system, base 60, was the first positional system to be developed, and its influence is present today ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
