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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 (with values 0..3), whilst the others the remaining two groups of three bits (with values 0..7) 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octal Number
Octal (base 8) is a numeral system with eight as the base. 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 be added at the left: , corresponding to the octal digits , yielding the octal representation 112. Usage In China The eight bagua or trigrams of the I Ching correspond to octal digits: * 0 = ☷, 1 = ☳, 2 = ☵, 3 = ☱, * 4 = ☶, 5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel 8080
The Intel 8080 is Intel's second 8-bit computing, 8-bit microprocessor. Introduced in April 1974, the 8080 was an enhanced successor to the earlier Intel 8008 microprocessor, although without binary compatibility.'' Electronic News'' was a weekly trade newspaper. The same advertisement appeared in the :File:Intel 8080 Advertisement May 1974.jpg, May 2, 1974, issue of ''Electronics'' magazine. Originally intended for use in Embedded system, embedded systems such as calculators, cash registers, computer terminals, and industrial robots, its robust performance soon led to adoption in a broader range of systems, ultimately helping to launch the microcomputer industry. Several key design choices contributed to the 8080’s success. Its 40‑pin package simplified interfacing compared to the 8008’s 18‑pin design, enabling a more efficient data bus. The transition to NMOS logic, NMOS technology provided faster transistor speeds than the 8008's PMOS logic, PMOS while also simplifyin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Data Corporation
Control Data Corporation (CDC) was a mainframe and supercomputer company that in the 1960s was one of the nine major U.S. computer companies, which group included IBM, the Burroughs Corporation, and the Digital Equipment Corporation (DEC), the NCR Corporation (NCR), General Electric, Honeywell, RCA, and UNIVAC. For most of the 1960s, the strength of CDC was the work of the electrical engineer Seymour Cray who developed a series of fast computers, then considered the fastest computing machines in the world; in the 1970s, Cray left the Control Data Corporation and founded Cray Research (CRI) to design and make supercomputers. In 1988, after much financial loss, the Control Data Corporation began withdrawing from making computers and sold the affiliated companies of CDC; in 1992, CDC established Control Data Systems, Inc. The remaining affiliate companies of CDC currently do business as the software company Dayforce. Background: World War II – 1957 During World War II the Un ... [...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 organise ... [...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 * D ... [...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 (ATC) 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 ... [...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, 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 machine word (PDP-6, PDP-10/DECsystem-10, DECSYSTEM-20), three characters plus two additional bits into one 18-bit word (PDP-9, PDP-15), or three characters into one 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 SQUOZE character encoding scheme used in IBM's SHARE Operating System for representing object code symbols, DEC's variant ... [...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. SQUOZE deck A SQUOZE deck contains an encoded binary form of the original assembly language code; SQUOZE decks are converted to absolute machine code and stored in memory by a loader program. Identifier name character 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Conversion
Positional notation, also known as place-value notation, positional numeral system, or simply place value, 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 values may be modified when combined). 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
