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Six-bit Character Code
A six-bit character code is a character encoding designed for use on computers with word lengths a multiple of 6. Six bits can only encode 64 distinct characters, so these codes generally include only the upper-case letters, the numerals, some punctuation characters, and sometimes control characters. The 7-track magnetic tape format was developed to store data in such codes, along with an additional parity bit. Types of six-bit codes An early six-bit binary code was used for Braille, the reading system for the blind that was developed in the 1820s. The earliest computers dealt with numeric data only, and made no provision for character data. Six-bit BCD, with several variants, was used by IBM on early computers such as the IBM 702 in 1953 and the IBM 704 in 1954. Six-bit encodings were replaced by the 8-bit EBCDIC code starting in 1964, when System/360 standardized on 8-bit bytes. There are some variants of this type of code (see below). Six-bit character codes generally succ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character Encoding
Character encoding is the process of assigning numbers to graphical character (computing), characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using computers. The numerical values that make up a character encoding are known as code points and collectively comprise a code space or a code page. Early character encodings that originated with optical or electrical telegraphy and in early computers could only represent a subset of the characters used in written languages, sometimes restricted to Letter case, upper case letters, Numeral system, numerals and some punctuation only. Over time, character encodings capable of representing more characters were created, such as ASCII, the ISO/IEC 8859 encodings, various computer vendor encodings, and Unicode encodings such as UTF-8 and UTF-16. The Popularity of text encodings, most popular character encoding on the World Wide Web is UTF-8, which is used in 98.2% of surve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Telegraph Alphabet
The Baudot code () is an early character encoding for telegraphy invented by Émile Baudot in the 1870s. It was the predecessor to the International Telegraph Alphabet No. 2 (ITA2), the most common teleprinter code in use before ASCII. Each Character (symbol), character in the alphabet is represented by a series of five bits, sent over a communication channel such as a telegraph wire or a radio signal by asynchronous serial communication. The symbol rate measurement is known as baud, and is derived from the same name. History Baudot code (ITA1) In the below table, Columns I, II, III, IV, and V show the code; the Let. and Fig. columns show the letters and numbers for the Continental and UK versions; and the sort keys present the table in the order: alphabetical, Gray and UK Baudot developed his first multiplexed telegraph in 1872 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Equipment Corporation
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until he was forced to resign in 1992, after the company had gone into precipitous decline. The company produced many different product lines over its history. It is best known for the work in the minicomputer market starting in the early 1960s. The company produced a series of machines known as the Programmed Data Processor, PDP line, with the PDP-8 and PDP-11 being among the most successful minis in history. Their success was only surpassed by another DEC product, the late-1970s VAX "supermini" systems that were designed to replace the PDP-11. Although a number of competitors had successfully competed with Digital through the 1970s, the VAX cemented the company's place as a leading vendor in the computer space. As microcomputers improved in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO/IEC 7811
ISO/IEC 7811 ''Identification cards — Recording technique'' is a set of nine (7811-1 to 7811-9) standards describing the recording technique on identification cards. It comprises: "Part 1" '' Embossing'' "Part 2" ''Magnetic stripe — Low coercivity Coercivity, also called the magnetic coercivity, coercive field or coercive force, is a measure of the ability of a ferromagnetic material to withstand an external magnetic field without becoming Magnetization, demagnetized. Coercivity is usual ...'' "Part 3" ''Location of embossed characters on ID-1 cards''Part 3 is already withdrawn and revised by Part 1. "Part 4" ''Location of read-only magnetic tracks — Tracks 1 and 2''Part 4 is already withdrawn and revised by Part 2. ''Location of read-write magnetic track — Track 3''Part 5 is already withdrawn and revised by Part 2. ''Magnetic stripe — High coercivity'' ''Magnetic stripe — High coercivity, high density''Allows capacity 10 times that of a card conforming to Par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Stripe Card
The term digital card can refer to a physical item, such as a memory card on a camera, or, increasingly since 2017, to the digital content hosted as a virtual card or cloud card, as a digital virtual representation of a physical card. They share a common purpose: identity management, credit card, debit card or driver's license. A non-physical digital card, unlike a #Magnetic stripe card, magnetic stripe card, can Emulator, emulate (imitate) any kind of card. A smartphone or smartwatch can store content from the card issuer; discount offers and news updates can be transmitted wirelessly, via Internet. These virtual cards are used in very high volumes by the mass transit sector, replacing paper-based tickets and the earlier magnetic strip cards. History Magnetic recording on steel tape and wire was invented by Valdemar Poulsen in Denmark around 1900 for recording audio. In the 1950s, magnetic recording of digital computer data on plastic tape coated with iron oxide was invente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 700/7000 Series
The IBM 700/7000 series is a series of large-scale (Mainframe computer, mainframe) computer systems that were made by IBM through the 1950s and early 1960s. The series includes several different, incompatible processor architectures. The 700s use vacuum-tube logic and were made obsolete by the introduction of the transistor computer, transistorized 7000s. The 7000s, in turn, were eventually replaced with IBM System/360, System/360, which was announced in 1964. However the 360/65, the first 360 powerful enough to replace 7000s, did not become available until November 1965. Early problems with OS/360 and the high cost of converting software kept many 7000s in service for years afterward. Architectures The IBM 700/7000 series has six completely different ways of storing data and instructions: *First scientific (36/18-bit words): IBM 701, 701 (Defense Calculator) *Later scientific (36-bit words, hardware Floating-point arithmetic, floating-point): IBM 704, 704, IBM 709, 709, IBM 70 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1400 Series
The IBM 1400 series are second-generation (transistor) mid-range business decimal computers that IBM marketed in the early 1960s. The computers were offered to replace tabulating machines like the IBM 407. The 1400-series machines stored information in magnetic cores as variable-length character strings separated on the left by a special bit, called a "wordmark," and on the right by a "record mark." Arithmetic was performed digit-by-digit. Input and output support included punched card, magnetic tape, and high-speed line printers. Disk storage Disc or disk may refer to: * Disk (mathematics) In geometry, a disk (Spelling of disc, also spelled disc) is the region in a plane (geometry), plane bounded by a circle. A disk is said to be ''closed'' if it contains the circle that constitut ... was also available. Many members of the series could be used as independent systems, as extensions to IBM punched-card equipment, or as auxiliary equipment to other computer systems. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1620
The IBM 1620 was a model of scientific minicomputer produced by IBM. It was announced on October 21, 1959, and was then marketed as an inexpensive scientific computer. After a total production of about two thousand machines, it was withdrawn on November 19, 1970. Modified versions of the 1620 were used as the CPU of the IBM 1710 and IBM 1720 Industrial Process Control Systems (making it the first digital computer considered reliable enough for real-time computing, real-time process control of factory equipment). Being variable word length (computer hardware), variable-word-length decimal, as opposed to fixed-word-length pure binary, made it an especially attractive first computer to learn on and hundreds of thousands of students had their first experiences with a computer on the IBM 1620. Core memory cycle times were 20 microseconds for the (earlier) #Model I, Model I, 10 microseconds for the #Model II, Model II (about a thousand times slower than typical computer main memory in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Code
A binary code represents plain text, text, instruction set, computer processor instructions, or any other data using a two-symbol system. The two-symbol system used is often "0" and "1" from the binary number, binary number system. The binary code assigns a pattern of binary digits, also known as bits, to each character, instruction, etc. For example, a binary string (computer science), string of eight bits (which is also called a byte) can represent any of 256 possible values and can, therefore, represent a wide variety of different items. In computing and telecommunications, binary codes are used for various methods of encoding data, such as character strings, into bit strings. Those methods may use fixed-width or variable-length code, variable-width strings. In a fixed-width binary code, each letter, digit, or other character is represented by a bit string of the same length; that bit string, interpreted as a binary number, is usually displayed in code tables in octal, decimal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punched Card Code
A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widely used for data processing, the control of automated machines, and computing. Early applications included controlling weaving looms and recording census data. Punched cards were widely used in the 20th century, where unit record machines, organized into data processing systems, used punched cards for data input, data output, and data storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and data. Punched cards were used for decades before being replaced by magnetic storage and terminals. Their influence persists in cultural references, standardized data layouts, and computing conventions such as 80-cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BCD (6-bit)
BCD (''binary-coded decimal''), also called alphanumeric BCD, alphameric BCD, BCD Interchange Code, or BCDIC, is a family of representations of numerals, uppercase Latin letters, and some special and control characters as six-bit character codes. Unlike later encodings such as ASCII, BCD codes were not standardized. Different computer manufacturers, and even different product lines from the same manufacturer, often had their own variants, and sometimes included unique characters. Other six-bit encodings with completely different mappings, such as some FIELDATA variants or Transcode, are sometimes incorrectly termed BCD. Many variants of BCD encode the characters '0' through '9' as the corresponding binary values. History Technically, ''binary-coded decimal'' describes the encoding of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four. With the introduction of the '' IBM card'' in 1928, IBM created a code capable of representing al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitespace Character
A whitespace character is a character data element that represents white space when text is rendered for display by a computer. For example, a ''space'' character (, ASCII 32) represents blank space such as a word divider in a Western script. A printable character results in output when rendered, but a whitespace character does not. Instead, whitespace characters define the layout of text to a limited degree, interrupting the normal sequence of rendering characters next to each other. The output of subsequent characters is typically shifted to the right (or to the left for right-to-left script) or to the start of the next line. The effect of multiple sequential whitespace characters is cumulative such that the next printable character is rendered at a location based on the accumulated effect of preceding whitespace characters. The origin of the term ''whitespace'' is rooted in the common practice of rendering text on white paper. Normally, a whitespace character is ''not' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
