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Control Characters
In computing and telecommunication, a control character or non-printing character (NPC) is a code point (a number) in a character set, that does not represent a written symbol. They are used as in-band signaling to cause effects other than the addition of a symbol to the text. All other characters are mainly printing, printable, or graphic characters, except perhaps for the "space" character (see ASCII printable characters). History Procedural signs in Morse code are a form of control character. A form of control characters were introduced in the 1870 Baudot code: NUL and DEL. The 1901 Murray code added the carriage return (CR) and line feed (LF), and other versions of the Baudot code included other control characters. The bell character (BEL), which rang a bell to alert operators, was also an early teletype control character. Control characters have also been called "format effectors". In ASCII There were quite a few control characters defined (33 in ASCII, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C0 And C1 Control Codes
The C0 and C1 control code or control character sets define control codes for use in text by computer systems that use ASCII and derivatives of ASCII. The codes represent additional information about the text, such as the position of a cursor, an instruction to start a new line, or a message that the text has been received. C0 codes are the range 00 HEX–1FHEX and the default C0 set was originally defined in ISO 646 (ASCII). C1 codes are the range 80HEX–9FHEX and the default C1 set was originally defined in ECMA-48 (harmonized later with ISO 6429). The ISO/IEC 2022 system of specifying control and graphic characters allows other C0 and C1 sets to be available for specialized applications, but they are rarely used. C0 controls ASCII defined 32 control characters, plus a necessary extra character for the DEL character, 7FHEX or 01111111BIN (needed to punch out all the holes on a paper tape and erase it). This large number of codes was desirable at the time, as multi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, engineering, mathematical, technological and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology and software engineering. The term "computing" is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleprinter
A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Initially they were used in telegraphy, which developed in the late 1830s and 1840s as the first use of electrical engineering, though teleprinters were not used for telegraphy until 1887 at the earliest. The machines were adapted to provide a user interface to early mainframe computers and minicomputers, sending typed data to the computer and printing the response. Some models could also be used to create punched tape for data storage (either from typed input or from data received from a remote source) and to read back such tape for local printing or transmission. Teleprinters could use a variety of different communication media. These included a simple pair of wires; dedicated non-switched telephone circuits (leased lines); switched ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero-width Non-joiner
The zero-width non-joiner (ZWNJ) is a non-printing character used in the computerization of writing systems that make use of ligatures. When placed between two characters that would otherwise be connected into a ligature, a ZWNJ causes them to be printed in their final and initial forms, respectively. This is also an effect of a space character, but a ZWNJ is used when it is desirable to keep the characters closer together or to connect a word with its morpheme. The ZWNJ is encoded in Unicode as . Use of ZWNJ and unit separator for correct typography In certain languages, the ZWNJ is necessary for unambiguously specifying the correct typographic form of a character sequence. The ASCII control code unit separator was formerly used. The picture shows how the code looks when it is ''rendered'' correctly, and in every row the correct and incorrect pictures should be different. On a system which not configured to display the Unicode correctly, the correct display and the incor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, which is maintained by the Unicode Consortium, defines as of the current version (15.0) 149,186 characters covering 161 modern and historic scripts, as well as symbols, emoji (including in colors), and non-visual control and formatting codes. Unicode's success at unifying character sets has led to its widespread and predominant use in the internationalization and localization of computer software. The standard has been implemented in many recent technologies, including modern operating systems, XML, and most modern programming languages. The Unicode character repertoire is synchronized with ISO/IEC 10646, each being code-for-code identical with the other. ''The Unicode Standard'', however, includes more than just the base code. Along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 8859
ISO/IEC 8859 is a joint ISO and IEC series of standards for 8-bit character encodings. The series of standards consists of numbered parts, such as ISO/IEC 8859-1, ISO/IEC 8859-2, etc. There are 15 parts, excluding the abandoned ISO/IEC 8859-12. The ISO working group maintaining this series of standards has been disbanded. ISO/IEC 8859 parts 1, 2, 3, and 4 were originally Ecma International standard ECMA-94. Introduction While the bit patterns of the 95 printable ASCII characters are sufficient to exchange information in modern English, most other languages that use Latin alphabets need additional symbols not covered by ASCII. ISO/IEC 8859 sought to remedy this problem by utilizing the eighth bit in an 8-bit byte to allow positions for another 96 printable characters. Early encodings were limited to 7 bits because of restrictions of some data transmission protocols, and partially for historical reasons. However, more characters were needed than could fit in a single 8-bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extended ASCII
Extended ASCII is a repertoire of character encodings that include (most of) the original 96 ASCII character set, plus up to 128 additional characters. There is no formal definition of "extended ASCII", and even use of the term is sometimes criticized, because it can be mistakenly interpreted to mean that the American National Standards Institute (ANSI) had updated its standard to include more characters, or that the term identifies a single unambiguous encoding, neither of which is the case. The ISO standard ISO 8859 was the first international standard to formalise a (limited) expansion of the ASCII character set: of the many language variants it encoded, ISO 8859-1 ("ISO Latin 1")which supports most Western European languages is best known in the West. There are many other extended ASCII encodings (more than 220 DOS and Windows codepages). EBCDIC ("the other" major character code) likewise developed many extended variants (more than 186 EBCDIC codepages) over the decades. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delete Character
The delete control character (also called DEL or rubout) is the last character in the ASCII repertoire, with the code 127. It is supposed to do nothing and was designed to erase incorrect characters on paper tape. It is denoted as in caret notation and is in Unicode. Terminal emulators may produce DEL when key or or are typed. History This code was originally used to mark deleted characters on punched tape, since any character could be changed to all ones by punching holes everywhere. If a character was punched erroneously, punching out all seven bits caused this position to be ignored or deleted. In hexadecimal, this is 7F to rub out 7 bits ( FF to rubout 8 bits was used for 8-bit codes). This character could also be used as padding to slow down printing after newlines, though the all-zero NUL was more often used. The Teletype Model 33 provided a key labelled to punch this character (after the user backed up the tape using another button), and did not provide a key ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newline
Newline (frequently called line ending, end of line (EOL), next line (NEL) or line break) is a control character or sequence of control characters in character encoding specifications such as ASCII, EBCDIC, Unicode, etc. This character, or a sequence of characters, is used to signify the end of a line of text and the start of a new one. History In the mid-1800s, long before the advent of teleprinters and teletype machines, Morse code operators or telegraphists invented and used Morse code prosigns to encode white space text formatting in formal written text messages. In particular the Morse prosign (mnemonic reak ext) represented by the concatenation of literal textual Morse codes "B" and "T" characters sent without the normal inter-character spacing is used in Morse code to encode and indicate a ''new line'' or ''new section'' in a formal text message. Later, in the age of modern teleprinters, standardized character set control codes were developed to aid in white sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are , which severely limited its scope. All modern computer systems instead use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set. The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding. ASCII is one of the IEEE milestones. Overview ASCII was developed from telegraph code. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association's (ASA) (now the American National Standards I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ANSI X3
The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide. ANSI accredits standards that are developed by representatives of other standards organizations, government agencies, consumer groups, companies, and others. These standards ensure that the characteristics and performance of products are consistent, that people use the same definitions and terms, and that products are tested the same way. ANSI also accredits organizations that carry out product or personnel certification in accordance with requirements defined in international standards. The organization's headquarters are in Washington, D.C. ANSI's operations office is located in New York City. The ANSI annual operating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cursor (user Interface)
In human–computer interaction, a cursor is an indicator used to show the current position on a computer monitor or other display device that will respond to input from a text input or pointing device. The mouse cursor is also called a pointer, owing to its resemblance in usage to a pointing stick. Etymology ''Cursor'' is Latin for 'runner'. A cursor is a name given to the transparent slide engraved with a hairline used to mark a point on a slide rule. The term was then transferred to computers through analogy. On 14 November 1963, while attending a conference on computer graphics in Reno, Nevada, Douglas Engelbart of Augmentation Research Center (ARC) first expressed his thoughts to pursue his objective of developing both hardware and software computer technology to "augment" human intelligence by pondering how to adapt the underlying principles of the planimeter to inputting X- and Y-coordinate data, and envisioned something like the cursor of a mouse he initially called a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
