|
β
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 HEXβ1FHEX and the default C0 set was originally defined in ISO 646 (ASCII). C1 codes are the range 80HEXβ9FHEX 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 defines 32 control characters, plus the DEL character. This large number of codes was desirable at the time, as multi-byte controls would require implementation of a state machine in the terminal, which was very difficult with contemporary electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control characters a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example, the first 128 code points of Unicode are the same as ASCII. ASCII encodes each code-point as a value from 0 to 127 storable as a seven-bit integer. Ninety-five code-points are printable, including digits ''0'' to ''9'', lowercase letters ''a'' to ''z'', uppercase letters ''A'' to ''Z'', and commonly used punctuation symbols. For example, the letter is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with ; most of which are now obsolete. The control cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Character
In computing and telecommunications, a control character or non-printing character (NPC) is a code point in a character encoding, character set that does not represent a written Character (computing), character or 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 ''graphic characters'', also known as ''printing characters'' (or ''printable characters''), except perhaps for "space (punctuation), space" characters. In the ASCII standard there are 33 control characters, such as code 7, , which rings a terminal bell. History Prosigns for Morse code, 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 op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tab Stop
A tab stop on a typewriter is a location where the carriage movement is halted by an adjustable end stop. Tab stops are set manually, and pressing the tab key causes the carriage to go to the next tab stop. In text editors on a computer, the same concept is implemented simplistically with automatic, fixed tab stops. Modern word processors generalize this concept by offering tab stops that have an alignment attribute and cause the text to be automatically aligned at left, at right or center of the tab stop itself. Such tab stops are paragraph-specific properties and can be moved to a different location in any moment, or even removed. Sometimes, placeholders in code snippets are also called "tab stops" because the user can cycle through them by pressing the tab key. Types of tab stops A tab stop is a horizontal position which is set for placing and aligning text on a page. There are at least five kinds of tab stops in general usage in word processing or in Microsoft Word. ;Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizontal Tab
The tab key (abbreviation of tabulator key or tabular key) on a keyboard is used to advance the cursor to the next tab stop. History The word ''tab'' derives from the word ''tabulate'', which means "to arrange data in a tabular, or table, form". When a person wanted to type a table (of numbers or text) on a typewriter, there was a lot of time-consuming and repetitive use of the space bar and backspace key. To simplify this, a horizontal bar was placed in the mechanism called the tabulator rack. Pressing the tab key would advance the carriage to the next tabulator stop. The original tabulator stops were adjustable clips that could be arranged by the user on the tabulator rack. Fredric Hillard filed a patent application for such a mechanism in 1900. The tab mechanism came into its own as a rapid and consistent way of uniformly indenting the first line of each paragraph. Often a first tab stop at 5 or 6 characters was used for this, far larger than the indentation used whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backspace
Backspace (, β«) is the keyboard key that in typewriters originally pushed the carriage one position backwards, and in modern computer systems typically moves the display cursor one position backwards,The meaning of "backwards" depends on the direction of the text, and could get complicated in text involving several Bidirectional text, bidirectional categories. deletes the character at that position, and shifts back any text after"after" here implies on the same logical line of text that position by one character. Nomenclature Although the term "backspace" is the traditional name of the key which steps the carriage back and/orin some correcting typewriters it did both deletes the previous character, typically to the left of the cursor, the actual key may be labeled in a variety of ways, for example ''delete'', ''erase'', or with a left pointing arrow. A dedicated symbol for "backspace" exists as Miscellaneous Technical#Block, U+232B β« but its use as a keyboard label is not univ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Character
A bell character (sometimes bell code) is a device control code originally sent to ring a small electromechanical bell on tickers and other teleprinters and teletypewriters to alert operators at the other end of the line, often of an incoming message. Though tickers punched the bell codes into their tapes, printers generally do not print a character when the bell code is received. Bell codes are usually represented by the label "BEL". They have been used since 1870 (initially in the Baudot code). To maintain backward compatibility, video display terminals (VDTs) that replaced teletypewriters included speakers or buzzers to perform the same function, as did the personal computers that followed. Modern terminal emulators often integrate the warnings to the desktop environment (e.g., the macOS Terminal will play the system warning sound) and also often offer a silent ''visual bell'' feature that flashes the terminal window briefly. Representations In ASCII the bell characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Perl originally was not capitalized and the name was changed to being capitalized by the time Perl 4 was released. The latest release is Perl 5, first released in 1994. From 2000 to October 2019 a sixth version of Perl was in development; the sixth version's name was changed to Raku. Both languages continue to be developed independently by different development teams which liberally borrow ideas from each other. Perl borrows features from other programming languages including C, sh, AWK, and sed. It provides text processing facilities without the arbitrary data-length limits of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emoji
An emoji ( ; plural emoji or emojis; , ) is a pictogram, logogram, ideogram, or smiley embedded in text and used in electronic messages and web pages. The primary function of modern emoji is to fill in emotional cues otherwise missing from typed conversation as well as to replace words as part of a logographic system. Emoji exist in various genres, including facial expressions, expressions, activity, food and drinks, celebrations, flags, objects, symbols, places, types of weather, animals, and nature. Originally meaning pictograph, the word ''emoji'' comes from Japanese + ; the resemblance to the English words ''emotion'' and ''emoticon'' is False cognate, purely coincidental. The first emoji sets were created by Japanese portable electronic device companies in the late 1980s and the 1990s. Emoji became increasingly popular worldwide in the 2010s after Unicode began encoding emoji into the Unicode Standard. They are now considered to be a large part of popular culture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acknowledge Character
In data networking, telecommunications, and computer buses, an acknowledgement (ACK) is a signal that is passed between communicating processes, computers, or devices to signify acknowledgment, or receipt of message, as part of a communications protocol. Correspondingly a negative-acknowledgement (NAK or NACK) is a signal that is sent to reject a previously received message or to indicate some kind of error. Acknowledgments and negative acknowledgments inform a sender of the receiver's state so that it can adjust its own state accordingly. Acknowledgment signal types The ASCII code point for ACK is 0x06 (binary 0000 0110). By convention a receiving device sends an ACK to indicate it successfully received a message. ASCII also provides a NAK code point (0x15, binary 0001 0101) which can be used to indicate the receiving device cannot, or will not, comply with the message. Unicode provides visible symbols for these ASCII characters, U+2406 (β) and U+2415 (β). ACK and NAK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enquiry Character
In computer communications, enquiry is a transmission-control character that requests a response from the receiving station with which a connection has been set up. It represents a signal intended to trigger a response at the receiving end, to see whether it is still present. The response, an answer-back code to the terminal that transmitted the WRU (who are you) signal, may include station identification, the type of equipment in service, and the status of the remote station. Some teleprinters had a "programmable" drum, which could hold a 20- or 22-character message. The message was encoded on the drum by breaking tabs off the drum. This sequence could be transmitted upon receipt of an enquiry signal, if enabled, or by pressing the "Here is" key on the keyboard. The 5-bit ITA2 has an enquiry character, as do the later ASCII and EBCDIC. In the 1960s, Digital Equipment Corporation, DEC routinely disabled the answerback feature on Teletype Model 33 terminals because it inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Standard 1037C
Federal Standard 1037C, titled Telecommunications: Glossary of Telecommunication Terms, is a United States Federal Standard issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. This document provides federal departments and agencies a comprehensive source of definitions of terms used in telecommunications and directly related fields by international and U.S. government telecommunications specialists. As a publication of the U.S. government, prepared by an agency of the U.S. government, it appears to be mostly available as a public domain resource, but a few items are derived from copyrighted sources: where this is the case, there is an attribution to the source. This standard was superseded in 2001 by American National Standard T1.523-2001, Telecom Glossary 2000, which is published by ATIS. The old standard is still frequently used, because the new standard is protected by copyright, as usual f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
End-of-Transmission Character
In telecommunications, an End-of-Transmission character (EOT) is a transmission (telecommunications), transmission control character. Its intended use is to indicate the conclusion of a transmission that may have included one or more texts and any associated message headings. An EOT is often used to initiate other functions, such as releasing circuits, disconnecting terminals, or placing receive terminals in a standby (electricity), standby condition. Its most common use today is to cause a Unix computer terminal, terminal driver to signal end of file and thus exit programs that are awaiting input. In ASCII and Unicode, the character is encoded at . It can be referred to as , in caret notation. Unicode provides the character for when EOT needs to be displayed graphically. In addition, can also be used as a graphic representation of EOT; it is defined in Unicode as "symbol for End of Transmission". Meaning in Unix The EOT character in Unix is different from the Control-Z in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
