ASCII codes represent text in computers, telecommunications equipmentand other devices.
Most modern character-encoding schemes are based on ASCII, although they support many additional characters. ASCII was developed from telegraph code. Its first commercial use was as a seven- bit teleprinter code promoted by Bell data services. The first edition of the standard was published in  underwent a major revision during  and experienced its most recent update during In addition, the original ASCII specification included 33 non-printing хуй нарисованный в ascii codes which originated with Teletype machines ; most of these are now obsolete.
The X3 committee made other changes, including other new characters the brace and vertical bar characters renaming some control characters SOM became start of header Хуй нарисованный в ascii and moving or removing others RU was removed. They proposed a 9-track standard for magnetic tape, and attempted to deal with хуй нарисованный в ascii punched card formats. Like other character encodingsASCII specifies a correspondence between digital bit patterns and character symbols i.
This allows digital devices to communicate with each other and to process, store, and communicate character-oriented information such as written language. Before ASCII was developed, the encodings in use included 26 alphabetic characters, 10 numerical digitsand from 11 to 25 special graphic symbols.
The committee debated the possibility of a shift function like in ITA2which would allow more than 64 codes to be хуй нарисованный в ascii by a six-bit code. In a shifted code, some character codes determine choices between options for the following character codes.
It allows compact encoding, but is less reliable for data transmissionas an error in transmitting the shift code typically makes a long part of the transmission unreadable. The committee considered an eight-bit code, since eight bits octets would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal.
However, it would require all data transmission to send eight bits when seven could suffice. The committee voted to хуй нарисованный в ascii a seven-bit code to minimize costs associated with data transmission.
Since perforated tape at the time could record eight bits in one position, it also хуй нарисованный в ascii for a parity bit for error checking if desired.
The code itself was patterned so that most control codes were together and all graphic codes were together, for ease of identification. The committee decided it was important to support uppercase character alphabetsand chose to pattern ASCII so it could be reduced easily to a usable character set of graphic codes, : Lowercase letters were therefore not interleaved with uppercase.
To keep options available for lowercase letters and other graphics, the special and numeric codes were arranged before the letters, and the letter A was placed in position 41 hex to match the draft of the corresponding British standard. Many of the non-alphanumeric characters were positioned to correspond to their shifted position on typewriters; an important subtlety is that these were based on mechanical typewriters, not electric typewriters.
This discrepancy from typewriters led to bit-paired keyboardsnotably the Teletype Model 33хуй нарисованный в ascii used the left-shifted layout corresponding to Хуй нарисованный в ascii, not to traditional mechanical typewriters. These were positioned to maximize the Hamming distance between their bit patterns. ASCII reserves the first 32 codes numbers 0—31 decimal for control characters: For example, character 10 represents the "line feed" function which causes a printer to advance its paperхуй нарисованный в ascii character 8 represents "backspace".
Other schemes, such as markup languagesaddress page and document layout and formatting. The ambiguity this caused was sometimes intentional, for example where a character would хуй нарисованный в ascii used slightly differently on a terminal link than on a data streamand sometimes accidental, for example with the meaning of "delete". Paper хуй нарисованный в ascii was a very popular medium for long-term program storage until the s, less costly and in some ways less fragile than magnetic tape.
The Model 33 was also notable for taking the description of Control-G хуй нарисованный в ascii 7, BEL, meaning audibly alert the operator literally, as the unit contained an actual bell which it rang when it received a BEL character.
Because the keytop for the O key also showed a left-arrow symbol from ASCII, which had this character instead of underscorea noncompliant use of code 15 Control-O, Shift In interpreted as "delete previous character" was also adopted by many early timesharing systems but eventually became neglected.
This technique became adopted by several early computer operating systems as a "handshaking" signal warning a sender to stop transmission because of impending overflow; it persists to this day in many systems as a manual output control technique.
Code is officially named хуй нарисованный в ascii but the Teletype label was "rubout". Since the original standard did not give detailed interpretation for most control codes, interpretations of this code varied. The original Teletype meaning, and the intent of the standard, was to make it an ignored character, the same as NUL all zeroes.
This was useful specifically for paper tape, because punching the all-ones bit pattern on top of an existing mark would obliterate it. Operating systems from Digital Equipment Corporationfor example, interpreted DEL as an input character as meaning "remove previously-typed input хуй нарисованный в ascii,   and this interpretation also became common in Unix systems.
Most other systems used BS for that meaning and used DEL to mean "remove the character хуй нарисованный в ascii the cursor".
Хуй нарисованный в ascii more of the control codes have been given meanings quite different from their original ones. Хуй нарисованный в ascii "escape" character ESC, code 27for example, was intended originally to allow sending other control characters as literals instead of invoking their meaning. This is the same хуй нарисованный в ascii of "escape" encountered in URL encodings, C language strings, and other systems where certain characters have a reserved meaning. Over time this meaning has been co-opted and has eventually been changed.
An ESC sent from the terminal is most often used as an out-of-band character used хуй нарисованный в ascii terminate an operation, as in the TECO and vi text editors. In graphical user interface GUI and windowing systems, ESC generally causes an application to abort its current operation or to exit terminate altogether.
The inherent ambiguity of many control characters, combined with their historical usage, created problems when transferring "plain text" files between systems. The best example of this is the newline problem on various operating systems. Teletype machines required that a line of text be terminated with both "Carriage Return" which moves the printhead to the beginning of the line and "Line Feed" which advances the paper one line without moving the printhead.
The name "Carriage Return" comes from the fact that on a manual typewriter the carriage holding the paper moved while the position where the typebars struck the ribbon remained stationary.
The entire carriage had to be pushed returned to the right in order to position the left margin of the paper for the next line.
By the time so-called "glass TTYs" later called CRTs or terminals came along, the convention was so well established that backward compatibility necessitated continuing the convention. Unfortunately, requiring two characters to mark the end of a line introduces unnecessary complexity and questions as to how to interpret each character when encountered alone.
To simplify matters plain text data streams, including files, on Multics  used line feed LF alone as a line хуй нарисованный в ascii. Unix and Unix-like systems, хуй нарисованный в ascii Amiga systems, adopted this convention from Multics. The Telnet protocol defined an ASCII " Network Virtual Terminal " NVTso that connections between hosts with different line-ending conventions and character sets could be supported by transmitting a standard text format over the network.
The end-of-text code ETXalso known as Control-Cwas inappropriate for a variety of reasons, while using Z as the control code to end a file is analogous to it ending the alphabet and serves as a very convenient mnemonic aid.
A historically common and still prevalent convention uses the ETX code convention to interrupt and halt a program via an input data stream, usually from a keyboard. Other representations might be used хуй нарисованный в ascii specialist equipment, for example ISO graphics or hexadecimal numbers.
Codes 20 hex to 7E hexknown as the printable characters, represent letters, digits, punctuation marksand a few хуй нарисованный в ascii symbols. There are 95 printable characters in total. Code 20 hexthe "space" characterdenotes the space between words, as produced by the space bar of a keyboard. Since the space character is considered an invisible graphic rather than a control character : Bob Bemer introduced features such as the escape sequence.
On March 11,U. I have also approved recommendations of the Secretary of Commerce regarding standards for recording the Standard Code for Information Interchange on magnetic tapes and paper tapes when they are used in computer operations.
All computers and related equipment configurations brought into the Federal Government inventory on and after July 1, хуй нарисованный в ascii, must have the capability to use the Standard Code for Information Interchange and the formats prescribed by the magnetic tape хуй нарисованный в ascii paper tape standards when these media are used.
As computer technology spread throughout the world, different standards bodies and corporations developed many variations of ASCII to facilitate the expression of non-English languages that used Roman-based alphabets.
From early in its development,  ASCII was intended to be just one of several national variants of an international character code standard. For example, Canada had its own version that supported French characters.
It would share most characters in common, but assign other locally useful characters to several code points reserved for "national use". It does not make any additional codes available, so the same code points хуй нарисованный в ascii different characters in different countries. Escape codes were defined to indicate which national variant applied to a piece of text, but they were rarely used, so хуй нарисованный в ascii was often impossible to know what variant to work with and, therefore, which character a code represented, and in general, text-processing systems could cope with only one variant anyway.
C trigraphs were created to solve this problem for ANSI Calthough their late introduction and inconsistent implementation in compilers limited their use. Eventually, as хуй нарисованный в ascii, and bit and later bit computers began to replace and bit computers as the norm, it became common to use an 8-bit byte to store each character in memory, providing an opportunity for extended, 8-bit, relatives of ASCII.
In most cases these developed as true extensions of ASCII, leaving the original character-mapping intact, but adding additional character definitions after the first i. Most early home computer systems developed their own 8-bit character sets containing line-drawing and game glyphs, and often filled in some or all of the control characters from 0 to 31 with more graphics.
The IBM Хуй нарисованный в ascii defined code pagewhich replaced the control characters with graphic symbols such as smiley facesand mapped additional graphic characters to the upper positions. The Macintosh defined Mac OS Roman and Postscript also defined a set, both of these contained both international letters and typographic punctuation marks instead of graphics, more like modern character sets.
A popular further extension designed by Microsoft, Windows often mislabeled as ISOadded the typographic punctuation marks needed for traditional text printing.
From Wikipedia, the free encyclopedia. This article is about the character encoding. Basic Latin Unicode block. Some browsers may not display these properly. On most text terminals, holding down the Ctrl key while typing the second character will type the control character.
To delete the previous character, one had to back up the paper tape punch, which хуй нарисованный в ascii mechanical and хуй нарисованный в ascii reasons was a button on the punch itself and not the keyboard, then type the rubout character.
They therefore placed a key producing rubout at the location used on typewriters for backspace. Other terminals not designed for paper tape made the key at this location produce Backspace, and systems designed for these used that character to back up.
Since the хуй нарисованный в ascii code often produced a backspace effect, this also forced terminal manufacturers to make any Delete key produce something other than the Delete character. However, it is understood by several compilers, including GCC. The Systems Programming Series 1 ed.
Addison-Wesley Publishing Company, Inc. Archived PDF from the original on May 26, American Standard Code for Information Infiltration". Archived from the original on Principles, Devices and Applications.
John Wiley and Sons. In addition, it defines codes for 33 nonprinting, mostly obsolete control characters that affect how the text хуй нарисованный в ascii processed. Best of Interface Age. Archived from the original on August 27,
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