Character Codes in ASCII

What is ASCII?

ASCII is an 8-bit encoding for the representation of decimal digits, Latin and national alphabets, punctuation marks and control characters. Initially designed as a 7-bit, with a wide spread of 8-bit ASCII bytes began to be perceived as half of the 8-bit byte. In computers, ASCII extensions are usually used with the 8th bit involved and the second half of the code table (for example, KOI-8). The lower half of the code table (0 - 127) is occupied by US-ASCII characters , and the upper (128 - 255) - different other necessary symbols.

ASCII Symbols (ASCII Symbols)

ASCII Symbols (ASCII Symbols) - sometimes using in their nickname various ASCII characters (giving an additional entourage of a particular role), users ask a series of questions about where these same "badges" were taken. In this article, there will be all necessary for trolling and not only, symbols ..

Where, besides trolling, can the above-mentioned symbols come in handy? Yes, everywhere, where ordinary text messages are used: in personal messages vkontakte, incentive, classmates, ICQ, correspondence by mail, in articles, blogs and websites, finally - to give a kind of greater originality text, as well as highlighting significant areas of this text.

Examples of ALL AVAILABLE ASCII characters (opens in a new window).

ASCII Art (ASCII Artwork)

ASCII Art (ASCII Artwork) is the art of drawing using ASCII characters. This can be a notebook or a window of the terminal. Use to display creative pictures.

To create an ASCII drawing, use a palette consisting of digital, alphabetic characters and punctuation marks - a total of 95 characters. The remaining 160 characters, as a rule, do not use, because they are output in different ways in different encodings (for example, UTF-8 and Windows 1251). Enough fun activity

An example of an ASCII work (opens in a new window).

Control characters

Since ASCII was originally intended for information exchange (via teletype), it uses symbols-commands for communication control, in addition to information symbols. This is the usual set of special signals used in other pre-computer messaging systems (Morse code, semaphore alphabet), supplemented with the specificity of the device (after the name of each character, its hex code is indicated).

• NUL, 00 - Null, empty. Always ignored. On the punched tapes 1 was represented by a hole, 0 - by the absence of a hole. Therefore, the empty parts of the punched tape before and after the end of the message consisted of such symbols. Now it is used in many programming languages ​​as the end of the line. (A string is understood as a sequence of characters.) On some operating systems, NUL is the last character of any text file.
• SOH, 01 - Start Of Heading, the beginning of the header.
• STX, 02 - Start of Text, the beginning of the text. The text was the part of the message intended for printing. The address, checksum, etc. were either in the header or in the message after the text.
• ETX, 03 - End of Text, end of text. Here the teletype stopped printing. Using the Ctrl-C character, which has the code 03, to stop the work of something (usually a program), goes back to those times.
• EOT, 04 - End of Transmission, end of transmission. On a UNIX system, Ctrl-D, which has the same code, means the end of the file when typing in from the keyboard.
• ENQ, 05 - Enquire. I ask for confirmation.
• ACK, 06 - Acknowledgment. I confirm.
• BEL, 07 - Bell, bell, beep. Now also used. In C and C ++ programming languages, \ a.
• BS, 08 - Backspace, return to one character. Now the previous character is erased.
• TAB, 09 - Tabulation. HT - Horizontal Tabulation, horizontal tabulation was also indicated. Many programming languages ​​denote \ t.
• LF, 0A - Line Feed, line feed. Now at the end of each line of the text file, either this symbol, or CR, or both (CR, then LF) is put, depending on the operating system. In many programming languages, \ n is indicated and when the text is output, the line is translated.
• VT, 0B - Vertical Tab, vertical tab.
• FF, 0C - Form Feed, page run, new page.
• CR, 0D - Carriage Return, carriage return. In many programming languages, this symbol, denoted by \ r, can be used to return to the beginning of the line without a line feed. On some operating systems, the same symbol, designated Ctrl-M, is placed at the end of each line of the text file before LF.
• SO, 0E - Shift Out, change the color of the ribbon (used for two-colored ribbons, the color usually changed to red). Later it marked the beginning of the use of the national coding.
• SI, 0F - Shift In, back to Shift Out.
• DLE, 10 - Data Link Escape, data channel release - the following symbols represent data, not control characters.
• DC1, 11 - Device Control 1, 1st device control symbol - turn on the punched tape reader.
• DC2, 12 - Device Control 2, 2nd character control device - turn on the punch.
• DC3, 13 - Device Control 3, the 3rd character of the device control - turn off the punched tape reader.
• DC4, 14 - Device Control 4, the 4th character of the device control - turn off the punch.
• NAK, 15 - Negative Acknowledgment, I do not confirm. Back Acknowledgment.
• SYN, 16 - Synchronization. This symbol was transmitted when something needed to be transmitted for synchronization.
• ETB, 17 - End of Text Block, the end of the text block. Sometimes the text for technical reasons was broken into blocks.
• CAN, 18 - Cancel, cancel (what was transferred earlier).
• EM, 19 - End of Medium, the end of the media (the punched tape has run out, etc.)
• SUB, 1A - Substitute, substitute. Put in place of a character whose value was lost or corrupted during transmission. Now Ctrl-Z is used as the end of the file when typing in DOS and Windows systems. This function does not have any obvious connection with the SUB symbol.
• ESC, 1B - Escape. The characters following it have a different meaning than the one defined in ASCII. He usually started control sequences.
• FS, 1C - File Separator, file separator.
• GS, 1D - Group Separator, group separator.
• RS, 1E - Record Separator, record separator.
• US, 1F - Unit Separator, unit separator. That is, 4 levels of data structuring were supported: the message could consist of files, files from groups, groups from records, records from units.
• DEL, 7F - Delete, erase the last character. The symbol DEL, consisting in binary code from all units, it was possible to hammer any symbol. Devices and programs ignored DEL in the same way as NUL. The code of this symbol comes from the first word processors with memory on the punched tape: in them the symbol was deleted by clogging its code with holes (denoting logical units).