Search results
Results From The WOW.Com Content Network
It is also used as an escape sequence in some programming languages. In the ASCII character set, this character is encoded by the number 26 (1A hex). Standard keyboards transmit this code when the Ctrl and Z keys are pressed simultaneously (Ctrl+Z, often documented by convention as ^Z). [1]
ASCII reserves the first 32 code points (numbers 0–31 decimal) and the last one (number 127 decimal) for control characters. These are codes intended to control peripheral devices (such as printers ), or to provide meta-information about data streams, such as those stored on magnetic tape.
Thus, the number of code units required to represent a code point depends on the encoding: UTF-8: code points map to a sequence of one, two, three or four code units. UTF-16: code units are twice as long as 8-bit code units. Therefore, any code point with a scalar value less than U+10000 is encoded with a single code unit.
Code 0 (ASCII code name NUL) is a special case. In paper tape, it is the case when there are no holes. It is convenient to treat this as a fill character with no meaning otherwise. Since the position of a NUL character has no holes punched, it can be replaced with any other character at a later time, so it was typically used to reserve space ...
Code points are commonly used in character encoding, where a code point is a numerical value that maps to a specific character.In character encoding code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols, control characters, or formatting. [4]
Six-bit BCD code was the adaptation of the punched card code to binary code. IBM applied the terms binary-coded decimal and BCD to the variations of BCD alphamerics used in most early IBM computers, including the IBM 1620 , IBM 1400 series , and non- decimal architecture members of the IBM 700/7000 series .
The ASCII text-encoding standard uses 7 bits to encode characters. With this it is possible to encode 128 (i.e. 2 7) unique values (0–127) to represent the alphabetic, numeric, and punctuation characters commonly used in English, plus a selection of Control characters which do not represent printable characters.
The ASCII "escape" character (octal: \033, hexadecimal: \x1B, or, in decimal, 27, also represented by the sequences ^[or \e) is used in many output devices to start a series of characters called a control sequence or escape sequence. Typically, the escape character was sent first in such a sequence to alert the device that the following ...