List of binary codes
Encyclopedia
This is a list of some binary codes that are (or have been) used to represent text
as a sequence of binary digits "0" and "1". Fixed-width binary codes use a set number of bits to represent each character in the text, while in variable-width
binary codes, the number of bits may vary from character to character.
systems.
Five bits per character only allows for 32 different characters, so many of the five bit codes used two sets of characters per value referred to as FIGS (figures) and LTRS (letters), and reserved two characters to switch between these sets. This effectively allowed the use of 60 characters.
The following early computer systems each used their own five-bit codes:
More general five-bit standard codes are:
Finally, the steganographic code commonly known as Bacon%27s cipher uses groups of 5 binary valued elements to represent letters of the alphabet.
Examples of six-bit binary codes are:
Each have 1 or more than two numbers 1100101110110
See also: Six-bit character codes
Data compression
systems such as Lempel–Ziv–Welch are able to compress arbitrary binary data. They are therefore not binary codes themselves, but may be applied to binary codes to reduce storage needs
Plain text
In computing, plain text is the contents of an ordinary sequential file readable as textual material without much processing, usually opposed to formatted text....
as a sequence of binary digits "0" and "1". Fixed-width binary codes use a set number of bits to represent each character in the text, while in variable-width
Variable-length code
In coding theory a variable-length code is a code which maps source symbols to a variable number of bits.Variable-length codes can allow sources to be compressed and decompressed with zero error and still be read back symbol by symbol...
binary codes, the number of bits may vary from character to character.
Five-bit binary codes
A number of different five-bit codes were used for early punched tapePunched tape
Punched tape or paper tape is an obsolete form of data storage, consisting of a long strip of paper in which holes are punched to store data...
systems.
Five bits per character only allows for 32 different characters, so many of the five bit codes used two sets of characters per value referred to as FIGS (figures) and LTRS (letters), and reserved two characters to switch between these sets. This effectively allowed the use of 60 characters.
The following early computer systems each used their own five-bit codes:
- J. Lyons and Co.J. Lyons and Co.J. Lyons & Co. was a market-dominant British restaurant-chain, food-manufacturing, and hotel conglomerate founded in 1887 as a spin-off from the Salmon & Gluckstein tobacco company....
LEO (Lyon's Electronic Office) - English ElectricEnglish ElectricEnglish Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...
DEUCEEnglish Electric DEUCEThe DEUCE was one of the earliest British commercially available computers, built by English Electric from 1955.It was the production version of the Pilot ACE, itself a cut down version of Alan Turing's ACE.... - University of Illinois at Urbana-ChampaignUniversity of Illinois at Urbana-ChampaignThe University of Illinois at Urbana–Champaign is a large public research-intensive university in the state of Illinois, United States. It is the flagship campus of the University of Illinois system...
ILLIACILLIACILLIAC was a series of supercomputers built at a variety of locations, some at the University of Illinois at Urbana-Champaign. In all, five computers were built in this series between 1951 and 1974... - ZEBRAZEBRA (computer)The ZEBRA was one of the first computers to be designed in the Netherlands, and one of the first Dutch computers to be commercially available...
- EMI 1100EMIDEC 1100-External links:**...
- Ferranti MercuryFerranti MercuryThe Mercury was an early 1950s commercial computer built by Ferranti. It was the successor to the Ferranti Mark 1, adding a floating point unit for improved performance, and increased reliability by replacing the Williams tube memory with core memory and using more solid state components...
, Pegasus, and OrionFerranti OrionThe Orion was a mid-range mainframe computer introduced by Ferranti in 1959 and installed for the first time in 1961. Ferranti positioned Orion to be their primary offering during the early 1960s, complementing their high-end Atlas and smaller systems like the Sirius and Argus...
systems
More general five-bit standard codes are:
- International Telegraph Alphabet No 1Baudot codeThe Baudot code, invented by Émile Baudot, is a character set predating EBCDIC and ASCII. It was the predecessor to the International Telegraph Alphabet No 2 , the teleprinter code in use until the advent of ASCII. Each character in the alphabet is represented by a series of bits, sent over a...
(ITA1) - Also commonly referred to as Baudot code - International Telegraph Alphabet No 2 (ITA2) - Also commonly referred to as Murray code
- American Teletypewriter code (USTTY) - A variant of ITA2 used in the USA
- DIN 66006 - Developed for presentation of ALGOLALGOLALGOL is a family of imperative computer programming languages originally developed in the mid 1950s which greatly influenced many other languages and became the de facto way algorithms were described in textbooks and academic works for almost the next 30 years...
/ALCORALCORALCOR is an early computer language definition created by the ALCOR Group, a consortium of universitites, research institutions and manufacturers in Europe and the USA which was founded in 1959 and which had 60 members in 1966. The group had the aim of a common compiler specification for a subset...
programs on paper tape and punch cards
Finally, the steganographic code commonly known as Bacon%27s cipher uses groups of 5 binary valued elements to represent letters of the alphabet.
Six-bit binary codes
Six bits per character allows 64 distinct characters to be represented.Examples of six-bit binary codes are:
- International Telegraph Alphabet No 3 (ITA3) - derived from the Moore ARQ code, and also known as the RCA code.
- Six-bit BCDBCD (6-bit)Six-bit BCD code , alphanumeric BCD, or alphameric BCD is a six-bit character code used by mainframe computers to represent the numerals, the Latin letters, and some additional characters...
(Binary Coded Decimal), used by early mainframeMainframe computerMainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
computers. - BrailleBrailleThe Braille system is a method that is widely used by blind people to read and write, and was the first digital form of writing.Braille was devised in 1825 by Louis Braille, a blind Frenchman. Each Braille character, or cell, is made up of six dot positions, arranged in a rectangle containing two...
- Braille characters are represented using six dot positions, arranged in a rectangle. Each position may contain a raised dot or not, so Braille can be considered to be a six-bit binary code.
Each have 1 or more than two numbers 1100101110110
See also: Six-bit character codes
Seven-bit binary codes
Examples of seven-bit binary codes are:- ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
- The ubiquitous ASCII code was originally defined as a seven-bit character set. The ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
article provides a detailed set of equivalent standards, and variants. In addition, there are various extensions of ASCII to eight-bits (see Eight-bit binary codes) - CCIR 476 - Extends ITA2 from 5 to 7 bits, using the extra 2 bits as check digitsParity bitA parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code....
- International Telegraph Alphabet No 4 (ITA4)
Eight-bit binary codes
- Extended ASCII - A number of standards extend ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
to eight bits by adding a further 128 characters, such as:- ISO/IEC 8859ISO/IEC 8859ISO/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...
- Mac OS RomanMac OS RomanMac OS Roman is a character encoding primarily used by Mac OS to represent text. It encodes 256 characters, the first 128 of which are identical to ASCII, with the remaining characters including mathematical symbols, diacritics, and additional punctuation marks. It is suitable for use to represent...
- Windows-1252Windows-1252Windows-1252 or CP-1252 is a character encoding of the Latin alphabet, used by default in the legacy components of Microsoft Windows in English and some other Western languages. It is one version within the group of Windows code pages...
- ISO/IEC 8859
- EBCDICEBCDICExtended Binary Coded Decimal Interchange Code is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems....
- Used in early IBMIBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
computers and current System iIBM System iThe IBM System i is IBM's previous generation of midrange computer systems for IBM i users, and was subsequently replaced by the IBM Power Systems in April 2008....
and System z computers
10 bit binary codes
- AUTOSPEC - Also known as Bauer code. AUTOSPEC repeats a five-bit character twice, but if the character is one with odd parity, the repetition is inverted
16 bit binary codes
- UCS-2 - An obsolete encoding capable of representing the basic multilingual plane of Unicode
32 bit binary codes
- UTF-32/UCS-4UTF-32/UCS-4UTF-32 is a protocol to encode Unicode characters that uses exactly 32 bits per Unicode code point. All other Unicode transformation formats use variable-length encodings. The UTF-32 form of a character is a direct representation of its codepoint.The main advantage of UTF-32, versus variable...
- A four-bytes-per-character representation of UnicodeUnicodeUnicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
Variable length binary codes
- UTF-8UTF-8UTF-8 is a multibyte character encoding for Unicode. Like UTF-16 and UTF-32, UTF-8 can represent every character in the Unicode character set. Unlike them, it is backward-compatible with ASCII and avoids the complications of endianness and byte order marks...
- Encodes characters in a way that is mostly compatible with ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
but can also encode the full repertoire of Unicode characters with sequences of up to 4 8-bit bytes - UTF-16 - Extends UCS-2 to cover the whole of Unicode with sequences of 1 or 2 16-bit elements
- GB 18030GB 18030GB18030 is a Chinese government standard describing the required language and character support necessary for software in China. In addition to the "GB18030 code page" this standard contains requirements about which scripts must be supported, font support, etc....
- A full-Unicode variable length code designed for compatibility with older Chinese multibyte encodings - Huffman codingHuffman codingIn computer science and information theory, Huffman coding is an entropy encoding algorithm used for lossless data compression. The term refers to the use of a variable-length code table for encoding a source symbol where the variable-length code table has been derived in a particular way based on...
- A technique for expressing more common characters using shorter bit strings than are used for less common characters
Data compression
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
systems such as Lempel–Ziv–Welch are able to compress arbitrary binary data. They are therefore not binary codes themselves, but may be applied to binary codes to reduce storage needs
Other
- Morse codeMorse codeMorse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...
is a variable length telegraphy code, which traditionally uses a series of long and short pulses to encode characters. It relies on gaps between the pulses to provide separation between letters and words, as the letter codes do not have the "prefix property"Prefix codeA prefix code is a type of code system distinguished by its possession of the "prefix property"; which states that there is no valid code word in the system that is a prefix of any other valid code word in the set...
. Morse code can be represented as a binary stream by allowing each bit to represent one unit of time. Thus a "dit" or "dot" is represented as a single 1 bit, while a "dah" or "dash" is represented as three consecutive 1 bits. Spaces between symbols, letters and words are represented as one, three, or seven consecutive 0 bits. For example "UP" in Morse Code is "..- .--.", which could be represented in binary as "101011100010111011101".
External links
- 5 Level Paper Tape Description of 5 bit paper tape encoding schemes.
- 6 Level Paper Tape Description of 6 bit paper tape encoding schemes.
- 7 Level Paper Tape Description of 7 bit paper tape encoding schemes.
- 8 Level Paper Tape Description of 8 bit paper tape encoding schemes.