EBCDIC
EBCDIC (Fully, "Extended Binary Coded Decimal Interchange Code") is an 8 bit character encoding used on IBM mainframes and AS/400s. It is descended from punched cards and the corresponding six bit Binary Coded Decimal Code that most of IBM's computer peripherals of the late 1950s and early 1960s used. Outside of such IBM systems, ASCII (and its descendants such as Unicode) are normally used instead; EBCDIC is generally considered an anachronism.
EBCDIC takes up eight bits, which are divided in two pieces. The first four bits are called the zone and represent the category of the character, whereas the last four bits are the called the digit and identify the specific character. There are a number of different versions of EBCDIC, customised for different countries.
History
EBCDIC was devised in 1963-1964 timeframe by IBM and announced with the release of the IBM System/360 line of mainframe computers at the apex of IBM’s mainframe monopoly. It was designed to be better than ASCII, i.e. different and make it difficult for IBM customers to port their data to non-IBM machines. It was an 8 bit encoding, vs. the 7 bit encoding of ASCII and included encodings for all possible punch card codes—an important feature at the time. But the Roman alphabet characters were non-contiguous, a great annoyance.
All IBM mainframe peripherals and operating systems used EBCDIC. Their only lip service to ASCII was to provide an ASCII mode for reading magnetic tapes.
External links
- http://www.legacyj.com/cobol/ebcdic.html
- http://www.geocities.com/mikes_javascript/hex_table_ascii.html
Referenced By
2780 | 3780 | ASCII | ASCIIZ | ASCII code | ASCIIbetical | American Standard Code for Information Interchange | Baudot code | Binary-coded decimal | Binary Coded Decimal | Binary Synchronous Transmission | Bisync | Carriage return | Carrying return | Case-sensitive | Case sensitive | Case sensitivity | Category:list | Character code | Character encoding | Character set | Charset | Codepage | ComputinG | Digital Equipment Company | Digital Equipment Corp. | Digital Equipment Corporation | Double Byte Character Set | Glossary of Coding Terms | IBM 1401 | IBM 1460 | IBM 360 | ISO/OSI Reference Model | ITA2 code | Layer 2 | List of Refernce Tables | List of computing topics | List of initialisms | List of intellectual/social/spiritual/artistic reference tables | List of list of pages | List of lists | List of lists of lists | List of reference tables | List of standards topics | Lists | Millennium Bug | New line | OSI Model | OSI reference model | OSI seven-layer model | OSI seven layer model | Open Systems Interconnection--Reference Model | Presentation Layer | Proprietary lock-in | Punch Card | Punchcard | Punched card | S/360 | System/360 | System 360 | US-ASCII | Uudecode | Uuencode | Y2K bug | Year 2000 bug | Year 2000 problem
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