<character, standard> /eb's*-dik/, /eb'see'dik/, /eb'k*-dik/, /ee'bik'dik'/, /*-bik'dik'/ (EBCDIC) A proprietary 8-bit character set used on IBM dinosaurs, the AS/400, and e-Server. EBCDIC is an extension to 8 bits of BCDIC (Binary Coded Decimal Interchange Code), an earlier 6-bit character set used on IBM computers. EBCDIC was [first?] used on the successful System/360, anounced on 1964-04-07, and survived for many years despite the almost universal adoption of ASCII elsewhere. Was this concern for backward compatibility or, as many believe, a marketing strategy to lock in IBM customers? IBM created 57 national EBCDIC character sets and an International Reference Version (IRV) based on ISO 646 (and hence ASCII compatible). Documentation on these was not easily accessible making international exchange of data even between IBM mainframes a tricky task. US EBCDIC uses more or less the same characters as ASCII, but different code points. It has non-contiguous letter sequences, some ASCII characters do not exist in EBCDIC (e.g. square brackets), and EBCDIC has some (cent sign, not sign) not in ASCII. As a consequence, the translation between ASCII and EBCDIC was never officially completely defined. Users defined one translation which resulted in a so-called de-facto EBCDIC containing all the characters of ASCII, that all ASCII-related programs use. Some printers, telex machines, and even electronic cash registers can speak EBCDIC, but only so they can converse with IBM mainframes. For an in-depth discussion of character code sets, and full translation tables, see {Guidelines on 8-bit character codes (ftp://ftp.ulg.ac.be/pub/docs/iso8859/iso8859.networking)}. {A history of character codes (http://tronweb.super-nova.co.jp/characcodehist.html)}. E.g. the EBCDIC code for "A" is hexadecimal "C1". (2002-03-03)

Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding six-bit binary-coded decimal code used with most of IBM's computer peripherals of the late 1950s and early 1960s.

Extended Binary Coded Decimal Interchange Code

<spelling> It's spelled "EBCDIC". (1996-12-13)

Extended Binary-Coded Decimal Interchange Code

binary coded decimal

In computing and an electronic systems, binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each digit is represented by a fixed number of bits, usually four or eight. Sometimes, special bit patterns are used for a sign or other indications (e.

<data> (BCD, packed decimal) A number representation where a number is expressed as a sequence of decimal digits and then each decimal digit is encoded as a four-bit binary number (a nibble). E.g. decimal 92 would be encoded as the eight-bit sequence 1001 0010. In some cases, the right-most nibble contains the sign (positive or negative). It is easier to convert decimal numbers to and from BCD than binary and, though BCD is often converted to binary for arithmetic processing, it is possible to build hardware that operates directly on BCD. [Do calculators use BCD?] (2001-01-27)

Natural Binary Coded Decimal

<hardware> A binary sequence with the property that only one bit changes between any two consecutive elements (the two codes have a Hamming distance of one). The Gray code originated when digital logic circuits were built from vacuum tubes and electromechanical relays. Counters generated tremendous power demands and noise spikes when many bits changed at once. E.g. when incrementing a register containing 11111111, the back-EMF from the relays' collapsing magnetic fields required copious noise suppression. Using Gray code counters, any increment or decrement changed only one bit, regardless of the size of the number. Gray code can also be used to convert the angular position of a disk to digital form. A radial line of sensors reads the code off the surface of the disk and if the disk is half-way between two positions each sensor might read its bit from both positions at once but since only one bit differs between the two, the value read is guaranteed to be one of the two valid values rather than some third (invalid) combination (a glitch). One possible algorithm for generating a Gray code sequence is to toggle the lowest numbered bit that results in a new code each time. Here is a four bit Gray code sequence generated in this way: 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0 0 1 1 0 0 1 1 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 1 0 1 0 1 1 1 0 0 1 1 0 0 0 The codes were patented in 1953 by Frank Gray, a Bell Labs researcher. http://nist.gov/dads/HTML/graycode.html. (2002-08-29)