Translate

Sunday, August 5, 2018

EBCDIC

EBCDIC was devised in 1963 and 1964 by IBM and was announced with the release of the IBM System/360 line of mainframe computers. It is an eight-bit character encoding, developed separately from the seven-bit ASCII encoding scheme. It was created to extend the existing Binary-Coded Decimal (BCD) Interchange Code, or BCDIC, which itself was devised as an efficient means of encoding the two zone and number punches on punched cards into six bits. The distinct encoding of 's' and 'S' (using position 2 instead of 1) was maintained from punched cards where it was desirable not to have hole punches too close to each other to ensure the integrity of the physical card.
While IBM was a chief proponent of the ASCII standardization committee, the company did not have time to prepare ASCII peripherals (such as card punch machines) to ship with its System/360 computers, so the company settled on EBCDIC. The System/360 became wildly successful, together with clones such as RCA Spectra 70, ICL System 4, and Fujitsu FACOM, thus so did EBCDIC.
All IBM mainframe and midrange peripherals and operating systems use EBCDIC as their inherent encoding (with toleration for ASCII, for example, ISPF in z/OS can browse and edit both EBCDIC and ASCII encoded files). Software and many hardware peripherals can translate to and from encodings, and modern mainframes (such as IBM zSeries) include processor instructions, at the hardware level, to accelerate translation between character sets.
There is an EBCDIC-oriented Unicode Transformation Format called UTF-EBCDIC proposed by the Unicode consortium, designed to allow easy updating of EBCDIC software to handle Unicode, but not intended to be used in open interchange environments. Even on systems with extensive EBCDIC support, it has not been popular. For example, z/OS supports Unicode (preferring UTF-16 specifically), but z/OS only has limited support for UTF-EBCDIC.
IBM AIX running on the RS/6000 and its descendants including the IBM Power Systems, Linux running on z Systems, and operating systems running on the IBM PC and its descendants use ASCII, as did AIX/370 and AIX/390 running on System/370 and System/390 mainframes.

Courtesy of Wikipedia

Cumberland Computer Services., LLC
205-467-4055
https://cumberlandcomputerservices.com/

No comments:

Post a Comment