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Extended Binary Coded Decimal Interchange Code (EBCDIC) is an 8-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. EBCDIC 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. It is also employed on various non-IBM platforms such as Fujitsu-Siemens' BS2000/OSD, OS-IV, MSP, and MSP-EX, and Unisys VS/9 and MCP. == History == 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 8-bit character encoding, in contrast to, and developed separately from, the 7-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 6 bits. While IBM was a chief proponent of the ASCII standardization committee,〔(They had 4 staff on the final 21-member ASA X3.2 sub-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.〔(''"...but their printers and punches were not ready to handle ASCII, and IBM just HAD to announce."'' ), EBCDIC and the P-Bit, Bob Bemer〕 The System/360 became wildly successful, and 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「EBCDIC」の詳細全文を読む スポンサード リンク
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