Editing EBCDIC (section)

== History ==
[[File:Blue-punch-card-front-horiz top-char-contrast-stretched.png|thumb|upright=1.888|[[Punched card]] with the Hollerith encoding of the 1964 EBCDIC character set. Contrast at the top is enhanced to show the printed characters. The "number" punches (0–9) directly translate to the lower 4 bits of EBCDIC, though the upper 4 bits of EBCDIC are more complex.]]
EBCDIC was devised in 1963 and 1964 by [[IBM]] and was announced with the release of the [[IBM System/360]] line of mainframe [[computer]]s. 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#IBM|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.<ref>{{Cite web |title=Doug Jones's punched card codes |url=http://homepage.cs.uiowa.edu/~jones/cards/codes.html |access-date=2023-01-14 |website=homepage.cs.uiowa.edu}}</ref>{{failed verification|date=January 2023}}

While IBM was a chief proponent of the ASCII standardization committee,<ref name="SR-IX"/> 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.<ref name="Bemer_P-Bit"/> 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's mainframe [[operating system]]s, and its [[IBM i]] operating system for [[midrange computer]]s, use EBCDIC as their inherent encoding<ref name="ibmebcdic"/> (with toleration for ASCII, for example, [[ISPF]] in [[z/OS]] can browse and edit both EBCDIC and ASCII encoded files). Software can translate to and from encodings, and modern mainframes (such as [[IBM Z]]) include processor instructions, at the hardware level, to accelerate translation between character sets. Modern z/OS compilers for the C and C++ languages on [[IBM Z]] mainframes, and earlier [[OS/390]] C and C++ compilers on [[IBM System/390]] mainframes, support a POSIX-compatible execution environment that makes use of ASCII by default.<ref>{{cite web|url=https://www.ibm.com/docs/en/zos/3.1.0?topic=pages-enhanced-ascii|title=Enhanced ASCII|work=z/OS UNIX System Services Planning|date=2024-08-28}}</ref>

Not all operating systems running on IBM hardware use EBCDIC; [[IBM AIX]], [[Linux on IBM Z]], and [[Linux on Power]] all use ASCII, as do all operating systems that run on the [[IBM Personal Computer]] and its successors.