"ASCII" is a term of art defined by ANSI, just as 8859-1 is a term of art defined by ISO. EBCDIC is a term of art defined by IBM, and IBM has always had multiple code page for it.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Alan Altmark <[email protected]> Sent: Monday, February 26, 2018 3:45 PM To: [email protected] Subject: Re: Cobol EBCDIC to ASCII On Tue, 20 Feb 2018 14:35:57 +0000, Seymour J Metz <[email protected]> wrote: >The problem is not that the term "ASCII" is ambiguous; it isn't. The problem >is that people don't understand what ASCII is and > refer to things that aren't ASCII as "ASCII". Code pages like 437, 850 and > ISO-8859-x aren't ASCII, and if IBM documentation > refers to them as ACII then that is a disservice to your customers. > >There are, however, issues as to how ASCII should be converted to other code >pages. For example, ASCII defines a broken > vertical bar, nut it is common to display | as a solid vertical bar. Many > code pages have both characters, and either choice > can lead to problems. At a point in history, "ASCII" and "EBCDIC" meant only one thing, but they have since evolved. They retained, however, their core DNA. It is to that DNA we refer when we say their names without qualification. The term "US-ASCII" refers to the original 7-bit specification adopted by ANSI as X3.4. It is preserved in IBM code page 367. The nice thing about ASCII is that all descendants of US-ASCII simply added characters 128 to 255. The first 128 code points remained untouched. How a platform displayed the 32 control characters in a non-control context, or the appearance of undefined code point 0x7f (i.e. in a character generator), was beyond the scope of the ANSI standard. EBCDIC, on the other hand, suffered under the strain of trying to maintain compatibility with its BCD ancestor, the needs of the different programming languages, a recalcitrant ANSI standards committee, and the limitations of the hardware at the time ("Thank you, Mr. Hollerith!"). There was apparently an objective that EBCDIC have all the graphics of ASCII and none that ASCII did not. "Men plan, gods laugh." There were too many participants at the table and compromises were made that we deal with today. The equivalence eventually made it into the literature as IBM code page 38. Right. I don't use it, either. The book "Coded Character Sets, History and Development" by Charles Mackenzie, IBM (Addison-Wesley, System Programming Series, 1980) is as fascinating as it is horrifyingly geeky. Alan Altmark IBM ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
