RE: Microsoft's ANSI Character Set

From: Paul Dempsey (Exchange) (
Date: Tue Jun 08 1999 - 13:07:24 EDT

Asmus gives a good history.

ANSI does not refer to any specific character set, codepage, or standard.
Today, 'ANSI' in Windows documentation just means the current system
codepage or SBCS/DBCS/MBCS codepages in general. You can think of it as the
name for "not Unicode".

--- Paul Chse Dempsey
Microsoft Visual Studio Text Editor Development

> -----Original Message-----
> From: Asmus Freytag []
> Sent: Tuesday, June 08, 1999 5:21 AM
> To: Unicode List
> Subject: Re: Microsoft's ANSI Character Set
> Before the ISO standard, what was to become 8859-1 was an ANSI draft.
> One of the early Windows developers must have been plugged in enough
> to get ahold of this document and based the code page on it.
> That was in the mid eighties sometime.
> 'ANSI' stood in contrast to 'OEM' (read DOS) character set,
> and this is
> reflected all over function names and manuals from the earliest days.
> This was handy, since with windows 3.1 there were many international
> code pages, all paired off with a local DOS code page. ANSI on the
> screen, OEM in filenames (and more often than not in those days, in
> plain text files).
> With NT, 'ANSI' could be paired off again, this time against Unicode.
> All function entry points now exist in two versions an A (from ANSI)
> and a W (for wchar_t or wide character) version.
> Important to note is that the original ANSI set (in Windows) followed
> 8859-1 strictly and then with CP 1252 became a superset. The other
> parts of 8859 did not fare that well: they each have a corresponding
> code page that can cover the repertoire, but with a little bit
> scrambled layout to allow a set of common characters in common
> positions.
> Customers wanted to be able to run US or Latin-1 based software and
> did not care to see the paragraph marks, curly quotes, and other
> characters used in the UI, change to random local characters. On
> could say the market voted for a larger *common* subset than 96
> ASCII characters already then.
> With Unicode the times of careful tweaking of 8-bit sets for minor
> advantage has hopefully come to an end.
> A./
> At 04:41 AM 6/8/99 -0700, Markus Kuhn wrote:
> >A question, just to satisfy my historic interest:
> >
> >Why is the MS-Windows documentation full of references to the "ANSI
> >character set" and what ANSI standard does this refer to?
> >
> >It this just ANSI/ISO 8859-1 or has CP1252 at some point become
> >an ANSI standard?
> >
> >Some branches of the (low end) computing literature have
> become full of
> >references to the "ANSI character set", but know body seems
> to know what
> >that means, except that everyone copies it from Microsoft documents.
> >Indeed it seems that references to the "ANSI character set"
> have become
> >a good indicator for the general level of competence of the
> author of a
> >computing publication.
> >
> >Markus
> >
> >--
> >Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
> >Email: mkuhn at, WWW: <>
> >
> >
> >

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