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Re: ANSIfied XyWrite



One could add that ANSI is the character set used by
Windows but not by Dos or the Mac.  Just to give an idea
of the differences:

ANSI uses the range 192 to 255 for accented characters -
neatly laid out with each lowercase character exactly 32
above its uppercase equivalent. The range 128 to 191
contains miscellaneous characters - the copyright symbol
for instance.

The Dos 437 character set puts accented characters between
128 and 175, line drawing characters between 176 & 223,
Greek characters and other oddities from 224 to 255.

As an example, character code 233 is an acute e é character
under ANSI but a Greek theta character under Dos.

In addition, Hewlett Packard - for one - has sets of its
own - Roman 8 and Latin 1 are examples - in addition
to the standard ones.

If one wants to print characters which aren't in the
character set one's using, there are two basic substitution
possibilities, depending on what one's printer has in its
quiver.

- one is to manufacture the accented character using other
characters - to print an e acute é, one might print the e,
tell the printer to go back one position then print the
character which most closely resembles the accent in
question (as in Michael Norman's quote of Norman Havens).
(Alternatively, one can use a language like PCL or
Postscript to draw any shape one wants: somewhere in Xy
documentation is a description of how Xyquest used this
method in their program documentation to print a character
unavailable in any character set. The Postscript character
set I believe has very few accented characters as such; it
has a full set of accents though and Postscript printer
drivers use this method to manufacture accented characters
at print time (someone will no doubt correct me if this
isn't the case).)

- the other is to find a character set in the printer's
repertoire which has the accented character in question and
get Xy's substitution table to issue the commands for
switching to that character set, printing the accented
character in question then switching back to the default
character set.

In each case, one has to choose a fall-guy - some character
which is available in the on-screen character set but
which will be converted to the wanted character during
printing.

If though one simply wants to transfer text from dos to
windows, a simple xpl program can do the conversions (where,
that is, the characters exist in both sets: Dos doesn't have
a copyright symbol, ANSI doesn't have Greek characters.
And neither has Postscript's set of accents-on-their-own.)

Unicode holds out the promise of an end to this chaos. It
isn't limited to 255 characters - it has 65000+.  So
everyone in the world will find what they want in one and
the same character set. With the tradeoff that file sizes will
tend to double.

John

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