Re: ASCII

[Carl Distefano CLDistefano@xxxxxxxx]

Reply to note from Peter Evans  Wed, 31 Mar
1999 12:34:07 +0900

-> If on the other hand it means: "Xy does not use any byte for
-> purposes other than those defined in the IBM character set
-> popularly known as IBM extended ASCII", no: guillemets, the
-> tilde and (in Xy4) character 254 are anomalous.

Also 9 (though the "tab" function associated with it is universal).
Also, the alternate line end (VAriable $DE). And certainly also 0,
26, 253 and 255.

It's worth noting that the "anomalies" aren't all anomalous in the
same way. Many of these -- guillemets, tabs, soft hyphens -- can be
typed manually in eXPanded view and display the same as they do in a
DOS TYPE command. 254 and 255 appear only in special 3-character
sequences and can't be typed in individually (not even in eXPanded
view); they do, however, display readily in a text lister or hex
editor. 0 and 253 are really weird in that (in XyDOS, at least)
they control aspects of the display and can't be used in files at
all. All told, that's a mere 4 or 5 special uses out of a possible
256 -- as you say, "the anomaly-ratio ... is unusually and
commendably low".

What this means, in a nutshell, is that, for a full-featured word
processor, XyWrite's files are remarkably junk-free. Mostly, they
contain the author's words. Formatting codes are compact and easily
identifiable (not to mention human-readable). All the heavy-duty
"binary" stuff -- fonts, page layout and the like -- is handled
elsewhere, by the program. As a result, we have an unusual degree
of control over file content, and the experience of XyWriting
retains much of the immediacy of putting pen to paper.

Ah, but I'm preaching to the choir....


--------------
Carl Distefano
CLDistefano@xxxxxxxx
http://users.datarealm.com/xywwweb/