Re: ASCII

[Stephen Moore essmo@xxxxxxxx]

At 08:08 AM 3/30/99 EST, Tom Hawley (tjh@xxxxxxxx) wrote:

> Technically, XyWrite is not "pure ASCII" but it is "pure 8 bit
> coded character set". And in the PC environment, the former has
> come to be shorthand for the latter.

Well said. The standardized ASCII is a 7-bit coding scheme; use of
the 8th bit is what varies from platform to platform. Pre-IBM PC
WordStar (any former mavens on the list?) set or cleared the 8th bit
for houskeeping purposes, rather than for extending the character set
(at least until WordStar 4). This is why old WordStar files on the PC
appear somewhat weird when seen through a non-filtering viewer or the
DOS TYPE command.

ASCII, BTW, was one of two principal coding schemes back when Atex and
XyWrite were born, the other being the 8-bit EBCDIC scheme used on
IBM's big iron. Maybe they meant "XyWrite's not EBCDIC!" :-)


Also, word processor file structures seem to fall into two general
classes, typified on the one hand by XyWrite (and WordStar before it),
and on the other by the much-reviled MS Word. XyWrite could be said to
use a "streaming" structure (my term), that is, the text runs from
start to finish, and any enhancements are switched on in-stream where
they apply, and are switched off immediately when they no longer apply.
Moreover, the on/off control structures are plainly visible to the
practiced eye.

Word's is a "header/trailer" type of format, wherein the actual text is
an almost perfectly plain block in the middle of the file, preceded and
followed by blocks of formatting information coded in a more or less pro-
prietary way. Obviously this way does not lend itself to parsing by eye,
nor to import by other word processors without filtering software.
IMHO, something similar to this concept is what's really being referenced
by the "pure ASCII" statement.


Apologies if I've restated the obvious here...

Stephen Moore