[net.graphics] Is ANSI NAPLPS different from Bell NAPLP, May '81

brucec@orca.UUCP (Bruce Cohen) (07/23/83)

Yes.

There are a lot of small, subtle differences, including some sections
added to deal with conformance and how to subset the standard.   There
are several fairly large changes, such as the requirement for a color
map even in color mode 1.  I can't recall all of the differences right
now, but there are a fair number.  The basic functionality is
unchanged (there are no new character sets, or new PDIs, for
instance), but there are enough differences that an implementor would
do well to throw out the Bell spec.  In my opinion, the ANSI document,
dense as it is, is much more readable than the Bell version, in part
because of the addition of some illustrations to *show* what the
graphics are supposed to look like.

If there is a magazine editor out there who wants to publish an article
on the technical differences between the specifications, I'd be willing
to do it, but a point for point analysis would bore most of the people
in this newsgroup, and would be a lot of work, especially as I would
practically have to go through the documents line by line to find all
the changes, so I won't bother.  Anyone else out there is welcome to do
it.

				Bruce Cohen

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brucec@orca.UUCP (Bruce Cohen) (07/25/83)

Correction to minor technical detail, for anyone who cares:  it's
color mode 0 that had the color map added; color mode 1 always
required it.

As an aside, why do people insist on numbering things
from 0?  Is this an attempt to be esoteric?  I always thought that the
reason for labeling arrays from 0 was to make the offset
within an array be easily and intuitively computable.  This doesn't
seem to map well into the realm of counting things, as the high
incidence of "off-by-one" errors in programming shows.

				Bruce Cohen

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