I thought PostScript was PostScript!?!

[Brent Chapman]

# I've produced a PostScript program which prints nicely on our Apple Laser
# Writer when I type "lpr -h myfile" (where 'myfile' is PostScript source)
# from my Sun who runs Transcript.  The PROBLEM begins when I try to have a
# local laser-print shop print 'myfile' on their LaserWriter, and
# ultimately, on their Linotronic 2540 dpi printer.  They say that printing
# fails.
# 
# So any clues?  Does lpr prepend a prologue to 'myfile' which I in turn do
# not give to the print shop?

Perhaps just the opposite.  They may be treating the file like a Mac
document, and prepending (or preinstalling in the printer) a Mac driver or
prologue. 

Alternatively, they may expect your program to be "structured", according
to the structuring specificiations in Appendix C of the PostScript
Language Reference Manual (more commonly known as "the red book") from
Adobe.  If possible, you should follow those conventions, but if you
_don't_, make sure that your file doesn't still _claim_ to follow the
conventions.  "%!" as the first two characters of the file identify it as
PostScript; "%!PS-Adobe-1.0" on the first line identifies it as conformant
with version 1.0 of the structuring conventions.

The structuring conventions, if you're curious, are what allow people to
write filter programs that can do neat things like reverse the order of
printing (print pages in descending order, instead of ascending order),
select only certain pages from a file for printing (only pages 5-10 and
20, for instance), and so on.  There are many other uses for the
structuring conventions, and I believe they are, on the whole, a Good
Thing, and that it is worth the little bit of extra trouble it takes to
generate PostScript that conforms to the conventions.


-Brent
--
Brent Chapman					Capital Market Technology, Inc.
Computer Operations Manager			1995 University Ave., Suite 390
brent at capmkt.com				Berkeley, CA  94704
{apple,lll-tis,uunet}!capmkt!brent		Phone:  415/540-6400