Imagen postscript problems

[Ed Arnold]

I posed a question in these newsgroups on March 23, asking how to
get postscript files prepared on a Mac, to print properly on an
Imagen 2308S running 4.0 software with Ultrascript.  This posting
provides the solutions that were suggested by Imagen software support,
and several net readers.

The problem is in the dictionary provided by Apple.  The result of
doing an option-K on your Mac, just after clicking on OK in the print
dialogue box, is a postscript file which contains Apple's postscript
dictionary, followed by the output of the application you created a
drawing with.  The dictionary, which is the header of the file, looks like:

%!
%%Title: "Laser Prep -- The Apple PostScript Dictionary (md)"
%%Creator: Apple Software Engineering
%%CreationDate: Thursday, March 19, 1987
%{appledict version #68 0
% (c) CopyRight Apple Computer, Inc. 1984,1985,1986,1987,1988 All Rights Reserved.
%%EndComments
%%BeginProcSet: "(AppleDict md)" 68 0
	.
	.
	.
%%EndProcSet
%%EOF

There are two ways of dealing with this problem.  The first and
definitely the simplest, is simply to use Imagen's Apple compatibility
dictionary corresponding to the version of LaserPrep your Mac puts
out.  For LaserPrep 5.2, that means replacing the entire dictionary
shown above with the two lines:

%!
(dictv52.ps)run

"dictv5.ps", "dictv51.ps", and "dictv52.ps" are postscript dictionaries
which Imagen provides on their hard disk; you can use your Imagen disk
manager program to verify they're there.

The second (and more involved) way of dealing with the problem, is
to fixup Apple's dictionary.  Two fixups are needed.  The first fixup
is at approximately line 9 of the dictionary, which reads:

statusdict begin waittimeout 300 lt{0 60 300 setdefaulttimeouts}if end

This line attempts to set "statusdict" operators that are normally
protected, which results in an "invalidaccess" error on Imagen.
(I presume the LaserWriter must be executing something behind our
backs to get this to work as is.)
To fix it, either (1) place a "serverdict begin <password> exitserver"
command before the above line, or (2) comment out the above line by
placing a '%' before it.

The second needed fixup is at approximately lines 10 & 11 of the
dictionary.  To each of the strings "//setrealdevice" and "//execjob",
prepend a '%' (so they're commented out) and append a '\n' (newline).
(No, I don't know what "setrealdevice" and "execjob" do, they aren't
in Adobe's ps ref manual, appendix D.6 - SYSTEM PARAMETERS.  Must be
Apple-specific stuff.  If you know, please tell me too.)

I should probably mention that several persons pointed me at host
sumex-aim.stanford.edu, which contains contributed programs for the
Mac.  Specifically, they suggested that I look at "macps-prepfix.shar",
which contains programs "macps" and "prepfix", one of whose functions
is to prepend a standard Apple dictionary to a postscript program
on a unix host, before sending it to a LaserWriter.  These programs
aren't very useful with an Imagen, as it's a lot easier just to add
that "(dictv52.ps)run" command to your postscript files, before spooling
them to Imagen.
				******
I should probably also mention that one of the first problems we
encountered with postscript on our Imagens, had to do with
"invalidaccess" error messages not related to the above dictionary
problems.  Imagen already had a fix for this, which involves downloading
two files to your hard disk, "2020.ps" and "startup.ps", which change
some systemdict parameters ... related to memory allocation, I believe.
If you have an Imagen, plan on doing much future postscript work,
and haven't yet applied this fix, you can get it by calling Imagen or
e-mailing me.
-- 
--------
Ed Arnold * NCAR (Nat'l Center for Atmospheric Research) * Mesa Lab
PO Box 3000 * Boulder, CO  80307-3000 * 303-497-1253(w) * 303-494-6949(h)
era at ncar.ucar.edu (128.117.64.4) * {ames,gatech,noao,...}!ncar!era