jpa@cheviot.newcastle.ac.uk (John Aspden) (10/14/87)
Apologies to anyone who received this twice - I initially cross-posted
it to comp.sys.mac and comp.laser-printers (moderated). Pnews told me that
it was sending it to the moderator of the latter, but I never saw it appear
on the former. Here goes again, to comp.sys.mac only....
At the University of Newcastle we recently (at last!) bought a few
Macs, and using the LaserWriter Driver command-F trick to generate a
Postscript file, I was able to get output on a LaserWriter attached to
a Sun using the maclaser stuff from the paintps posting by Brian Powell at
U.Texas. So far, so good.
Another recent acquisition is a TI OmniLaser 2115 printer, which has a
Postscript Interpreter at its heart. This is easily accessable from
our mainframe (Amdahl 5860 running MTS) via our local terminal-network.
I've been playing with it recently with a view to putting it into
service as our first Postscript printer available to normal users of
the Computing Service here.
I want it to be able to print Macintosh output, so I transferred the
LaserPrep file from the Sun to MTS along with a sample piece of
MacWrite generated output (TechNote #151, to be precise), sent a
concatenation of the two files to the printer, and out came...
nothing.
I then remembered a message I'd seen on the net several weeks earlier
about someone else having trouble printing Mac output on a non-Apple
PostScript printer. I passed over it at the time, and couldn't find
it, nor could I even remember which Newsgroup it had appeared in. I
*did* remember that the answer explained something along the lines
that the LaserPrep file contained the encrypted smoothing algorithms,
which used some LaserWriter-specific features, and that the fix was to
delete this stuff from the LaserPrep file. Guessing, I removed the
lines beginning "currentfile ok userdict/stretch...." down to the
second "cleartomark" - i.e. All the hex stuff and it's bracketing
commands (approx. lines 487 to 627). I then sent the new version down
followed by the postscript TN151 and lo and behold, out came Technical
Note 151 (minus the apple, but that's another story.)
Flushed with success, and crazed with ambition, I decided to try two
Mac jobs with a single LaserPrep at the start, and the whole thing
terminated by hex '04'. The first Mac job came out ok, but the second
job was printed as a mirror image!!!! (It was also upside-down).
As a controlled experiment I went back to the Sun, and sent a
PostScript job consisting of the cut-down LaserPrep followed by three
copies of PS-TN151, and from the LaserWriter came off three normal
copies of that Tech. Note. I then exported the complete PS job to MTS,
and sent it to the OmniLaser. The first and third copies came out
normally, the second copy was mirrored, so I presume that this effect
is toggled by something in the Apple end-job procedures.
Has anyone else experienced this? Did I do an incomplete hack on the
LaserPrep file? Is it a bug in the OmniLaser ROMs (it won't be the
only one - they're working on a new set)? Any workarounds/fixes?
Versions: System 4.1, Finder 5.5, LaserWriter 4.0
Brian Powell's laser-prep version 65.
TI OmniLaser 2115, PostScript Version 45.0,
firmware revision level 1.3 .
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John Aspden, University of Newcastle upon Tyne, England
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