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From: oster@ucblapis.berkeley.edu (David Phillip Oster)
Newsgroups: net.micro.mac
Subject: Printerdrivers produce Postscript!
Message-ID: <497@ucbjade.BERKELEY.EDU>
Date: Mon, 31-Mar-86 13:17:50 EST
Article-I.D.: ucbjade.497
Posted: Mon Mar 31 13:17:50 1986
Date-Received: Wed, 2-Apr-86 08:34:04 EST
References: <279@daimi.UUCP> <2063@uwmacc.UUCP> <12759@ucbvax.BERKELEY.EDU>
Sender: usenet@ucbjade.BERKELEY.EDU
Reply-To: oster@ucblapis.UUCP (David Phillip Oster)
Organization: University of California, Berkeley
Lines: 19

Postscript is a programming language.  The laserPrep file that is
downloaded by the laserwriter driver defines functions so that it can send
a high level description of the quickdraw calls, rather than labourously
spelling out the details on AplleTalk each time a Quickdraw command
happens.  There is exactly one exception:  the particular smoothing
algorithm Apple uses is proprietary to Apple, so, rather than sending the
source code to the LaserWriter they use one undocumented postscript
command to define a function as pure 8000 machine codee.

[SUMEX]<INFO-MAC> has a copy of the laserprep file, with comments inserted by
Brian Reid.

My source for most of the above information is Apple itself: I went to a
seminar for developers on AppleTalk and the LaserWriter.  I have also been
to Adobe.
--- David Phillip Oster
-----------------------  ``What do you look like when you aren't visualizing?''
Arpa: oster@lapis.berkeley.edu
Uucp: ucbvax!ucblapis!oster