Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!ruuinf!praxis!nico
From: nico@cs.ruu.nl (Nico Verwer)
Newsgroups: comp.sys.atari.st.tech
Subject: catch SLM DMA-calls --- How?
Keywords: emulate SLM laserprinter via printerport
Message-ID: <4832@ruuinf.cs.ruu.nl>
Date: 12 Feb 91 16:17:09 GMT
Sender: news@ruuinf.cs.ruu.nl
Lines: 29


I have a NEC SilentWriter LC-800 laserprinter.
It was cheap, but it doesn't understand postscript. All it can do is print
plain ascii (diablo emulation) and print bitmaps, apart from some exotic
features.
This is a shame, because I cannot use DTP programs now, or even print
DVI-files (the ones that are produced by TeX).

I have thought of the following:
The Atari SLM laserprinter is also not very smart. As far as I'm informed,
about all it can do is print bitmaps, which are built in memory. But there is
a lot of software which can use this capabitlity!
If only I could cath the SLM output, stick some LC-800 control codes in front
of it, and send it to the printerport. In other words: I'd like to make a
SLM-to-LC800 emulator.
This would not be too hard if the SLM were accessed via the printer port, via
the normal BIOS I/O routines. But here comes the problem: The SLM is accessed
via the DMA port, for speed.

Is there a way to catch the DMA-calls to the SLM, and redirect them to my
emulator, which drives the printerport? Of course, I still want my hard disk
to function properly.
Is there anyone out there who can give a hint on how to do this?

Thanks for any information,
--
Nico Verwer                                       | nico@cs.ruu.nl
Dept. of Computer Science, University of Utrecht  | phone: +31 30 533921
p.o. box 80.089, 3508 TB Utrecht, The Netherlands | fax:   +31 30 513791