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From: pochron@cat27.cs.wisc.edu (David Pochron)
Newsgroups: comp.sys.amiga.tech,comp.sys.amiga
Subject: Re: Blitter, AmigaDOS and Multitasking
Message-ID: <5244@daffy.cs.wisc.edu>
Date: 19 Oct 90 20:58:58 GMT
References: <2354@gould.doc.ic.ac.uk>
Sender: news@daffy.cs.wisc.edu
Organization: U of Wisconsin CS Dept
Lines: 21

Your problem appears quite simple - you are "owning" the blitter during
disk read/writes, and the trackdisk.device needs the blitter to decode the
data on the disk!

You should never hog the blitter for the entire run of a
program - do all your blitter calls into one part of the code, and surround
them by Own/Disown() blitter calls.  My Ultima shader/scroller routine owns
the blitter, draws all the screen graphics with the blitter, then disowns
it.   This is the only proper way to program the blitter without being "rude"
to the system.

One other thing: make sure that you ALWAYS wait for the blitter activity to
be done, even if you are using "blitter nasty" mode - since most asynchronous
CPU cards continue to run even with "blitter nasty" turned on!
(I know -- I found out the hard way!)

--
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David M. Pochron	    |  from Rescue Rangers, _A Fly in the Ointment_
pochron@garfield.cs.wisc.edu|  Gadget to Dale:  "Keep the hands off the body!"
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