Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcrware!erik
From: erik@mcrware.UUCP (Erik Johnson)
Newsgroups: comp.sys.atari.st.tech
Subject: Blitter direct?
Message-ID: <5187@mcrware.UUCP>
Date: 4 Mar 91 21:32:00 GMT
Reply-To: erik@mcrware.UUCP (Erik Johnson)
Organization: Microware Systems Corp., Des Moines, Iowa
Lines: 21

Can I access the blitter directly for moving video data quickly?

I am currently working on an animation viewer that does its work during the
VBI.  Right now copying an image to the screen using movem's takes
approx 160,000 cycles or 1/50 sec (8Mhz), which is a little to much data to
handle in under 1/60 of a second.  I would like to make a version of my
viewer blitter-ready (make use of it, if it exists).

Can I use the blitter directly to move the data in less time?

Is it safe to even use the blitter during a vbi?

Does the blitter access memory on video or cpu access times (that is, can
both the blitter and cpu write to memory at 8 Mhz each (interleaved)?

And lastly, how do I detect the presence of the blitter?

If you could help me with any/all of my questions, it would be greatly
appreciated.

Erik R Johnson