Path: utzoo!attcan!utgpu!utstat!jarvis.csri.toronto.edu!rutgers!apple!motcsd!xdos!doug
From: doug@xdos.UUCP (Doug Merritt)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Blitter Operation
Message-ID: <328@xdos.UUCP>
Date: 24 May 89 16:46:58 GMT
References: <8905132203.AA27784@postgres.Berkeley.EDU> <17209@usc.edu> <6542@ardent.UUCP> <3854@sugar.hackercorp.com>
Reply-To: doug@xdos.UUCP (Doug Merritt)
Organization: Hunter Systems, Mountain View CA (Silicon Valley)
Lines: 30

In article <3854@sugar.hackercorp.com> karl@sugar.hackercorp.com (Karl Lehenbauer) writes:
>In article <6542@ardent.UUCP>, rap@rap.ardent.com (Rob Peck) writes:
>> As I remember it, the blitter is quite capable of using EVERY cycle.
>> It only takes a back seat if it senses that some other DMA is pending.

The mode where the blitter takes *all* of the 68K cycles is the one called
BLITTER_NASTY (I guess the first time around, all of us were waiting for
someone else to say so).

It is not the blitter's usual mode, simply because it *is* unfriendly.

>Could this explain why my SMUS player "stutter-plays" anytime floppy
>activity is going on, but not during hard disk activity?  That the

I know that some hard disk controllers/drivers use BLITTER_NASTY and
others don't, depending on the manufacturer. I don't recall whether
the floppy does (I can't seem to find my Hardware Reference manual),
but I wouldn't think so because it seems like it would be slow enough
not to need it. But I could be wrong.

I suggest you try upping the SMUS task priority; that's pretty likely
to fix the problem.

Weren't you going to post this player?
	Doug
-- 
Doug Merritt		{pyramid,apple}!xdos!doug
Member, Crusaders for a Better Tomorrow		Professional Wildeyed Visionary

"Welcome to Mars; now go home!" (Seen on a bumper sticker off Phobos)