Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!decwrl!claris!outpost.UUCP!peirce
From: peirce@outpost.UUCP (Michael Peirce)
Newsgroups: comp.sys.mac.system
Subject: Re: Preemtive/Cooperative multitasking (Re: All about sys 7.0 <long>)
Message-ID: <0B010004.yg2h8b@outpost.UUCP>
Date: 2 Apr 91 17:23:48 GMT
Reply-To: peirce@outpost.UUCP
Organization: Peirce Software
Lines: 30
X-Mailer: uAccess - Mac Release: 1.0.3


In article <12@fleet.UUCP>, mel@fleet.UUCP (mel) writes:
> 
> Bdd
> B
> >The cure for the problem is DMA, not preemptive multitasking---the i/o
> >hardware needs to be able to operate without much cpu intervention.
> >
> >John E. Doner	doner@henri.ucsb.edu	(805)893-3941
> >Dept. Mathematics, UCSB, Santa Barbara, CA 93106
> 
> That's a good point.  And why hasn't Apple been able to get DMA working?
> The FX supposedly has the capability but no version of the operating
> system supports it EXCEPT AUX.  And rumors have it the new '040 CPU's
> won't support DMA at all. (Nor does 7.0)
> 
> What is going on at Apple in regards to DMA?  Can't someone come forward to
> explain why they keep falling down in this one area?

The problem is their SCSI software.  It's, well, not the best code
ever written by the boys (and girls) in Cupertino.

System 7 was suppose to have a new SCSI manager, but it got pushed
back until a later release.  I'm hoping it comes out soon after 7.0.

-- michael

--  Michael Peirce         --   outpost!peirce@claris.com
--  Peirce Software        --   Suite 301, 719 Hibiscus Place
--  Macintosh Programming  --   San Jose, California 95117
--           & Consulting  --   (408) 244-6554, AppleLink: PEIRCE