Path: utzoo!utgpu!watserv1!watmath!att!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!wuarchive!psuvax1!rutgers!bagate!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Speed of HardFrame/2000 and Quantum Q105S (problem) (longish)
Keywords: HardFrame, Quantum
Message-ID: <16145@cbmvax.commodore.com>
Date: 29 Nov 90 16:59:00 GMT
References: <3989.659757130@lemsys.UUCP>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 20

In article <3989.659757130@lemsys.UUCP> clemon@lemsys.UUCP (Craig Lemon) writes:

>	What is wrong with this picture?  [...]

> Mask : 0x0fe

^^^^^^^

According to this, you're limiting direct DMA transfers to the word aligned
buffers in the first 256 bytes of Chip RAM.  So basically, you are never 
going to get DMA speed what that setup; even for transfers to Chip memory,
the disk will DMA into its private buffer and CPU copy to the destination.
What you really want here is a mask value of 0x00fffffe.

> Craig Lemon - Kitchener, Ontario. Amiga B2000/10--2400 bps--AmigaUUCP 1.03D

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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