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From: bms@bdt.UUCP (Vance Chin)
Newsgroups: comp.sys.atari.st
Subject: Re: Hard Drive Speeds
Message-ID: <113@bdt.UUCP>
Date: 16 Aug 89 02:02:53 GMT
References: <1275@blackbird.afit.af.mil> <29194@pbhya.PacBell.COM> <399@wet.UUCP> <676@opal.tubopal.UUCP> <411@wet.UUCP>
Reply-To: bms@bdt.UUCP (Vance Chin)
Organization: Berkeley Microsystems, Oakland, CA
Lines: 13

In article <411@wet.UUCP> logic@wet.UUCP (Henry Kwan) writes:
>
>I'm curious about the BMS-200 host adapter though.  They claim that it
>supports a 1.6MB/sec transfer rate but I always thought that the ST's DMA
>bus limit was 1.33MB/sec.  Or are they measuring it at the SCSI level?
>

	The Atari DMA bus will handshake at 2 Megabytes/second,  this assumes
zero turnaround time between ack's and drq's and the DMA bus. The problem is
that the DMA chip tends to modify the data at this rate ( only a slight 
problem :-) ).  The next step down is 1.6MB/sec due to the clock rates.

Vance Chin