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From: neil@cpd.com (Neil Gorsuch)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Sharing the SCSI bus?
Message-ID: <1989Dec12.051927.9860@cpd.com>
Date: 12 Dec 89 05:19:27 GMT
References: <1989Nov29.030959.27969@Neon.Stanford.EDU> <8252@pogo.WV.TEK.COM> <1989Dec5.165138.5192@Neon.Stanford.EDU> <1989Dec8.232535.14072@cpd.com> <1989Dec10.171249.2721@Neon.Stanford.EDU>
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Organization: Custom Product Design, Inc., Santa Ana, CA, USA
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In article <1989Dec10.171249.2721@Neon.Stanford.EDU> kaufman@Neon.Stanford.EDU (Marc T. Kaufman) writes:
>In article <1989Dec8.232535.14072@cpd.com> neil@cpd.com (Neil Gorsuch) writes:
>.1. We only see 250 Kbytes per second data transfer rates, as opposed
>.to 2.5 Mbytes per second on other machines, using our new scsi box.
>I don't know WHICH model of Mac you are using.  A Mac II can get 600 KB/sec
>in handshaking mode and 1.5 MB/sec in "blind" mode (the mode really isn't
>"blind", as there is a PAL that checks for REQ/ACK sequencing -- but there
>is an inter-character timeout of about 2 microseconds in this mode).  Yes,
>the Mac uses a CPU loop, but on 020/030 machines that goes at least as fast as
>a DMA would.

It's a MAC SE, and it really does only get 250 Kbytes per second data
transfer.  I don't know MAC's, so I might have called it the wrong
name in my original posting.

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