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From: jgh@miduet.UUCP
Newsgroups: comp.periphs,comp.sys.mac
Subject: Re: Making a Mac talk SCSI to a Sun
Message-ID: <508@gec-mi-at.co.uk>
Date: Thu, 26-Feb-87 05:17:44 EST
Article-I.D.: gec-mi-a.508
Posted: Thu Feb 26 05:17:44 1987
Date-Received: Sun, 1-Mar-87 07:40:28 EST
References: <2594@phri.UUCP> <1784@hoptoad.uucp> <540211194.20192@minster.UUCP> <1821@hoptoad.uucp>
Reply-To: jgh@gec-mi-at.co.uk (Jeremy Harris)
Distribution: world
Organization: Marconi Instruments Ltd., St. Albans, Herts, UK
Lines: 27
Xref: utgpu comp.periphs:240 comp.sys.mac:1502

In article <1821@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes:
>
>....  I don't know SCSI very well, but the disconnect-reconnect
>sequence sounds like it may be exactly what the SCSI Manager lacks.
>
The hardest thing that you probably will have to add is not the disconnect-
reconnect, which is an optional performance feature, but for at least one
end of the Sun-Mac connection to know about being a target as well as an
initiator. Most device drivers I have met only know about initiate, and
quite a few 'intelligent' host interfaces also.


In article <540211194.20192@minster.UUCP> martin@minster.UUCP (martin) writes:
>.... SCSI is rated at 10M Bits (= 1.25 M Bytes) per second....
>
I thought top-whack speed was something like 2MByte/sec (async mode,
the one most people use). Can someone with a spec tell us?  I have
at least two products here claiming 1.5M.
The usual reason for a 1.25M speed is an ESDI disk, whose raw data rate
from the HDA is 10M bits/sec. Many 5.25" drives with embedded scsi controllers
are based on the same HDA that is used for an equivalent capacity ESDI drive.

(HDA = head-disk assembly)

Jeremy.		(I don't speak for my employer)
-- 
Jeremy Harris	jgh@gec-mi-at.co.uk	...!mcvax!ukc!hrc63!miduet!jgh