From owner-freebsd-hardware  Fri Aug 11  1:55:50 2000
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Date: Fri, 11 Aug 2000 04:53:01 -0400
From: "Gary T. Corcoran" <garycor@home.com>
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To: Francisco Reyes <fran@reyes.somos.net>
Cc: FreeBSD Hardware List <freebsd-hardware@FreeBSD.ORG>,
	Michael VanLoon <MichaelV@EDIFECS.COM>
Subject: Re: Best behaved  drives for FreeBSD?
References: <200008110751.DAA11086@sanson.reyes.somos.net>
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Francisco Reyes wrote:
> 
> On Fri, 11 Aug 2000 03:37:28 -0400, Gary T. Corcoran wrote:
> 
> >I don't think so.  My understanding is that ATA100 uses the *same*
> >cables as ATA66 - they were just able to squeeze another 33MHz of
> >performance out of them.
> 
> No.
> >From http://www.ixbt-labs.com/storage/ata-100.html
> 
> Having weighed all pro and contra, Quantum developed
> a new ATA/100 interface with additional speed, which
> allows transferring the data at 100MB/sec along the
> host-to-drive bus and hence to unload the HDD buffer
> memory. This new interface incorporates all the
> innovations made to the cables and connectors
> supporting ATA/66. Just to remind you let us say once
> again that ATA/100 interface requires the same good
> old 40-pin IDE cable used in ATA/66. However, since the
> burst transfer rates have become considerably higher,
> better protection against crosstalk and electromagnetic
> noise interference turned out necessary. For this
> particular purpose 40 additional ground lines were
> tied together and acted as shields between the lines
> that actually carried live signals back and forth. So,
> altogether the new ATA/100 cable is composed of 80
> conductors. However, the developers wanted to retain
> the conventional 40-pin connector, so that to ensure
> plug compatibility with existing drives and systems.

Huh?  You seem to be disagreeing with me, yet as I read the
above, it seems to agree with what I said: the ATA66 and
ATA100 drives use the *same* 80 conductor (40 pin) cables.
That is, ATA66 *already* added the extra 40 ground wires
to make the cable 80 conductors, and ATA100 uses the same
thing.  The above is a little misleading, in that they
(almost) imply that ATA66 uses the same cables as ATA33,
which is NOT true...  (I *do* have ATA66 cables, with 80
conductors :)

Gary


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