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From: keithe@tekgvs.LABS.TEK.COM (Keith Ericson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: AT vs ST506 Interfaces
Message-ID: <6117@tekgvs.LABS.TEK.COM>
Date: 11 Oct 89 00:38:33 GMT
References: <1989Oct4.234853.20690@mccc.uucp>
Reply-To: keithe@tekgvs.LABS.TEK.COM (Keith Ericson)
Distribution: na
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 22

In article <1989Oct4.234853.20690@mccc.uucp> pjh@mccc.UUCP (Pete Holsberg) writes:
>I saw an Imprimis ad recently that hawked their WREN line of hard disks.  They
>listed interfaces as ST506, AT, ESDI, and SCSI.  I'm familiar with ST506, ESDI
>and SCSI, but what do they mean by AT?  I thought that a HD with an ST506
>interface could be used with an ST506 controller on an XT or AT or even an
>AT&T 3B2/400.  How does an AT interface HD differ from an ST506 device?

Recently some drive manufacturers have realized that a large percentage
of their drives are going into a very well defined market place - the
IBM AT/Clone.  (Note: I didn't say the BUS is well defined!)

Anyway, what they've done is to essentially put what used to be the
ST506 interface (or 412 - whatever it was/is) ON THE DRIVE and
eliminate the need for "all that stuff" on an interface card.  The
connection has been reduced to just a few, if any, IC's, to buffer the
signals and maybe protect one side from a fault on the other.

At least, that's what I saw in some literature the Almac salesman
brought over recently.  I wasn't really interested so I didn't question
how multiple drives are handled, floppy/hard disk controlling, etc, etc.

kEITHe