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From: jlohmeye@entec.Wichita.NCR.COM (John Lohmeyer)
Newsgroups: comp.periphs,comp.sys.atari.st
Subject: Re: ESDI questions
Summary: Where to get ESDI
Keywords: ESDI
Message-ID: <288@entec.Wichita.NCR.COM>
Date: 10 Aug 88 13:39:26 GMT
References: <168@cstw01.UUCP>
Reply-To: jlohmeye@entec.UUCP (John Lohmeyer)
Organization: NCR Corporation, Wichita, Kansas
Lines: 33

I tried to send this by e-mail, but it was returned -- sorry.

In article <168@cstw01.UUCP> Frans Meulenbroeks writes:
>I have laid my hands on an ESDI disk, which I would like to interface to
>an atari ST. However, being out-of-hardware for several years now, I'm
>having some questions:
>
>1) What exactly is ESDI? Where can I find the spec, who can recommend a
>   book or an article on this subject?

ESDI stands for Enhanced Small Device Interface.  It is a draft proposed
American National Standard.  If it is approved, it will become an ANSI 
standard.  You can buy a copy from Global Engineering Documents for $30.00.
They know it as X3.170-198X and are at 800-854-7179 or 714-261-1455. There
is also an electronic copy of the WordStar files for this document on the
SCSI Bulletin Board at 316-636-8700 (I'm the Sysop). 

>2) How does ESDI relate to ST506/ST412? and to SCSI ??
ESDI uses similar connectors to ST506, but it is a different protocol --
the data separator is in the drive, instead of the controller.  SCSI is
an intelligent interface (controller to system) instead of a device level
interface like ST506 and ESDI (drive to controller).  Embedded SCSI drives
include the controller in the drive.

>3) I know how to interface a disk with a ST506/ST412 or SCSI interface to
>   the ST. Is it doable to convert ESDI to either of these?
>   (Big wish:) Anyone by any chance aware of affordable boards to do
>   this? Magazine articles ??

Yes, you can easily go from SCSI to ESDI.  Several manufacturers make such
controllers, including NCR (800-325-SCSI).
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j.lohmeyer@Wichita.NCR.COM