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From: norsk@sequent.UUCP (Doug Thompson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: MFM, RLL, SCSI drives
Keywords: RLL SCSI
Message-ID: <25342@sequent.UUCP>
Date: 22 Nov 89 22:27:48 GMT
References: <286@marvin.moncam.co.uk>
Reply-To: norsk@crg2.UUCP (Doug Thompson)
Organization: Sequent Computer Systems, Inc.
Lines: 27

In article <286@marvin.moncam.co.uk> emmo@moncam.co.uk (Dave Emmerson) writes:
>
>There's been a lot of slagging-off of RLL drives, and praising of SCSI
>(and acceptance of MFM as cheap but reliable). I've just re-read the
>much vaunted Quantum PRO80S's manual to confirm my suspicions, and it's
>TRUE, section 2, page 1 of the Installation Manual for this Embedded
>SCSI drive has an entry 
>Encoding scheme		RLL 2,7
>
>Pick the bones out of that one then!
>

At the end of each target is a controller that handles the SCSI-Drive
interface. That drive interface could be anything: AT, 506, MFM, RLL, SMD
IPI, etc. SCSI itself is not a drive interface but a device interface.
And the device interface can be constructed to handle not one but upto
8 devices per target.

Its possible to have a fast SCSI bus adapter and SCSI bus, and several
types of target controllers - fast, slow, medium.
Flexibility - its great.

-- 
Douglas Thompson		UUCP: ..{tektronix,ogcvax,uunet}!sequent!norsk
Sequent Computer Systems	Phone: (503) 526-5727
15450 SW Koll Parkway	!"The scientist builds to learn;the engineer learns in
Beaverton OR 97006	!order to build."  Fred Brooks