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From: src@scuzzy.mbx.sub.org (Heiko Blume)
Newsgroups: comp.periphs.scsi,comp.unix.i386
Subject: Re: CDC WREN IV is Lying!!!
Keywords: scsi, wren
Message-ID: <1990Aug23.155444.1113@scuzzy.mbx.sub.org>
Date: 23 Aug 90 15:54:44 GMT
References: <2001@lzga.ATT.COM> <2857@bruce.cs.monash.OZ.AU> <2091@sud509.ed.ray.com>
Organization: Scuzzy Research Center (SRC)
Lines: 24

heiser@tdw201.ed.ray.com writes:
>>[using]
>>one spare 512 byte sector per track (or perhaps they meant cylinder?) results
>>in a 301MB drive.

>How does one change this so as to use the "full capacity" of the drive?
>Why is it set up this way (what is the technical reason for it)?

you have to talk to the disk using a utility like 'scsicntl.exe' from roy neese
(he's at adaptec and the utility only works with adaptec host adapters)
to issue the proper mode select commands to the drive. you can set a lot
of very interesting parameters that can affect throughput dramatically.
especially read-ahead buffers and caches are *disabled* by default in many
drives.
i have posted a long description of many of these parameters (for disk drives)
to comp.periphs.scsi some weeks ago.
i also have the above mentioned software, but i'm in germany so you'd better
look elsewhere first.

-- 
Heiko Blume c/o Diakite   blume@scuzzy.mbx.sub.org    FAX   (+49 30) 882 50 65
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