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From: bote@csense.UUCP (John Boteler)
Newsgroups: comp.unix.xenix
Subject: Re: CDC Read Ahead Buffer
Message-ID: <306@csense.UUCP>
Date: 19 Jul 89 04:50:10 GMT
References: <7100007@adaptex>
Organization: Common Sense Computing, McLean Va
Lines: 30

From article <7100007@adaptex>, by neese@adaptex.UUCP:
> 
> The CDC Wren IV and above have read ahead capability, but it is
> turned off by default, ...
> The read ahead buffer can be enabled via the SCSI mode sense/select
> commands for these drives.  The mode page is 38H and the location in the
> page is byte 2 bit 4.  Of course the header of the page is 14 bytes
> long so the actual byte location is byte 15.  The page length is 14
> bytes.

I'm lost.

> I have writen an extensive piece of software for bit fiddling all the
> mode pages of a SCSI device.  It also includes a low level formatter.
> It does run under MS-DOS and uses menus for poking around in a SCSI
> device. 

Must these command sequences be issued each time the device is acessed?
Powered up? Only once in its life?

I am not intimately familiar with the SCSI spec., so perhaps
pointers to references or a brief discussion would clear
up much of the confusion seen here.

Thanx in advance.

-- 
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