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Date:      Thu, 02 Jul 1998 08:12:36 -0400
From:      "Brian J. McGovern" <mcgovern@spoon.beta.com>
To:        TMM@infothuis.nl
Cc:        questions@FreeBSD.ORG
Subject:   Re: Can't install due to cdrom player used for install
Message-ID:  <199807021212.IAA20796@spoon.beta.com>

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I've had similar problems with almost every SCSI CDROM install I've ever done. 
>From my experience, it appears that almost every SCSI CD ROM will bomb itself 
out when you use the default configurations on the 2940UW, which in turn seems
to cause the bus to reset, which hoses up (or at least slows down) all the 
other devices on the chain. 

The 'fix' I've found is to go in to the Adaptec BIOS (usually CTRL-A on boot),
and crank down the settings for the affected SCSI devices. Turn off wide
negotiation, sync negotiation, and the ability to disconnect, and then crank
the SYNC speed down as low as it will go on all of your CDROM devices.

This will _usually_ give you a working configuration, although in my last 
round of installs on a Pentium II, I also had to drop the sync speeds from 
20MB/s to 16MB/s on my UW drives, because it was still causing the SCSI bus
to reset frequently.

Anyhow, once you've got your system running at a 'minimal speed', you can 
experiment with ramping up some of the other settings (such as disconnect and
SYNC negotiation) until you get the fastest, stable drive configuration you
can. I've yet to see a SCSI CD rom that survives Ultrawide negotiation being
turned on.

And this isn't just a 'FreeBSD' problem. I've locked up Win 95, NT, and DOS
so many times due to the SCSI bus going out to lunch that I almost returned
five machines before I realized what it was. Luckily, the Yamaha CD-RW drive
I ordered has a handful of LEDs on it that cycle through about half a dozen
colors and patterns to let you know whats going on. "SCSI BUS RESET" was one
of them. Had 'em popping up about every 15 seconds... It'd take about 5 seconds
to reset, 5-8 seconds for the OS to realize the drive was back and to retry,
and it'd do 3-4 seconds of I/O before it'd reset again.

You think they'd have figured out how to fix that by now :)
	-Brian

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