Subject: Re: SCSI CD changers supported?
To: None <current-users@NetBSD.ORG>
From: Christoph Badura <>
List: current-users
Date: 09/13/1996 01:52:00
Tom I Helbekkmo writes:
>OK, so I have a drive that claims to support disconnect/reconnect, but
>doesn't seem to do it.  I've tried both settings of the switch, in
>case the manual was wrong (I finally got hold of a copy), and I've
>even opened up the thing and checked that the switch itself is OK.

You know, that is odd behaviour.  If there's a switch to enable
disconnect/reconnect and the manual documents it, I'd say it is
supposed to work.

You did power-cycle the device after flipping the switch, didn't you?
Just to be sure.

>How can I find out what actually happens in there?

If you have, say, a NCR 53C8xx chip, you could hack the driver to log
disconnects off the drive.  With a BusLogic controller you would have
to resort on a SCSI bus analyser.

>What's the best
>way to figure out exactly how the drive handles IDENTIFY messages, and
>thus whether this drive (built in 1990) correctly follows SCSI-I?

Is the manual you have the "Technical Reference Manual"?  If so, you
might find something on the SCSI implementation.

Frankly, a drive built in 1990 shouldn't have any problem with
disconnect/reconnect and IDENTIFY messages.  They have been in SCSI-1
since 1986 and SCSI-2 was well on it's way in 1990.

>Anyone have a SCSI utility that can generate commands and show results?

FreeBSD's SCSI cmd?

If you have a AHA1542* controller accessible you could try Roy Neese's
scsi utilities.  Last time I checked, which was quite a while ago,
they were on in pub/adatec IIRC.  The program is
scsicmd.exe, a very useful program IMHO.

Christoph Badura

You don't need to quote my .signature.  Everyone has seen it by now.
Besides, it doesn't add anything to the current thread.