>>>>> "Rick" == Rick Kelly <rmk@rmkhome.rmkhome.com> writes:

>> When you plug it in, you should be able to repeat the command and
>> get:

>> Brand INC-5411 4mm helical scan: sense key(0x6)= unit attention
>> residual= 0 retries= 0 file no= 0 block no= 0

>> If the device is not responding, retry it N times and then mark the
>> device as gone.  If the device comes back, mark it as present and
>> keep going.

Rick> This is, at least partly, a hardware design problem.  I know
Rick> that you can do this on the RS6000 and perhaps a few others, but
Rick> usually the SCSI bus hardware on most systems will react to this
Rick> by wedging.

	Which machines like the RS6000 deal with by resetting the bus.
You just need to keep enough state to be able to reset your bus, and
restart the needed commands.

	As an extreme example, our VAX/VMS machine will wait happily
for it's swap drive to return ... and even run processes that will run
until it is returned.

Dave.

-- 
----------------------------------------------------------------------------
|David Gilbert, PCI, Richmond Hill, Ontario.  | Two things can only be     |
|Mail:      dgilbert@jaywon.pci.on.ca         |  equal if and only if they |
|http://www.pci.on.ca/~dgilbert               |   are precisely opposite.  |
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