>
> > Thanks Dave for your reply. Now, are you talking about the PC being turned
> > on or the device? Normally I would turn off the device, then plug/unplug
> > it. I always thought that the need for turning off everything, plug devices
> > and then boot again was due to the need of having the SCSI devices turned
> > on BEFORE the computer, so that it sees the device/s when it boots and
> > loads drivers as appropriate.
>
> It's mildly hazardous to plug in a SCSI device if the computer (and
> the SCSI adapter) are powered on.
>
> The SCSI bus was not designed to be "hot-pluggable". When you plug
> a SCSI device into the bus, the impedance of its SCSI transceiver
> chips may cause a momentary electrical "glitch" on the bus.
> Having the SCSI device powered off may or may not prevent this...
> it depends a lot on the device, on whether it has onboard termination,
> on where it "sits" on the bus, and on the rather random order in which
> the signal and ground contacts in the connectors actually join up.
Another thing not mentioned here is that even controllers which
auto-terminate their busses may only do so once at reset. Therefore you
may need to put on a terminator after you remove the device. Not pretty.
I wonder how Mac handles this. SCSI is a standard bus, so they can't
just redefine it to suit themselves, they must address these issues in
the controller. Perhaps the external connector is designed to be treated
this way.
Of course if you want to go to a recent (2.4) kernel you could use one
of those USB<=>SCSI adaptors and be really safe, or get a PCMCIA adaptor
and matching SCSI card, which *is* designed for this.
--
-bill davidsen ([EMAIL PROTECTED])
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
