> 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.
The only truly safe way to connect a SCSI peripheral to a standard
SCSI bus is to power down everything, connect the device, then
power everything back up. It's not very convenient, it's true.
The next-best-way is to shut down the software (or, at least,
guarantee that there is no I/O taking place on the SCSI bus in
question), connect, and then boot up or restart the software.
There are busses (e.g. PCMCIA and USB) which are designed to
support hot-plug / hot-unplug. SCSI and IDE are not, in general,
of this sort, and hot-plugging devices on these busses is not
guaranteed to be safe.
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
