#turning HD off
The SCSI ID switch is a good idea…..Remember that you'll probably have
to reset the power on the drive to get the ID change to take effect when
you change it. As for availability of those switches, I could swear I saw
rotary DIP switches at Radio Shack, but all they list is the catalog is
the std 4-8 position rocker switch type. (They'd work, but they're not as
nice as the push-button or rotary stylewhich decode the binary digits for
you.)
As for powering the drives down, I've never run into a problem with
leaving unpowered drives on the SCSI chain. The only time you might run
into a problem is if the last drive uses terminating resistor packs, and
the drive is supposed to supply terminator power. (Most newer/bigger
drives have a jumper for this.) My advice is to always use an external
terminator, and set all drives/controllers to supply terminator power to
the bus. (The latter is a recommendation by DEC for it's drives, and is
fairly commonly used.)
Good Luck,
Erik Flom