> 
> Upon startup your Mac searches it's for SCSI devices and the drivers that
> they may contain.  If it fails to find a driver after doing the SCSI search
> it loads the one that is located on the starup volume (You internal HD most
> likely).
> 
> When you startup with the ZIP disk in the ZIP drive your Mac finds the
> driver that APS put on the ZIP disk and uses that driver to control the I/O
> of the ZIP drive.  If you leave the ZIP disk out of the ZIP drive on
> startup, the driver on your startup volume loads and it controls the I/O of
> the ZIP drive.

Zip's are a little different. iomega has a control pannel (or is it an
extension) which will support the drive. They try to put only a minimal driver
on the Zip so that there's more space for your stuff. Thus if you leave the
Zip out, the iomega driver in the system folder loads and latches onto the
Zip. When you put in a cartridge, then the driver (not the one on the disk)
serves it up.

Take care,

Bill