HP PL Class 450/500/550/600/650/700/750 User Manual page 120

Host SCSI ID
Scan Order
Removable Media
Support
CHS Mapping
Technical Information
Using the SCSI Configuration Utility
In general it is not advisable to change your host adapter ID from the
default value of 7, as this gives it the highest priority on the SCSI bus.
However, if you have two adapters sharing the same SCSI devices, you
should give one of the adapters a currently-unassigned ID to avoid
duplication of SCSI IDs.
This option lets you tell the host adapter BIOS and your device drivers to
scan the SCSI bus from low to high (0 to max) SCSI ID, or from high to
low (max to 0) SCSI ID. If you have more than one device on a SCSI bus,
changing the device order changes the drive letters which are assigned to
them by the system.This will change the boot order.
Only used when removable disk drives are installed. For more
information, refer to the User's Guide that came with you removable disk
drive.
When performing a 'low format', CHS mapping should be set to Alternate
CHS Mapping for full compatibility with other SCSI adapters. This is the
default setting.
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