Technical data

4
4-1
4SCSI Device Storage Module
This chapter provides a brief overview of the SCSI Device Storage
module. For more information about this device, please refer to the
XR900 Series Mass Storage Subsystem User’s Manual (available
through your local Motorola sales representative).
Overview
The SCSI Device Storage Module has room for up to four SCSI
devices. It contains four half-height peripheral bays. Two of the
bays accommodate 3 1/2-inch hard disk drives, and the other two
bays accommodate either 3 1/2-inch hard disk drives or 5 1/4-inch
removable media devices.
Backplanes
The SCSI Device Storage Module has two backplane options:
differential and single-ended. The differential backplane only
supports differential SCSI drives, and the single-ended backplane
only supports single-ended SCSI drives.
The backplane provides support for the four SCSI drives, all drive
power connections, and the SCSI signal lines for the installed
devices.
Chassis Options
The SCSI Device Storage Module has two chassis options: Original
and Extended. The Original Chassis option is compatible with and
installs on the Original style of XR chassis. The Extended Chassis
option is compatible with and installs on the Extended style of XR
chassis. Both chassis options support the differential and single-
ended backplanes.