Specifications

AlphaServer 1000A Owner's Guide Quick Reference • 9-17
SCSI ID Settings
The system backplane can be configured with a single SCSI controller, with two
controllers, or with three controllers. For each configuration, the CDROM drive and
tape drive IDs are manually set at address 4 and 5, respectively. StorageWorks drive
IDs are set automatically by the backplane using a combination of three jumper
settings (W1, W2, W3) on the backplane. Table 9-8, Table 9-9, and Table 9-10
show these settings.
Single-Controller Configuration Jumper Options
Table 9-8 shows the SCSI IDs and jumpers installed (W1, W2, W3) for a system
with a single-controller configuration.
Table 9-8 Single-Controller Configuration Jumper Options
Device
or Slot
None W1 W2 W3 W1/J2 W1/W3 W2/W3 W1/W2/W3
Bus A
CDROM 4 4* 4 4 4 4 4 4
Tape 5 5* 5 5 5 5 5 5
Slot 0 0 0 0 8 0 8 8 8
Slot 1 1 1 1 9 1 9 9 9
Slot 2 2 2 2 10 2 10 10 10
Slot 3 3 3 3 11 3 11 11 11
Slot 4 4*
Slot 5 5*
Slot 6 6
Note:
The system does not recognize two drives with the same ID number.
Seven drives is the maximum number this configuration can recognize. A
backplane jumper cable enables you to configure all seven StorageWorks drives.
If you use slots 4 and 5, you must disable the CDROM drive and the tape drive.
If you use the CDROM drive and the tape drive, you must remove drives from
slots 4 and 5.