Scsi Bus Explanation (Scsi-A And Scsi-B) In; Configuration Table; Scsi Address Id Assignments - Digital Equipment VAXstation 3100 Maintenance Manual

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Utilities 67
devices should always be 0 as shown. Figure 3-4 shows the status codes that
contain the sizes of the drives.
STRG-1 7177.0001
00000000 00000000 00000960 00000000
~
T..
L..::~ ::: ..
o< block• (Bax) on
RX23 media diskette 00000960
Figure 3-4 STRG-1 Lines In the Configuration Table
3.1.4 SCSI Bus Explanation (SCSI-A and SCSl-B) In
Configuration Table
The SCSI bus device displays eight 8-digit numbers as shown in Figure 3-S.
Each of the 8-digit numbers contain the status of a device at a particular SCSI
address on the SCSI bus. Up to six devices can be connected to each SCSI
bus.
Figure 3-5 shows the address ID locations for the six possible drives on a
SCSI bus.
SCSI-B 3939.0001
00000001 00000001 00000001 00000001 05000001 01000000 FFFFFF03 FFFFFFOS
11111111
ID 0 ID l ID 2
RZSS RZSS RZ23
exp box exp box drive
ID 3
RZ23
drive
ID 4 ID 5 ID 6 ID 7
RRD40 TKSO SCSI-B Reserved
drive exp box controller
Figure 3-5 SCSl-B Line In the Configuration Table
3.1.4.1 SCSI Address ID Assignments
Each device on the SCSI bus, including the SCSI bus controller, has its own
address ID location. The SCSI bus controller always holds the address ID
of 6 for all buses. To determine what a drive's code indicates, see the
troubleshooting section for that drive.