IBM DU3 2104, Hardware Technical Information

Page: 18 / 36

SCSI Bus Bridge Card
Located centrally in the front of a 2104 Model DU3 or 2104 Model TU3, the SCSI bus
bridge card controls the SCSI bus configuration of the 2104. It assigns the disk drive
modules to a SCSI bus, in accordance with the setting of the SCSI bus split switch on
the switch card.
SCSI Bus Configurations
There are three valid configurations :
v
Single bus, one initiator (SCSI ID 7), 14 disk drive modules (SCSI IDs 0 through 6,
and 8 through 14)
v
Single bus, two initiators (SCSI IDs 5 and 6), 12 disk drive modules (SCSI IDs 0
through 4, and 8 through 14)
Note: In this configuration, slots 6 and 7 (SCSI ID 5 and 6) contain dummy disk
drive modules. SCSI ID 7 is reserved.
v
Dual bus, two initiators (SCSI IDs 7 (x2)), 2 groups of 7 disk drive modules (SCSI
IDs 0 through 6, and 8 through 14)
Terminator Terminator
Backplane
Terminator
Host bus adapter (HBA)
ID:7
Terminators
14 disk drive modules
Repeater
SCSI bus
bridge card
Enclosure
service
processor
Repeater
SCSI
interface
card
0 1 2 3 4 5 6 8 9 10 11 12 13 14
Figure 4. Single Bus, One Initiator, 14 Disk Drive Modules
10
2104 Models DU3 and TU3 Hardware Technical Information