C-2 UltraEnterprise 6000/5000/4000 Systems Manual—November 1996
C

C.3 SCSI Cable Length

The maximum combined length for a string of SCSI cables is six meters for
non-differentialcables. For differential SCSI cables, the maximum is 25 meters.
Tocalculate the total length of a SCSI string, include external cables, internal
cables, and printed traces. TableC-3 lists measurements for Enterprise servers.

C.4 SCSI Termination

The I/O board in slot 1 of any Enterprise server must be terminated. This slot
connects to the SCSI tray through cables and a connector on the centerplane.
An I/O board in any other slot does not require termination if no devices
connect to the SCSI bus on that board.
TableC-2 DiskBoard Default SCSI Disk Drive ID Numbers
Board Slot Disk 0,1 Board Slot Disk 0,1
0 4,5 1 6,7
2 or 14* 0,1 3 or 15* 10,11
4 2,3 5 12,13
6 8,9 7 14,15
*Enterprise 6000 systems: Disk boards can only be installed in slots 14 and 15.
TableC-3 InternalSCSI Lengths (Approximate)
Location Internal Length Comments
Enterprise 6000 slot 1 3.7 meters Includes I/O board traces and cables to SCSI tray
Enterprise 5000 slot 1 3.7 meters Includes I/O board traces and cables to SCSI tray
Enterprise 4000 slot 1 1.4 meters Includes I/O board traces and cables to SCSI tray
SBus I/O board 0.43 meter Includesboard traces only
Graphics I/O board 0.43 meter Includesboard traces only
Disk board 0.64 meter Includesboard traces only