S1952DLU Thunder X
B-3
APPENDIX B
2. Setting Up SCSI Peripherals
Setting up SCSI peripherals before attaching them to the SCSI connectors
typically involves setting SCSI IDs and termination, mounting internal
peripherals inside your computer, and connecting power cables to each
peripheral. Since setup can vary from peripheral to peripheral, always refer to
the peripheral’s documentation for specific instructions. Below are some
guidelines for setting SCSI IDs and termination on your peripherals.
NOTE: If you refer to the peripheral’s documentation for installation
instructions, be sure to return to this document to continue with installa-
tion of the software included in the package.
Check the SCSI IDs
The motherboard SCSI connectors and each peripheral you connect to it
requires a unique SCSI ID number ranging from 0 to 15 on each channel. ID
numbers don’t have to be sequential, as long as the connector and each
peripheral has a different number for each channel.
Each SCSI channel on the motherboard is preset to ID 7 and should not be
changed. If you will be booting from a SCSI hard disk, it’s best to set the
disk’s ID at 0 or 1. Most SCSI hard disks come from the factory preset to ID 0.
The IDs for internal peripherals are usually set with jumpers; external periph-
erals are usually set with a switch on the back of the peripheral.
Terminate the Ends
To ensure reliable communication on the SCSI bus, the peripheral at the end
of each cable, or the end of the cable itself, must have a terminator installed
(or enabled). The peripherals between the ends of each cable must have the
terminator removed (or disabled).
NOTE: When connecting Ultra2 SCSI peripherals, it is important to note
that the necessary termination of the SCSI bus is done either on the end of
the cable (with a permanent terminator) or a separate terminating connec-
tor. Ultra SCSI and earlier single-ended devices had the ability to terminate
the bus directly from the device. Using an Ultra SCSI terminator on an LVD
Ultra2 SCSI bus will force the bus to single-ended mode, limiting the speed
and cable distance. For this reason be sure that you have the necessary
Ultra2 cable or terminator before installing the Ultra2 SCSI devices.
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