Terminating The Scsi Bus - Adaptec 39320D User Manual

Adaptec SCSI Card 39320D User's Guide for Floppy Disks (OEM)
If you are booting your computer from a SCSI hard disk drive
■
connected to the Adaptec SCSI Card 39320D, the Boot SCSI ID
setting in the SCSISelect utility must correspond to the SCSI ID
of the device from which you are booting. By default, the Boot
SCSI ID is set to 0. We recommend that you do not change this
setting.
With the SCSISelect disk utility feature, you can confirm/view
■
which SCSI ID is assigned to each device. See
Configuring the Adaptec SCSI Card 39320D with SCSISelect
more information.

Terminating the SCSI Bus

To ensure reliable communication on the SCSI bus, the ends of the
SCSI bus must be properly terminated. This is accomplished when
the device at the end of each cable, or the end of the cable itself, has
a terminator installed (or enabled). Terminators must be removed,
or termination must be disabled, on devices between the ends of
each cable.
Since the method for terminating a SCSI device can vary widely,
refer to the device's documentation for instructions on how to
enable or disable termination. Here are some general guidelines for
termination:
Internal Ultra320/160 and Ultra2 SCSI LVD devices come from
■
the factory with termination disabled and cannot be changed.
Proper termination for these internal devices is provided by the
built-in terminator at the end of the 68-pin internal LVD SCSI
cable.
Termination on SE internal SCSI devices is usually controlled
■
by manually setting a jumper or a switch on the device, or by
physically removing or installing one or more resistor modules
on the device. For further information on device termination,
refer to the device manufacturer's documentation.
Termination on most external SCSI devices is controlled by
■
installing or removing a SCSI terminator. However, termination
on some external SCSI devices is enabled or disabled by setting
a switch on the back of the SCSI device. For further information
on device termination, refer to the device manufacturer's
documentation.
Chapter 3,
for
1-6