IBM Adaptec Ultra320 SCSI User Manual page 42

Introduction
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.
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.
By default, termination on an Adaptec SCSI Card 29320ALP
itself is set to Automatic (the preferred method). We recommend
that you do not change this default setting. This automatic
setting is just for the Adaptec SCSI Card 29320ALP itself; the
card cannot change the termination setting on a device.
Internal and Externa Ultra320/160 and Ultra2 SCSI LVD SCSI
buses must be terminated with an LVD terminator. This is
sometimes referred to as an LVD terminator or a Multi-Mode
terminator.
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