A
SCSI IDs
The information in this appendix is for technical users who wish to create
custom configurations.
The small computer systems interface (SCSI) is an interface designed
for connecting disks and other peripheral devices to computer systems.
SCSI is defined by an American National Standards Institute (ANSI)
standard and used by many computer and peripheral vendors throughout
the industry.
Up to eight SCSI devices can share an SCSI bus, which is a cable. All
data is sent back and forth on the cable. Each SCSI device attached to
the cable looks at all the data, but an SCSI device only takes the data
that has the proper device identification, called an SCSI ID.
SCSI ID Default Settings
You are responsible for the SCSI ID settings on your equipment. Digital
sets each SCSI device to a default setting before the equipment leaves the
factory. You may never need to change a default setting. Default settings
should only be changed when a system is configured with more than one
of a particular device.
The SCSI ID numbers are 0 through 7. The number 7 is reserved for
a device requiring the highest priority on the SCSI bus. The number 6
is reserved for the controller. The remaining six IDs (0 through 5) are
available for custom configuration.
Table A–1 lists the default SCSI settings for the InfoServer 100. The
ID numbers listed give optimal performance on most systems. However,
if you have special performance needs, you can set the ID number on
each SCSI device manually. For most applications, SCSI IDs can be set
arbitrarily as long as no two devices share the same ID.
A–1
