Scsi Device Configurations - DEC AlphaServer 1000A Owner's Manual

exceed 6 meters for single-ended SCSI-2 at 5 MB per second, or 3 meters for
single-ended SCSI-2 at 10 MB per second.
When configuring a 16-bit SCSI bus (wide), up to 15 devices are allowed on
Windows NT systems, 7 devices on Digital UNIX or OpenVMS Alpha systems.
Bus length must not exceed 3 meters.
For systems running Windows NT, no more than fifteen devices can be on any
one wide SCSI-2 controller; for systems running Digital UNIX or OpenVMS
Alpha, no more than seven devices are allowed. Each device must have a unique
SCSI ID.
If you have two or more controllers on the same bus, you need to change the bus
node ID of the second controller by setting the
variable to a value different from that of the first. Whenever you change the
value of this environment variable, you must initialize the firmware with the
command.
init

SCSI Device Configurations

Storage devices can be configured in your system in three SCSI controller
configurations: single, dual, or triple. Each SCSI controller that is used represents
one or more buses. Table 6-3 describes the three general types of SCSI bus
configuration.
AlphaServer 1000A Owner's Guide
environment
pk*0_host_id
Configuring 6-25