Set The Scsi Switches For Each Device; Scsi Cable Lengths - DEC DECstation 5000 Model 100 Series Hardware Operator's Manual

Do not use more than 236 inches (6 meters) of cable, including
the cable inside the expansion boxes and system unit, to connect
a chain of drives. If the chain has more than 236 inches of
cable, some of the data stored on the drives may be lost.
Table 8-1 lists the length of the cables that you are using. The
table is as accurate as possible, but actual lengths may vary by
an inch or two.
Table 8-1. SCSI Cable Lengths
Cable
Internal cable for the base system SCSI connector
Expansion box internal cable
—For TK50Z tape/drive
—For RRD40 optical compact disc drive
—For TLZ04 tape drive
50-pin to 50-pin box-to-box cable
68-pin to 50-pin system-unit-to-expansion-box cable

Set the SCSI switches for each device

You can assign any ID number to a device, as long as you
Use the numbers 0 to 6. The numbers do not have to be
consecutive.
Use each number only once per chain. For example, use the
numbers 3 and 4 instead of using 4 twice.
Figure 8-3, on page 8-6, shows the SCSI switches on the drive
expansion boxes that can connect to a TURBOchannel SCSI
controller module. Table 8-2, on page 8-7, lists the SCSI ID
settings for the drive expansion boxes.
Length
52 inches
(132.1 centimeters)
14 inches
(35.6 centimeters)
6.5 inches
(16.5 centimeters)
38 inches
(96.5 centimeters)
26 inches
(66.0 centimeters)
74 inches
(188.0 centimeters)
External Storage Devices 8–5