Apple Macintosh PowerBook 150 - Manual (Page 105)

Setting SCSI ID numbers
Each device in a SCSI chain must have a unique ID number between 1 and 6
so the computer can identify it properly. Your computer has the SCSI ID
number 7.
To set the ID numbers of Apple SCSI devices, follow these steps:
1 Make sure the SCSI device is turned off.
If the device is already part of a SCSI chain, make sure that all devices in the
chain are turned off, including the computer.
2 Locate the ID number indicator and switch (usually on the back panel of the SCSI
device).
3 Check the ID numbers of all the devices you want to connect.
If all the devices have unique ID numbers, you can continue with the next
section, “Checking That the SCSI Chain Is Properly Terminated.”
ID number switch
ID number indicator
WARNING Using two or more devices with the same SCSI ID number
can cause your equipment to malfunction. You could lose information
as a result.
97 Connecting Other Equipment to your PowerBook