Apple twentieth anniversary mac Service Manual
Before you connect a SCSI device
Before you connect a SCSI device to your Macintosh, be sure to complete the tasks explained in
this section.
this section.
Important
This section contains general instructions for attaching SCSI devices to your computer.
Be sure also to follow the specific instructions that came with your external hard disk drive or other
SCSI device when connecting the device to your Macintosh. The specific instructions that came with
the device tell how to change a device’s ID number and attach a SCSI cable or terminator to it.
SCSI device when connecting the device to your Macintosh. The specific instructions that came with
the device tell how to change a device’s ID number and attach a SCSI cable or terminator to it.
Make sure each device has a unique ID number
Each external SCSI device connected to your computer must have its own, unique ID number from 0
to 6. (Do not assign SCSI ID number 3, because it is already taken by the built-in CD-ROM drive.) The
SCSI ID number helps the computer keep track of the devices and sort out conflicts when more than
one device in the SCSI chain is communicating with the computer simultaneously.
to 6. (Do not assign SCSI ID number 3, because it is already taken by the built-in CD-ROM drive.) The
SCSI ID number helps the computer keep track of the devices and sort out conflicts when more than
one device in the SCSI chain is communicating with the computer simultaneously.
The SCSI devices can be in any physical order in the chain; it is not necessary to arrange them in
numerical order.
numerical order.
See the instructions that came with each SCSI device for information on checking and setting its SCSI
ID number.
ID number.
Important
If you use two or more devices attached to the same SCSI interface with the same ID
number, your computer will not start up properly, your equipment could malfunction, and you could
lose data as a result.
lose data as a result.
Connecting
Additional
Equipment
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