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Barracuda 4 Installation Guide, Rev. E
Setting the SCSI ID jumpers
The SCSI ID for WC and DC drives is normally set over
the SCSI bus by the host system using connector
contacts 39 (ID0), 40 (ID2), 79 (ID1), and 80 (ID3).
Systems designers may, optionally, install a remote
operator panel connection to set the SCSI ID. Figure 21
illustrates the SCSI ID pins used for this purpose.
Terminating the drive
ST15150WC and ST15150DC drives do not have inter-
nal terminators or any other way of adding internal
termination to the drive. You must provide single-ended
external active termination (ANSI SCSI-2 Alternative 2)
to these drives when termination is required.
Synchronizing spindles
Spindle synchronization for WC and DC drives is nor-
mally handled on the SCSI bus by the host system using
connector contact 37 for the spindle sync reference
signal. System designers may, optionally, install a spindle
sync cable using pin 6 on the J4 connector to provide
+SSREF (see Figure 21).
WC/DC drives
