Sun Microsystems Sun Ultra 60 Service Manual page 209

displacement connector (IDC) receptacle attached to a 80-conductor cable. In addition
to the SCSI signals, the 80-conductor cable carries diskette drive and system LED
signals to the SCSI backplane card. The IDC receptacle mates with a right-angle plug
that is mounted on the motherboard.
The 80-conductor cable attaches on the other end to the SCSI backplane card with
another IDC connector. The SCSI backplane card incorporates two SCA-2 connectors
for mounting the hard drives, a four-circuit power connector to supply 5 Vdc and 12
Vdc power to the hard drives, a 34-pin diskette drive signal connector, and a green,
right-angle LED.
A 68-conductor cable exits the SCSI backplane card, carrying 27 SCSI signals and the
Termpower to the internal CD-ROM drive (or tape drive). The SCSI backplane card
houses the CD-ROM drive connector and three SCSI bus terminators. The
Termpower is routed through the SCSI subassembly to connect to the terminators on
the SCSI backplane card in support of the multi-host configuration. Figure C–11
shows the functionality of the internal SCSI subassembly.
Figure C–11 SCSI Subassembly Functional Block Diagram
C-29
Functional Description