Sun Microsystems Ultra 60 Service Manual page 232

C.1.14.4 Internal SCSI Subassembly
The internal SCSI subassembly consists of two cable assemblies and two SCSI cards.
The SCSI subassembly is attached to the motherboard using an insulation
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.
shows the functionality of the internal SCSI subassembly.
68-pin external SCSI connector
SCSI bus
FIGURE C-11
C-32 Sun Ultra 60 Service Manual • August 2001
Motherboard
SCSI
controller
Board-mounted right-angle IDC plug
SCSI Subassembly Functional Block Diagram
68-pin cable
IDC connector
CD-ROM drive connector
SCA-2 connector
SCSI bus terminator (3)
Drive
power
Diskette
signal
Test edge connector
IDC receptacle connector
FIGURE C-11
IDC connector
SCA-2
connector (2)
IDC connector
80-conductor cable