C-32 Sun Ultra 60 Service Manual August 2001
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
additionto the SCSI signals, the 80-conductor cable carries diskette drive and system
LED signals to the SCSI backplane card. The IDC receptaclemates 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-circuitpower 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
Termpoweris routed through the SCSI subassembly to connect to the terminators on
the SCSI backplane card in support of the multi-host configuration. FIGUREC-11
shows the functionality of the internal SCSI subassembly.
FIGUREC-11 SCSI Subassembly Functional Block Diagram
SCSI bus
SCA-2
Diskette
signal IDC connector
IDC receptacle connector
Test edge connector
IDC connector
Motherboard
SCSI bus terminator (3)
CD-ROM drive connector
80-conductor cable
68-pin cable
IDC connector
Drive
power
SCA-2 connector
connector (2)
Board-mounted right-angle IDC plug
68-pin external SCSI connector
SCSI
controller