C.1.11.4 Internal SCSI Subassembly

The internal SCSI subassembly consists of two cable assemblies and two SCSI cards. The SCSI subassembly is attached to the main logic board using an insulation displacement connector (IDC) receptacle attached to a 80-conductor cable. In addition to the SCSI signals, the 80-conductor cable carries system LED signals to the SCSI backplane card. The IDC receptacle mates with a right-angle plug that is mounted on the main logic board.

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, 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 one SCSI bus terminator. The Termpower is routed through the SCSI subassembly to connect to the terminator on the SCSI backplane card in support of the multi-host configuration. The following figure shows the functionality of the internal SCSi assembly.