Target Device | Comment |
| |
Internal disks | Up to two 3.5-inch x 1.6-inch disks |
| (9.1-Gbyte or 18-Gbyte). All internal disks |
| are UltraSCSI-compliant. |
Internal CD-ROM drive | Optional 644-Mbyte SunCD 32X speed; |
| photo CD compatible. Headphone jack with |
| volume control. CD-ROM drive is a narrow |
| SCSI device. |
Internal tape drive(s) | Refer to product guide. |
External SPARCstorage UniPack | Refer to product guide. |
External SPARCstorage SixPack | Refer to product guide. |
| |
C.1.11.3 External Cables
External UltraSCSI-compliant SCSI cables have an impedance of 90 ohm (+/- 6 ohm) and are required for UltraSCSI interface. Sun's implementation of UltraSCSI requires that the total SCSI bus length be limited to no more than approximately 20 feet (6 meters) with up to 12 Sun compensated devices. Due to the considerably short bus length, an approximately 32-inch (0.8-meter) UltraSCSI-compliant external cable is supported (part number 530-2883) in addition to an approximate 6.5-foot (2-meter) UltraSCSI-compliant external cable (part number 530-2884).
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
270 Sun Enterprise 220R Server Service Manual ♦ January 2000, Revision A
