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).