Sun Microsystems 220R manual Hardware Configuration

You must include the Sun Enterprise 220R server internal bus length of 2.952 feet (0.9 meter) in your bus length calculations.

For fast/wide performance on the external SCSI bus, the maximum Sun-supported SCSI bus length for daisy-chained SCSI devices is 6 meters (19.7 feet), including the Sun Enterprise 220R internal bus length.

UltraSCSI devices can be mixed with non-UltraSCSI devices on the same bus. The UltraSCSI devices will still operate at UltraSCSI speeds (40 Mbytes/sec), provided that the rules for UltraSCSI cabling, bus length, termination, and target devices are followed.

If all external SCSI devices use 68-pin connectors, connect all non-Sun devices to the system first and connect a Sun autoterminating device to the end the chain.

If external mass storage devices consist of 68-pin devices and 50-pin devices, connect the Sun 68-pin devices to the system first and terminate the chain with a 50-pin device and its terminator. The 68-pin device connected to the 68-50 pin adapter cable must be autoterminating in order to terminate the high-order bits.

If you install an internal tape drive into the system, you should assign it target address 4 or 5. If you install an internal CD-ROM into the system, you should assign it target address 6. If these drives have been factory-installed, they are configured with the correct addresses for the system.

The removable media SCSI cable provides the termination for the internal SCSI bus.

Chapter 4 Hardware Configuration 87