HP Visualize J5000 hp Visualize J5000, J7000 workstations service handbook (a4 - Page 195

SCSI Connections SCSI Bus Differences SCSI Bus Differences A SCSI (Small Computer Systems Interface) bus is an IEEE standard bus for connecting a workstation to internal and external SCSI devices running at different speeds. There may be one device connected to the external SCSI port, or several SCSI devices may be daisy-chained together and connected to the external SCSI port. Examples of these SCSI devices are 4 mm DDS-format tape drives, CD drives, and hard disk drives. There are two types of SCSI buses available with the J5000 and J7000 workstation: a Narrow Single-Ended SCSI-2 bus (NSE), and an Ultra2 Wide Low Voltage Differential SCSI bus (LVD). The following table shows the specification differences between these two SCSI buses. CAUTION Do not connect NSE SCSI devices to the LVD SCSI connector, or vice versa, because damage may occur. Currently Hewlett-Packard does not support mixing NSE and LVD devices on the same SCSI bus. Table C-1. SCSI Bus Differences SCSI Type Transfer Rate NSE LVD Up to 20 MB/sec Up to 80 MB/sec Data Bus Width 8 bits 16 bits Maximum Addresses1 Maximum Cable Length Device Physical Location2 0 through 6 3.0 meters Internal and (9.84 feet) external 0 through 6; 12 meters Internal and 8 through 15 (39.37 feet) external 1 Address 7 is reserved for host controller use on all buses. 2 This information is specific to the HP VISUALIZE J5000 and J7000 workstations. Appendix C 191