Scsi Bus Differences - HP j6700 - Workstation Service Handbook

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 ROM drives, and hard disk drives.
There are two types of SCSI buses available with the J6700 workstation: a Narrow
Single-Ended SCSI-2 bus (SE), 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 SE SCSI devices to the LVD SCSI connector, or vice versa,
because damage may occur. Currently Hewlett-Packard does not support
mixing SE and LVD devices on the same SCSI bus.
Table B-1. SCSI Bus Differences
SCSI Type Transfer Rate
SE/LVD Up to 20 MB/sec
LVD Up to 80 MB/sec
Address 7 is reserved for host controller use on all buses.
1.
This information is specific to the HP VISUALIZE J6700 workstations.
2.
Appendix B
Data Bus Maximum
Width
Addresses
8 bits 0 through 6
16 bits 0 through 6;
8 through 15
Maximum Device
Cable Physical
1 Length
Location
3.0 meters External
(9.84 feet)
12 meters Internal
(39.37 feet)
SCSI Connections
SCSI Bus Differences
2
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