C–1. Scsi Bus Differences - HP J Class Owner's Manual

SCSI Bus
Differences
Transfer
Rate
Single-Ended
up to up to
5 Mbytes
per second
Fast, Wide
up to up to
20 Mbytes
per second
* Address 7 is reserved for host controller use on both buses.
A Small Computer Systems Interface (SCSI) bus is an IEEE standard
bus for connecting your workstation to internal and external devices
(SCSI devices) running at different speeds, singly or in combination.
Examples of these SCSI devices are floppy disk drives, 4-mm DDS-
format tape drives, CD-ROM drives, and Winchester hard disk drives.
There are two types of SCSI buses available with this workstation – a
single-ended SCSI bus, and a fast, wide SCSI bus. Table C–1 shows
the specification differences between these SCSI buses, and Table
C–2 shows the SCSI addresses, ID numbers, and arbitration priorities
for each.
CAUTION: Do not mix single-ended and fast, wide devices
on any one bus type. Doing this will cause a
system failure.
Table C–1. SCSI Bus Differences
Data Bus Maximum
Width Addresses*
8 bits 8 bits 8 8
16 bits 16 bits 16 16
Maximum Device
Cable Physical
Length Location
6.0 meters 6.0 meters internal and internal and
(19.6 feet) external
25 meters 25 meters internal and internal and
(82 feet) external
Controller
Embedded or
Plugable
embedded embedded
embedded embedded
C-3