C-3
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
Transfer
Rate Data Bus
Width Maximum
Addresses* Maximum
Cable
Length
Device
Physical
Location
Controller
Embedded or
Plugable
Single-Ended
u
p
to 8 bits 8 6.0 meters internal and embedded
up
to
5 Mbytes
per second
8
bits
8
6
.
0
meters
(19.6 feet)
internal
and
external
embedded
Fast, Wide
u
p
to 16 bits 16 25 meters internal and embedded
up
to
20 Mbytes
per second
16
bits
16
25
meters
(82 feet)
internal
and
external
embedded
* Address 7 is reserved for host controller use on both buses.
SCSI Bus Differences