Mylex DAC960PG, Installation Manual

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SCSI Functions
2-6 DAC960PG Installation Guide
SCSI Functions
The DAC960PG manages and controls the SCSI bus arbitration between the
controller and its connected devices, and all SCSI activity of the connected
devices.
Multiple SCSI Format Support
The standard DAC960PG provides at least one, and optionally up to three,
SCSI channels for connecting disk drives or other devices, such as CD-ROM
and tape drives. With the correct cabling, these devices may be any
combination of Narrow or Wide, standard or FAST SCSI or Ultra-SCSI
formats (see Table 2-1).
Table 2-1. Supported SCSI Types
SCSI Cabling and Termination Conventions
Disk drives equipped with a SCSI interface should be connected to the
controller by means of cables that comply with standard SCSI data-rate,
pinout, and cable-length conventions (including all internal wiring). Up to
15 SCSI devices can be connected to each of the controller’s drive channels.
Disk drives at the end of each SCSI bus on a channel must be terminated.
There are no termination jumpers on the DAC960PG. If the DAC960PG is
situated at one end of the channel, it will automatically sense a termination
requirement and properly set its own termination. If the DAC960PG is
located between an internal and external SCSI bus on a channel, it will not
install termination for itself. The DAC960PG supports active termination
(alternative-2, or ALT-2).
SCSI Type Clock Rate Data Rate
Ultra-SCSI
(16-bit)
20 Mhz 40 MB/sec
Ultra-SCSI
(8-bit)
20 Mhz 20 MB/sec
Wide SCSI-2
(16-bit)
10 Mhz
5 Mhz
20 MB/sec
10 MB/sec
Narrow SCSI-2
(8-bit)
10 Mhz
5 Mhz
10 MB/sec
5 MB/sec
SCSI-1 (8-bit) 5Mhz 5MB/sec