Send Start Unit Command; Include In Bios Scan; Initiate Wide Negotiation (Aha-3980W/3985W Only) - Adaptec AHA-3980 User Manual

Leave Enable Disconnection at its default value if the channel con-
nects to two or more SCSI devices. This optimizes SCSI bus perfor-
mance. Disable disconnection if you connect an older SCSI device
that does not support disconnection.

Send Start Unit Command

This setting determines whether the channel sends the Start Unit
command to the SCSI device. Enabling this option can reduce the
load on your computer's power supply by allowing SCSI devices to
be turned on one-at-a-time when the computer boots. Otherwise, all
SCSI devices turn on at the same time.
The default setting for Send Start Unit Command is no (disabled).
Before you enable this option for a device, verify that the device sup-
ports the command. You may also need to change a switch or
jumper setting on the device to enable it to respond to the command.

Include in BIOS Scan

This setting determines whether the AHA-398x BIOS scans a specific
SCSI ID looking for a stand-alone disk device to control. If Include in
BIOS Scan is set to yes for a SCSI ID the BIOS scans the ID, and the
disk device at that ID then becomes accessible through Int 13; if the
option is set to no the BIOS does not scan the SCSI ID. The Include in
BIOS Scan setting has no effect on arrays; the AHA-398x BIOS
always scans arrays regardless of which SCSI IDs are used by the
disks in the array. The default setting for Include In BIOS Scan is yes.

Initiate Wide Negotiation (AHA-3980W/3985W only)

This setting determines whether the channel attempts 16-bit data
transfer instead of 8-bit data transfer. The default setting is yes.
When set to yes, the AHA-398x BIOS attempts 16-bit data transfer.
When set to no, the BIOS uses 8-bit data transfer unless the SCSI
device itself requests Wide negotiation. The effective data transfer
rate is doubled when 16-bit data transfer is used. For example, a
transfer rate of 10 MBytes/sec becomes 20 MBytes/sec.
Some 8-bit SCSI devices may have trouble handling Wide negotia-
tion, which may result in erratic behavior or may cause your com-
puter to hang. For these devices, set Wide Negotiation to no.
AHA-3980/3980W/3985/3985W User's Guide
Stock Number: 510810-00, Rev. D
Print Spec Number: 493479-00
Current Date: 3/1/99
Configuring the Adapter with SCSISelect
Page: 13-5
ECN Date: 3/19/96
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