Disabling The Host Adapter Bios; Enabling Scsi Bus Parity; Setting Enable Disconnection; Send Start Unit Command - Adaptec AHA-2740W User Manual

AHA-2740W/2742W/2744W User's Guide

Disabling the Host Adapter BIOS

Disabling the host adapter BIOS saves you 16 KBytes of memory
address space and can also shorten boot-up time by as much as 60
seconds. See BIOS Configuration on page 3-12.
You should disable the host adapter BIOS if the peripherals on the
SCSI bus (for example, CD-ROM drives) are all controlled by device
drivers and do not require BIOS control.

Enabling SCSI Bus Parity

Parity checking is a hardware function on the host adapter to verify
the accuracy of data transfer on the SCSI bus. Data verification is a
desirable option, so SCSI Bus Parity Check is normally Enabled by
default. To use this option most effectively, be sure that it is enabled
on each SCSI device, as well as, on the host adapter. To enable/dis-
able SCSI Bus Parity Check on the host adapter, See SCSI Bus Parity
Check on page 3-9. Consult your hardware documentation for
instructions on enabling parity checking on peripherals.
Note:
The only time when you should disable parity check-
ing on the host adapter is when your system includes a SCSI
device that does not support this option. Again, consult the
hardware documentation for the device.

Setting Enable Disconnection

In the DOS environment you can increase performance slightly if
you set Enable Disconnection to no when there is only a host adapter
and a single disk device on the SCSI bus. You should set this option
to yes, however, if you have more devices on the SCSI bus. See Device
Configuration on page 3-13.

Send Start Unit Command

This option, which is supported by some SCSI devices, reduces the
load on your computer's power supply by allowing the host adapter
to powerup disk devices and other peripherals one-at-a-time when
you boot your system. Otherwise, the peripherals will all powerup
at the same time.
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