Specifications

Chapter 3: BIOS configuration
25
Legacy USB Support Determines whether the system supports the Legacy
Universal Serial Bus (USB).
You can select one of these:
• Enabled (default): The system supports the
Legacy USB. Select this option only if you use a USB
keyboard or mouse, and you use it with an OS that
does not have USB drivers. This option reduces system
performance due to frequent SMI interrupts (see note
below).
• Disabled: The system does not support the Legacy
USB. USB is still functional during POST; it is disabled
at INT19 (Boot Time).
Note: USB is implemented using SMIs and, if enabled,
consumes CPU, IRQ, and memory resources. Many
current OSs such as Windows 98 or Windows 2000
include built-in USB support and do not rely on BIOS
USB support.
Large Disk Access Mode Specifies whether MS-DOS systems can use hard disks up
to 8GB (1024C x 255H x 63S) without special drivers
or LBA.
If the drive fails while installing new software, change this
setting and try again.
You can select one of these:
• DOS (default): Causes the System BIOS to perform
cylinder/head translation if the drive is configured in
Setup to have more than 1024 cylinders. Select this
option if your system uses a drive larger than 528 MB
and runs DOS or MS-DOS
†
.
• Other: Select this option if your system uses a drive
larger than 528 MB and runs an OS other than DOS.
Local Bus IDE Adapter Configures the integrated local bus IDE adapter.
You can select one of these:
• Both (default)
• Disabled
• Primar y
• Secondary
Advanced Chipset Control
sub-menu
Displays a menu that you use to control chip behavior. For
more information, see Advanced Chipset Control
sub-menu on page 38.
Field Description