Intel AN430TX Specification Update page 27

11. Revision of Section 3.1.12, USB Support
This section will be replaced in its entirety as follows:
USB LEGACY SUPPORT
USB legacy support enables USB keyboards and mice to be used even when no operating system USB
drivers are in place. By default, USB legacy support is disabled. USB legacy support is only intended to be
used in accessing BIOS Setup and installing an operating system that supports USB.
This sequence describes how USB legacy support operates in the default (disabled) mode.
1. When you power up the computer, USB legacy support is disabled.
2. POST begins.
3. USB legacy support is temporarily enabled by the BIOS. This allows you to use a USB keyboard to enter
the Setup program or the maintenance mode.
4. POST completes and disables USB legacy support (unless it was set to Enabled while in Setup).
5. The operating system loads. While the operating system is loading, USB keyboards and mice are not
recognized. After the operating system loads the USB drivers, the USB devices are recognized.
To install an operating system that supports USB, enable USB Legacy support in BIOS Setup and follow the
operating system's installation instructions. Once the operating system is installed and the USB drivers
configured, USB legacy support is no longer used. USB Legacy Support can be left enabled in BIOS Setup if
needed.
Notes on using USB legacy support:
If USB legacy support is enabled, don't mix USB and PS/2* keyboards and mice. For example, do not
use a PS/2 keyboard with a USB mouse, or a USB keyboard and a PS/2 mouse.
Do not use USB devices with an operating system that does not support USB. USB legacy is not
intended to support the use of USB devices in a non USB operating system.
USB legacy support is for keyboards and mice only. Hubs and other USB devices are not supported.
12. Addition of BIOS Beep Codes Section
The following will be added after Section 4.2. Remaining tables will be renumbered accordingly.
BIOS BEEP CODES
Whenever a recoverable error occurs during Power-On Self Test (POST), the BIOS displays an error
message describing the problem. The BIOS also issues a beep code (one long tone followed by two short
tones) during POST if the video configuration fails (no card installed or faulty) or if an external ROM module
does not properly checksum to zero.
An external ROM module (e.g video BIOS) can also issue audible errors, usually consisting of one long tone
followed by a series of short tones. For more information on the beep codes issued, check the
documentation for that external device.
AN430TX SPECIFICATION UPDATE
21