23
56H5 / 56H1
4-4 WHAT IS CMOS
• CMOS is a special kind of memory maintained by a battery after you
turn your computer off. The BIOS uses CMOS to store the settings you
selected in SETUP. The CMOS also maintains the intermal clock. Every
time you turn on your computer, the BIOS looks in CMOS for the set-
tings you selected and configures your computer accordingly. If the bat-
tery charge runs too low, the CMOS content will be lost and POST will
issue a “CMOS invalid” or “CMOS checksum invalid” message. If this
happens, you may have to replace the battery. After the battery is
replaced, the proper settings will need to be stored in SETUP.
4-5 WHAT IS POST
• POST is an acronym for Power On Self Test. It is a traditional name for
the routines that the BIOS uses to test and initializes the devices on your
system when the PC is powered on. Its meanings has grown to include
anything the BIOS does before the operating system is started.
Each of POST routines is assigned a POST code, an unique number
which is sent to I/O port 080h before the routine is executed.
4-6 UPDATE THE BIOS
•
AWDFLASH.EXE
is a Flash EPROM Programming utility that updates
the BIOS by uploading a new BIOS file to the programmable flash ROM
on the motherboard. This file only works in DOS mode. To determine the
BIOS version, check the release date displayed on the top of your screen
during bootup. Newer dates represents a newer BIOS file.
4-6.1 BEFORE UPDATE THE BIOS
• It is recommended that you save a copy of the original motherboard
BIOS along with a Flash EPROM Programming Utility (AWDFLASH.
EXE) to a bootable floppy disk in case you need to reinstall the BIOS
later.
4-6.2 UPDATE YOUR BIOS
1. Specify
FLOPPY
as the first device in the bootup sequence from the
BIOS setup.
2. Put a empty 1.44” floppy disk into the floppy drive A:\.
3. Type
FORMAT A:\ /S
at the DOS prompt to create a bootable
system floppy disk.
4. Put the Supplier CD into the CD-ROM drive, assuming that D:\ is