Hardware Reference
In-Depth Information
In addition to checking the splash screen or BIOS Setup, you can use a program like CPU-Z or
SIV (System Information Viewer) to report the BIOS version, date, and other information.
software.com
.
Checking the BIOS Date
One method of determining the relative age and capabilities of your motherboard ROM is to check the
date. The BIOS date is stored in virtually all PCs as an 8-byte text string at memory address FFFF5h.
The date generally indicates when the BIOS code was last updated or compiled by the motherboard
manufacturer. Knowing the date of a particular BIOS might give you some clue as to which features
might or might not be present. If you are running a 32-bit version of Windows you can use the
DEBUG command-line utility to view these addresses. DEBUG presents a prompt of its own, to
which you can enter various commands. For example, the
?
command displays help information. To
find the BIOS date, open a command prompt and execute the
DEBUG
command. Then at the DEBUG -
prompt, enter
D FFFF:5 L 8
, which instructs DEBUG to display memory at FFFF5 for a length of
8 bytes. DEBUG then displays both the hexadecimal and ASCII codes found at those addresses. When
the - prompt returns, you can enter Q to quit DEBUG and return to the command prompt.
Figure 5.4
shows how this looked when I ran it on one of my systems.
Figure 5.4. Using DEBUG to display the motherboard ROM BIOS date.
In this example, the system shows a motherboard ROM BIOS date of 03/22/05. Note that DEBUG
does not work under (and therefore is not included with) 64-bit versions of Windows. In that case you
can use free programs like CPU-Z (
www.cpuid.com
)
or SIV (
www.rh-software.com
)
to check the
BIOS version and date.
Backing Up Your BIOS
Before updating a BIOS, it is generally a good idea to have a copy of the current BIOS, just in case
there are problems with the upgrade. Normally, you would not want to downgrade a BIOS, but there
have been situations over the years where some deal-breaking bug in a new release caused problems
that required going back to the previous version.
Rather than actually making a backup, it is easiest to see if the currently running (older) version can
still be downloaded from the motherboard manufacturer. Many, if not most, motherboard
manufacturers maintain an archive of older BIOS versions that can be downloaded and installed as
necessary.
If you cannot download the currently running (older) version, then see if it is possible to save a
backup copy of the existing BIOS. To make the backup, run the BIOS upgrade program for your board
as if you were going to upgrade to the latest version, and check to see if there is an option to save the
existing BIOS to a file.
