Abit SL6 User Manual page 33

BIOS Setup 3-3
Computer Knowledge: CMOS Data
Maybe you have heard somebody saying that his or her CMOS DATA was lost. What is
the CMOS? Is it important? The CMOS is the memory used to store the BIOS
parameters that you have configured. This memory is passive. You can read its data, and
you can also store data in it. But this memory has to be powered by a battery in order to
avoid any loss of its data when the computer is turned off. Since you may have to
change the CMOS battery when it is out of power, and if doing so you will lose all
CMOS data, we recommend that you write down all the parameters of your hardware,
or to put a label with these parameters on your hard disk.
User's Manual