more from the 9-Aug-99 LangaList
"CMOS, BIOS, And Other Alphabet Soup
In the "System Setup" discussion (see above) I mentioned
that it's a good idea to make note of the system BIOS
settings. The BIOS is the "Basic Input/Output System" that
controls some of the very lowest-level operations in your
computer. It's also one of the first things to start in your
PC when you turn on the power: You'll almost always see a
BIOS message on your screen: You'll usually see the BIOS
maker's name (Phoenix, American Megatrends [AMI], etc.)
along with some instruction on how to enter the BIOS setup
program.
In some BIOSes, you press F1 or F2 as the system starts; in
others you hit ESC or some other key combination. Whatever
the specifics, pressing the appropriate key(s) at boot-time
stops the PC from proceeding to a normal boot, and instead
brings you to the BIOS setup program.
It's a great idea to step through the BIOS setup pages, one
at a time, and make note of the settings when your system is
working fine so you can restore the settings should they
change in the future. I use a digital camera to take
snapshots of the BIOS setup screens, but anything--- even
plain old paper and pencil--- is fine.
The BIOS holds many settings about your system--- memory
amount and type, hard drive types, security settings, built-
in peripheral settings, power-saver settings and lots more.
The BIOS is always alive, even when your PC is turned off: A
small battery on the motherboard (usually a watch-type
"button" battery in newer systems) feeds a trickle of power
to the BIOS so it can hold its settings when your system is
powered down. Some BIOSes don't need the trickle of current
for themselves, but your on-board system clock does; the
clock and the BIOS work very closely together.
Many BIOS settings can be changed. In newer systems, a Plug-
and-Play enabled BIOS cooperates with a PnP operating system
(such as Windows) and automatically updates the BIOS
settings when you add or remove certain hardware. Less
benignly, bad crashes can sometimes scramble the BIOS
settings; and if that little battery dies (and eventually,
it will) your BIOS may "forget" its settings, requiring you
to re-enter them after you've replaced the battery.
Some settings are users-configurable, too. You can adjust
your system's hardware-level security settings, for example,
or tweak low-level power saving features or even manually
enable or disable certain peripherals for troubleshooting
purposes. More trivially, you also can adjust the
"typematic" rate of your keyboard, determine whether or not
Num Lock is enabled at boot, and so on.
Many settings can be changed at will but let your own skill
and knowledge level be your guide: Don't change things at
random or blindly because the BIOS affects how your system
performs at a very fundamental level. Clever BIOS tweaking
may make your system perform better than when it was shipped
from the factory; a bad setting can leave you with a system
that's hosed. My rule of thumb is that if I know what a BIOS
setting does, and if I have a record of what the original
setting was, it's OK to try a change.
After making a change, you reboot to see the effects. If a
setting doesn't work or makes your PC perform less well,
simply reboot, re-enter the BIOS setup program and restore
the setting to what it was before. (Your owner's manual
should have additional information on user-changeable BIOS
settings.)
By the way: Some people know the BIOS by another name: CMOS
(pronounced "see-moss"). Actually, this is an incorrect
designation--- an example of how an error can become a
permanent part of the vocabulary.
When more-or-less modern BIOSes first appeared, they were
made with a technology called "Complementary Metal Oxide
Semiconductor" and were first known as CMOS BIOSes. When
people spoke in shorthand, they sometimes truncated the
wrong half of the two-acronym phrase, using the generic
"CMOS" instead of the specific BIOS. In reality, lots of
things are made with CMOS technology, but only the BIOS is
the BIOS.
Look for the startup message from your BIOS the next time
you boot your PC and take a look at the BIOS setup program;
record what the BIOS settings are, and if you know what
you're doing, try adjusting some of the settings."
:)
mark |
