Datasheet

36 Chapter 1
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Hardware
(depending on the system). Another name for this setup program is CMOS Setup. The most
common settings to adjust in CMOS include port settings (parallel, serial, USB), drive types,
boot sequence, date and time, and virus/security protections.
Accessing CMOS Setup
Your PC keeps these settings in a special memory chip called the Complementary Metallic
Oxide Semiconductor (CMOS) chip. The CMOS chip must have a constant source of power
to keep its settings. To prevent the loss of data, motherboard manufacturers include a small
battery to power the CMOS memory. On modern systems, this is a coin-style battery, about
the same diameter of a dime and about ¼ inch thick.
You can press a certain key or group of keys to access the setup program during the
power-on self-test (POST). This utility allows you to change the configuration through a
group of menus. There are many different CMOS Setup programs, depending on the BIOS
make and manufacturer, so it’s impossible to provide specifics here; instead, we’ll look at
capabilities.
Load Setup Defaults
The purpose of this setting is to configure the PC back to the default settings set by the
factory. If you make changes to your settings and the machine becomes disabled, in most
cases selecting this menu item returns the machine to a usable state. You may then try dif-
ferent settings until you achieve your desired configuration. This is an important setting to
know about before making any other changes.
Date and Time
One of the most basic things you can change in CMOS Setup is the system date and time.
You can also change this from within the operating system.
CPU Settings
In most modern systems, the BIOS detects the CPU’s type and speed automatically, so any
CPU setting in CMOS Setup is likely to be read-only.
Memory Speed/Parity
Most systems today detect the RAM amount and speed automatically. Some motherboards
can use different types of RAM, such as parity and nonparity, or different speeds, and the
CMOS Setup program may provide the opportunity to change those settings. Increasingly,
however, RAM is becoming a read-only part of CMOS Setup programs.
Power Management
The Power Management settings determine the way the PC will act after it has been idle
for certain time periods. For example, you may have choices like Minimum, Maximum,
and User Defined. The Minimum and Maximum settings control the HDD Off After, Doze
Mode, Standby Mode, and Suspend Mode settings with predefined parameters. If you select
User Defined, you must manually configure these settings to your personal preferences.
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