Specifications

CHAPTER 3

122

All About Motherboards

However, jumpers can be set to clear both passwords. Also, BIOS ﬁrmware might need

updating to solve a problem with the motherboard or to use a new motherboard feature.

If updating BIOS fails, jumpers can be set to undo the update. How to set and clear pass-

words, update BIOS, and undo a failed BIOS update are covered later in the chapter.

SETUP DATA STORED IN CMOS RAM

Computers today store most conﬁguration information in CMOS RAM, also called the real-

time clock/non-volatile RAM (RTC/NVRAM) chip, which retains the data even when the com-

puter is turned off. Motherboard manuals should contain a list of all BIOS settings (also called

CMOS settings), an explanation of their meanings, and their recommended values. When you

purchase a motherboard or a computer, be sure the manual is included as a printed booklet or

on CD. If you don’t have the manual, you can sometimes go to the motherboard manufacturer’s

Web site and download the information you need to understand the speciﬁc BIOS settings of

your computer. Table 3-5 lists some BIOS settings. Several of these are discussed in future chap-

ters. As you’re reading the table, keep in mind that the categories for BIOS settings are not uni-

versal. Each BIOS manufacturer decides which screen holds a particular setting.

acb

Figure 3-29 A 6-pin jumper group on a circuit board (a) has no jumpers set to on, (b) has a

cover parked on one pin, and (c) is conﬁgured with one jumper setting turned on

Courtesy: Course Technology/Cengage Learning

Standard Date and time Sets the system date and time (called the CMOS setup real-

time clock). Windows picks up these values when it starts up.

Keyboard Tells the system if the keyboard is installed or not; useful if

the computer is used as a print or ﬁle server and you don’t

want someone changing settings.

Hard disk type Records the size and mapping of the drive or sets to

automatically detect the HDD (discussed in Chapter 6).

Language Languages the BIOS setup screens use.

Category Setting Description

Table 3-5 BIOS settings and their purpose

Notes

Even though a computer has many CMOS chips, the term “CMOS chip” has come to mean the

one chip on the motherboard that holds the conﬁguration or setup information. If you hear someone

ask: “What does CMOS say?” or “Let’s change CMOS,” the person is talking about the conﬁguration or

setup information stored on this one CMOS chip.

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