A+ Certification Guide
Chapter 3
BIOS, CMOS, and Firmware
Bootup and Configuration Files
Chapter 4
Objectives
Understand BIOS, CMOS, and Firmware:
– Explain the motherboard’s firmware, known as the BIOS.
– Describe the relationship between the CMOS and the BIOS.
Configure the System BIOS:
– Demonstrate how to access the BIOS and modify settings—for
example, RAM, processor, and video settings.
Power-On Self-Test and Error Reporting:
– Describe the POST and audible and visible errors that the
POST reports.
BIOS Updates:
– Learn how to upgrade the BIOS through flashing.
What Is BIOS?
BIOS = Basic Input Output System
– BIOS is firmware that
• Identifies connected system devices.
– CPU
– RAM
– Keyboard
– Mouse
– CD-ROM
– Display
• Tests system devices (Power-On Self-Test)
• Initializes the system devices
Where Is BIOS Found?
–
Firmware:
•
–
Two types of memory used for BIOS firmware:
•
–
Software that comes embedded in its own memory chip.
EEPROM
– Electronically Erasable Programmable Read-Only
Memory
• EPROM
– Erasable Programmable Read-Only Memory
– Older PCs used EPROM
– Could be erased by exposure to ultraviolet light:
» Also known as “Flashing the BIOS.”
Motherboard is set up to initialize its operations using BIOS.
BIOS Locations (Look for Battery)
What Is CMOS?
CMOS = Complementary Metal Oxide Semiconductor:
– A type of random access memory (RAM).
– Memory can be lost without a power source.
– On-board battery keeps this functional.
CMOS stores settings used by BIOS:
– Boot sequence; hard drive parameters.
– BIOS/CMOS access password.
– These options are passed to the BIOS soon after
the power is turned on.
– Settings can be changed by using the CMOS editor.
BIOS Settings and Screens
Common methods to access the BIOS/CMOS editor
during bootup:
– Esc
– Del
– F1
– F2
– F10
– Ctrl+Alt+?
– Most system splash screens provide information on
which key to press.
When in doubt, consult the motherboard manual.
Alterable BIOS Settings
Sampling of more frequently used options:
– Boot sequence: hard drive, CD-ROM, USB
– Memory configuration
– CPU clock and frequency (overclocking)
– CPU memory cache
– Hardware monitor (to get status of fans in case)
– Onboard audio/modem/network
– Integrated peripherals (disable/enable)
– PS/2 mouse (disable if using USB mouse)
– USB legacy for non-Windows USB keyboard
– Serial and parallel ports
Alterable BIOS Settings
USB options for 2.0 and 3.0
Keyboard options
Plug-and-play OS
Primary VGA BIOS
AGP card speed
Serial and parallel ports
Shadowing (for video BIOS)
Boot Time Diagnostics
Power management
Virtualization
Setup/BIOS password
SATA/PATA drives
BIOS Auto-Configuration
Most preferred choice versus manual setup
Three options:
– BIOS defaults:
•
Original BIOS settings
– Setup defaults:
•
Optimized settings
– Turbo:
•
Engages overclocking when CPU is not under
stress
Sample CMOS Editor
CMOS Editor—System Information
Setting Boot Sequence
Integrated Peripherals
What are integrated peripherals?
Functions that used to be
optional but are now
considered mandatory:
• Onboard video
• Onboard audio
• Onboard network card
• HDMI port
• USB ports
• External SATA drive port
Power Management
Advanced Configuration Power Interface (ACPI):
–
–
Offers less power consumption when enabled.
Six standard setting options (S0-S5):
• S0 means no power management is in effect.
– Inputs, CPU, memory, and hard drive running.
• S1/POS (power on standby)
– CPU is off; memory is being refreshed.
– PSU is on; hard drive is off.
• S3/STR (suspend to RAM)
– Microsoft calls this standby.
– PSU is off; RAM is refreshed.
• S0, S2, S4, and S5 are not commonly used.
– Note: S4 is “hibernate;” RAM saved to disk.
Power Management
Enabling Virtualization
CPU System Clock and
Overclocking Considerations
CPU “speed” is set as a multiplier of the clock
frequency.
No adjustments are needed unless overclocking is
employed.
Should you overclock?
– Better to set BIOS to “turbo” or “extreme.”
• These allow temporary overclocking in unusual
circumstances (gaming).
– Prolonged overclocking means:
• Need bigger fan/cooling apparatus
• Better power supply (PSU)
Understanding BIOS Error Codes
Power-On Self-Test (POST):
– Codes for RAM, hard drive, and CPU failure.
– Memory, keyboard, and graphics cards are
checked.
Problems can be indicated by:
– Beep codes
– On-screen error codes:
• Text display
• Hexadecimal codes
Be sure to review this section of the book before taking
the A+ exam.
Having a Successful BIOS
Upgrade
Do you need a BIOS upgrade?
– Usually not…“If it ain’t broke, don’t fix it.”
– Issues that sometimes require a BIOS upgrade for
the system to work properly:
• New hardware, such as large SATA and
PATA/IDE hard drives, and different types of
removable-storage drives
• Faster CPUs
• New operating systems and features
• New BIOS options
Before Doing a BIOS Upgrade
Back up all important data.
Record BIOS settings or take a digital picture of them:
– Identify the current version of the BIOS software.
– Identify the exact make/model of your motherboard.
Download the BIOS update software:
– Most vendors provide an .exe file that requires
minimal effort.
Highly recommended that the PC is plugged into a
UPS:
– Power interruption during BIOS upgrade may make
the entire motherboard unusable.
When Things Go Wrong
Some newer motherboards have two BIOS chips:
– Reboot using the alternative BIOS chip if the new
BIOS upgrade fails.
Check for a flash “write protect” jumper.
Reset the flash recovery jumper:
• Video may not work during this process.
– Listen for beeps.
• Reset jumper to normal.
Obtain a new flash chip from the motherboard
manufacturer.
Chapter 3
Summary
Understand BIOS, CMOS, and Firmware:
– Explain the motherboard’s firmware, known as the BIOS.
– Describe the relationship between the CMOS and the BIOS.
Configure the System BIOS:
– Demonstrate how to access the BIOS and modify settings—for
example, RAM, processor, and video settings.
Power-On Self-Test and Error Reporting:
– Describe the POST and audible and visible errors that the POST
reports.
BIOS Updates:
– Learn how to upgrade the BIOS through a process known as
flashing.
Next Lesson: Chapter 4