Lesson Outcomes

After completing this lesson, learners will be able to:

Knowledge

  • Define BIOS and CMOS

  • Identify the purpose of BIOS in a computer system

Understanding

  • Explain how BIOS and CMOS function together

  • Understand the risks and considerations when updating BIOS

Application

  • Identify when a BIOS update is necessary

  • Apply safe practices when managing BIOS settings


Overview

BIOS and CMOS are essential components that support the startup and configuration of a computer system.

This lesson focuses on:

  • The role of BIOS in system booting

  • The function of CMOS in storing system settings

  • Safe practices when updating BIOS

Understanding these components is important for:

  • System configuration

  • Troubleshooting startup issues

  • Maintaining system stability


What is BIOS?

Definition

BIOS (Basic Input/Output System) is:

  • Firmware stored on a chip on the motherboard

  • Responsible for starting the computer

  • The first software that runs when a computer is powered on


Functions of BIOS

BIOS is responsible for:

  • Initialising hardware components

  • Performing system checks (POST)

  • Loading the operating system

👉 BIOS ensures that the system is ready before the OS starts.


What is CMOS?

Definition

CMOS (Complementary Metal-Oxide Semiconductor) is:

  • A small memory chip on the motherboard

  • Stores system configuration settings


Functions of CMOS

CMOS stores:

  • Date and time

  • Hardware configuration

  • BIOS settings

👉 CMOS uses a small battery to retain data when the computer is off.


BIOS and CMOS Working Together

  • BIOS uses settings stored in CMOS

  • CMOS retains configuration information

  • Together, they ensure proper system startup

👉 Without CMOS, BIOS would not retain configuration settings.


Updating BIOS

What is a BIOS Update?

  • Updating the firmware of the motherboard

  • Improves compatibility, fixes bugs, or enhances security


Important Considerations

  • BIOS updates are risky if done incorrectly

  • Not always necessary unless there is a specific need

  • Errors during updates can damage the system

👉 BIOS updates should only be performed when required. 


When to Update BIOS

  • To fix system errors

  • To support new hardware

  • To apply security patches


Importance of BIOS and CMOS

These components are important because they:

  • Enable system startup

  • Store system configurations

  • Support hardware communication

  • Ensure system stability


Key Notes

  • BIOS is firmware that starts the computer

  • CMOS stores system configuration settings

  • BIOS and CMOS work together during startup

  • BIOS updates should be done carefully

  • These components are essential for system functionality