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Unit 2 (P1, P2, M1): The Functions of Computer Hardware Components

Explain the function of computer hardware components (P1)

Internal System Unit Components


The Motherboard, also known as a Printed Circuit Board (PCB) is one of the internal components in a computer. The main function of the motherboard is to hold important components like the processor and it provides connections to other components which links everything up in the computer. For example, if there was no motherboard, then when I press a key on the keyboard, it would not register and nothing would happen.

Basic Input-Output System (BIOS)

The Basic Input-Output System (BIOS) is built into the PC, and is the first code run by the PC when it is powered on. The main function of the BIOS is to load and start an Operating system (OS). When this code is initiated, it then starts to check and verify the internal components like the CPU and HDD to see if anything is working the way it should. If something is wrong it will print out an error message on your monitor to say it’s not working correctly. When you insert a USB or CD, the BIOS starts to load the software on it to give the computer control. This process is called booting.

Power Supply Unit

The Power Supply Unit (PSU) changes Alternating Current (AC) from a wall socket to low-voltage Direct Current (DC) to operate the internal components and peripheral devices.

Fan & Heat Sink

A Heat Sink is a device that uses a fan or a peltier to keep a hot component such as a processor cool. There are two heat sink types: active and passive.

Active heat sinks utilise power and are usually a fan type or some other peltier cooling device. Sometimes these types of heat sinks are referred to as a HSF, which is short for heat sink and fan.

Passive heat sinks are 100% reliable, as they have no mechanical components. Passive heat sinks are made of an aluminium-finned radiator that dissipates heat through convection. For Passive heat sinks to work to their full capacity, it is recommended that there is a steady air flow moving across the fins.

Random-access Memory (RAM)

The Random-access Memory (RAM) is where the operating system, applications and data is kept so that they can easily be accessed by the CPU. The data on the RAM is stored on here until the computer is turned off, this is called volatile memory. When the computer turns back on, the operating system and other data is loaded on again.

Read-only Memory (ROM)

The Read-only Memory (ROM) keeps its contents even when the computer is turned off. This is also known as non-volatile. Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer.

Hard Disk Drive (HDD)

The Hard Disk Drive (HDD) is used to permanently store data, documents, computer programs and the operating system. This is used to store large amounts of data in a computer system. The HDD is different from other memory components, this is because the HDD is non-volatile memory. This means that if the computer turns off, it does not lose its data stored on there.

Central Processing Unit (CPU)

The Central Processing Unit (CPU) is the brain of the computer which carries out instructions of a computer program. The CPU sits on the motherboard. All of the other hardware components and programs installed on the system has to go through the CPU before the function can be completed. When a function is sent, the CPU gets it from the RAM and any other hardware in order to process it. The CPU then reads the instructions linked to the task before sending it back to the RAM. There’re two types of data that the CPU handles. One is the data that needs to be processed and the other is the program code connected to the data. The programming code is a list of instructions on how the data should be handled and processed.