TOPIC 3 COMPUTER HARDWARE 

TOPIC 3 COMPUTER HARDWARE 

CONCEPT OF COMPUTER HARDWARE 

Computer hardware: 

Refers to all physical and tangible parts of a computer system that can be seen and touched.  These components enable the computer to receive data, process it, store information, and  produce output. Hardware forms the physical foundation of a computer system. 

Computer hardware works together with software to perform tasks. Without hardware,  software cannot run, and without software, hardware cannot function meaningfully. Examples of computer hardware include keyboard, mouse, scanner, system unit, monitor,  printer, speakers, hard disk, flash disk, and memory cards. 

PRACTICAL ACTIVITY 

Students should observe a computer system and identify at least ten hardware  components. They should classify them into input, processing, storage, and output devices  and write the function of each component. 

SCENARIO QUESTIONS

Explain why computer hardware alone cannot perform tasks without software. ii. State three reasons why hardware is important in a computer system.

COMPUTER HARDWARE COMPONENTS

1. INPUT DEVICES 

Input devices are hardware components used to enter data and instructions into a  computer system. They convert user actions and real-world data into a form that the  computer can process. 

KEYBOARD 

A keyboard is an input device used to enter text, numbers, and symbols into a computer. It  consists of alphanumeric keys, function keys, numeric keypad, and control keys. It is the  most common input device. 

Example: Typing examination marks or writing a document. 

MOUSE 

A mouse is a pointing input device used to control the movement of the cursor on the  screen. It allows users to click, double-click, drag, and scroll. 

Example: Selecting icons, opening files, and drawing objects. 

SCANNER 

A scanner is an input device used to convert printed text and images into digital form. The  scanned data can be stored, edited, or shared electronically. 

Example: Scanning certificates or printed photographs. 

MICROPHONE 

A microphone is an input device used to capture sound and convert it into digital audio. It  allows voice input into the computer. 

Example: Recording speech or making online calls. 

WEBCAM 

A webcam is an input device that captures live video and images. It is commonly used for  video conferencing and online meetings. 

Example: Online classes and video chats. 

JOYSTICK 

A joystick is an input device mainly used to control movement in games and simulations.  It allows precise directional control. 

Example: Playing flight simulation games. 

TOUCHSCREEN 

A touchscreen is an input device that allows users to interact with a computer by touching  the screen directly. 

Example: Smartphones, tablets, and ATM machines. 

PRACTICAL ACTIVITY 

Students should use a keyboard and mouse to create a document and use a microphone or  webcam to record audio or video.

SCENARIO QUESTIONS

Which input devices would be suitable for online learning and why? ii. Explain problems a user would face if only one input device existed.

PROCESSING DEVICES 

Processing devices are hardware components that manipulate input data to produce  meaningful information. Processing is done inside the system unit.

1. CENTRAL PROCESSING UNIT (CPU) 

The CPU is the main processing device of the computer. It executes instructions, performs  calculations, and controls all operations of the computer system. 

Example: Calculating totals, averages, and sorting data.

2. CONTROL UNIT (CU) 

The Control Unit directs and coordinates all activities within the computer system. It  controls the flow of data between the CPU, memory, and input/output devices. Example: Managing execution of program instructions. 

3. ARITHMETIC LOGIC UNIT (ALU) 

The ALU performs arithmetic operations such as addition and subtraction, and logical  operations such as comparisons. 

Example: Comparing exam scores to determine grades.

4. REGISTERS

Registers are small, high-speed memory units inside the CPU used to store data and  instructions temporarily during processing. 

Example: Holding data currently being processed. 

PRACTICAL ACTIVITY 

Students should open a calculator program and observe how numbers are processed  instantly. 

SCENARIO QUESTIONS 

1. Why is the CPU called the brain of the computer? 
2. What role does the ALU play in decision making? 

STORAGE DEVICES 

Storage devices store data, instructions, and information for future use. They ensure data  is retained and can be retrieved when needed.

RANDOM ACCESS MEMORY (RAM) 

RAM is primary storage that temporarily stores data and programs currently in use. It is  volatile, meaning data is lost when power is off. 

Example: Open documents and running applications. 

READ ONLY MEMORY (ROM) 

ROM is primary storage that stores permanent instructions used to start the computer.  Data in ROM is not lost when power is off. 

Example: Booting instructions. 

HARD DISK DRIVE (HDD) 

A hard disk is secondary storage used to store operating systems, software, and user files  permanently. 

Example: Storing school records and videos. 

A SOLID STATE DRIVE (SSD) 

is a type of secondary storage device that stores data using flash memory instead of  spinning magnetic disks like in a Hard Disk Drive (HDD). Because it has no moving parts,  an SSD is faster, more durable, and consumes less power than an HDD. 

DIFFERENCE BETWEEN HDD AND SSD 

Feature : HDD (Hard Disk Drive) : SSD (Solid State Drive) Full Name : Hard Disk Drive : Solid State Drive Technology : Uses spinning magnetic disks. : Uses flash memory with no moving  parts 

Speed : Slower read/write speed : Much faster read/write speed Durability : Prone to mechanical failure : More durable, shock-resistant Noise : Produces noise : Silent operation Power Consumption : Higher power consumption : Lower power consumption Cost : Cheaper per GB : More expensive per GB Size & Weight : Bulkier and heavier : Compact and lightweight 

FEATURES OF SSD 

1. Faster boot-up and application loading times 
2. Improved durability and resistance to physical damage
3. Silent operation with no moving parts
4. Lower power consumption, saving battery life on laptops 
5. Compact size allows for slimmer devices 
6. Better overall system performance and responsiveness

FLASH DISK 

A flash disk is a portable storage device used to transfer and back up data. Example: Moving assignments between computers. 

MEMORY CARD 

A memory card is a small storage device used in phones, cameras, and tablets. Example: Storing photos and videos. 

PRACTICAL ACTIVITY 

Students should save files in RAM, hard disk, and flash disk and retrieve them later. 

SCENARIO QUESTIONS 

1. Why is RAM faster than secondary storage? 
2. Explain the importance of backup storage devices. 

OUTPUT DEVICES 

Output devices present processed information to users in understandable form. 

MONITOR 

A monitor displays visual output such as text, images, and videos. 

Example: Viewing documents and watching videos. 

PRINTER 

A printer produces hard copy output on paper. 

Example: Printing reports and examination papers. 

SPEAKERS 

Speakers output sound from the computer. 

Example: Playing music and audio lessons. 

PROJECTOR 

A projector displays computer output onto a large screen. 

Example: Classroom presentations. 

PRACTICAL ACTIVITY 

Students should display a document on a monitor, print it, and play audio using speakers.

SCENARIO QUESTIONS 

1. Distinguish between soft copy and hard copy output. 
2. Which output device is suitable for teaching large classes and why?