Computer Studies - Junior Secondary 1 - System unit

System unit

Term: 2nd Term

Week: 8

Class: Junior Secondary School 1

Age: 12 years

Duration: 40 minutes of 2 periods each

Date:

Subject:      Computer studies

Topic:-       System unit

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

  1. Define System unit
  2. Enumerate the internal and external features of the system unit
  3. Explain the Central Processing Unit (CPU)

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION

TEACHER’S ACTIVITY

STUDENT’S ACTIVITY

STEP 1

INTRODUCTION

The teacher revises the previous lesson on output devices

Students pay attention

STEP 2

EXPLANATION

She defines system unit and enumerates both its internal and external features

 

Students pay attention and participates

STEP 3

DEMONSTRATION

She explains what the Central Processing Unit(CPU) is and outlines its components

Students pay attention and participate

STEP 4

NOTE TAKING

The teacher writes a summarized note on the board

The students copy the note in their books

 

NOTE

SYSTEM UNIT

The System unit also known as base unit, is the electronic circuitry housed within the computer cabinet.  It is the part of the micro computer that contains the Central Processing Unit (CPU).

 

THE INTERNAL FEATURES OF THE SYSTEM UNIT

The main body of a personal computer typically consists of a plastic/metal enclosure containing the following:

  1. Motherboard,
  2. power supply,
  3. cooling fans,
  4. internal disk drives,
  5. the memory modules and
  6. expansion cards that are plugged into the motherboard such as video and network cards.

CENTRAL PROCESSING UNIT

The CPU is a processing device found inside the system unit. It is mounted on the motherboard which is also inside the system unit. The function of a CPU is to perform the processing of data received from the input devices. The major components of the CPU are as follows:

  1. Arithmetic and Logic Unit (ALU)
  2. Control Unit
  3. Memory Unit

 

THE EXTERNAL FEATURES OF SYSTEM UNITS

The external parts of system units include:

  1. POWER BUTTON

The power button is pressed to put the system ON or OFF.  It is used to start the system from scratch.

  1. RESET BUTTON

Reset button is used to initialize the system.  The button is pressed to restart the system.

  1. THE KEY LOCK

The key lock is used to PUT ON and OFF the computer.  When the key lock is in OFF mode, the system cannot accept data. For the system to accept data, the key lock must be on.

  1. THE DRIVES

The disk drive is a part or device on which disks are loaded and run.  It enables us to use compact disks and diskettes.

A computer has more than one drive e.g. 

A: – Floppy disk drive, 

C: – Hard disk drive

D: – Compact disk drive etc.

  1. THE PORTS

These are sockets on the outside of the system unit into which you can plug a terminal or some other input/output devices. They are the areas where peripheral devices are connected to the system unit.  Ports are used to connect the keyboard, the mouse, the monitor, the printer, etc.

EVALUATION:    1. Define system unit

  1. Enumerate four internal and external features of the system unit
  2. Explain the Central Processing Unit(CPU) listing its components

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively