MODULE 1

KEMENTERIAN PELAJARAN MALAYSIA

Self Access Learning Module

Computer Hardware System Unit

PUSAT PERKEMBANGAN KURIKULUM

KEMENTERIAN PELAJARAN MALAYSIA

MODULE 3SYSTEM UNIT

Curriculum Development Centre

Ministry of Education Malaysia

1.Name of Module : System Unit2.Learning Outcomes: Students should be able to: a. identify the components of a system unitb. state the functions of the main components of a system unitc. state the functions of CPU, RAM, ROM and expansion slots found on the motherboard3.Knowledge and Skills

1. identify the main components in the computer system4.Module Summary:At the end of the module, students should be 1. identify the main components of a system unit and motherboard 2. state the functions of the main components of a system unit

3. state the functions of CPU, RAM, ROM and expansion slotsThis module contains 2 activities:

Activity 1 : Identify the components of a system unit Activity 2 : Identify the components of a motherboard

Note :

As you are doing this module, use a computer in the lab to identify the components in the system unit.

Activity 1 : Identifying the components of a system unita.What is system unit?

System unit is a box-like case that contains electronic components of the computer. It is sometimes called chassis. Figure 1 shows a few examples of system unit.

b.Inside view of system unit

c.Front layer of a system unit

d.Input / Output port ( I/O port )

e.Functions of the main components of a system unit

No.ComponentsFunctions

1.Input / Output port (I/O port)A port is the point at which a peripheral attaches to a system unit so that the peripheral is able to send data and receive information from the computer.

An external device, such as a keyboard, monitor, printer, mouse and microphone, that is attached by a cable to a port on the system unit.

The back of the system unit contains so many ports. Some newer personal computers also have ports on the front of the system unit.

Ports have different types of connectors. A connector joins a cable to a peripheral. One end of a cable attaches to the connector on the system unit and the other end of the cable attaches to a connector on the peripheral.

2.Power buttonTo turn the computer on

3.Reset buttonRestating the computer, instructs the computer to go through the process of shutting down, which would clear the memory and reset devices to their initialized state. It simply removes power immediately.

4.MotherboardMain circuit board of the system unit, it has some electronic components attached to it.

5.Power SupplyConverts standard electrical power into a form that, the computer can use. If a power supply is not providing the necessary power, the computer will not function properly.

6.DVD-ROM driveA device that reads DVD-ROM, audio CDs, CD-ROMSs, CD-Rs and CD-RWs.

7.CD-ROM driveA device that reads audio CDs, CD-ROMs, CD-Rs and CD-RWs.

8.DVD/CD-RW driveA combination drive that reads DVD and CD media, and writes to CD-RW media.

9.Zip driveA high-capacity disk drive that reads from and writes on a Zip disk.

10.Floppy driveA device that reads from and writes on a floppy disk

11.Hard disk driveA Type of storage device that contains one or more inflexible, circular platters that store data, instructions and information.

Activity 2 : Identify the components of a motherboarda. Components of a motherboardThe motherboard is the main circuit board of the system unit, it has some electronic components attached to it. Figure 5 shows the components of a motherboard.

Figure 6 Examples of Expansion Card and Expansion Slots

b.Functions of the components of the motherboardNo.ComponentsFunctions

1.Central Processing Unit (CPU) A Central Processing Unit or CPU is a microprocessor (processor for short). It is an integrated circuit chip that is capable of processing electronic signals. The CPU is the most important element in a computer system.

A CPU interprets instructions given by the software and carries out those instructions by processing data and controlling the rest of the computers component.

2.Random Access Memory (RAM) RAM is installed inside computers. RAM is also known as a working memory. The data in RAM can be read (retrieved) or written (stored). RAM is volatile which means the programmes and data in RAM are lost when the computer is powered off. A computer uses RAM to hold temporary instructions and data needed to complete tasks. This enables the computer's CPU (Central Processing Unit) to access instructions and data stored in the memory very quickly. RAM stores data during and after processing.

3.Read Only Memory (ROM) ROM is another type of memory permanently stored inside the computer. ROM is non-volatile. It holds the programs and data when the computer is powered off. Programmes in ROM have been pre-recorded. It can only be stored by the manufacturer; once it is done, it cannot be changed. Many complex functions, such as start up operating instructions, translators for high-level languages and operating systems are placed in ROM memory. All the contents in ROM can be accessed and read but cannot be changed.

4.Expansion Slots Expansion slots are the sockets where the circuit boards or the adapter cards can be inserted into the motherboard, such as video acceleration, sound or disk drive control.

Overview of the components of a system unit

System UnitExercise 1Label the system unit below with the words given.

Expansion CardsPower SupplyZip DriveHard Disk DriveFloppy Drive

RAMMother BoardCD/DVD DriveExpansion SlotsCPU Chip

Exercise 2Look at the diagram carefully and match them to the name of the ports in the table using numbers. Write your answers in the number column as shown in Number 1.

Exercise 3Name the component parts of the motherboard. Write your answers in the boxes given.

Exercise 4Mark T for statements that are True and F for statements that are False on the lines given.1. The processor (CPU) interprets and carries out the basic instructions that

operate a computer. 2. Computers can use only one processor at a time.

3. ROM is the main circuit board of the system unit.

4. Expansion slot is a socket on the motherboard that can hold an adapter

card.

5. RAM is non-volatile 6. The most important chip on the main circuit board is the microprocessor chip.

7. Input / output port is the point at which a peripheral is attached to a system unit so that the peripheral can send data to and receive information from

the computer.8. Reset button is to start the computer.9. A device that reads from and writes on a floppy disk is called a hard disk

drives.

10. Power supply converts standard electrical power into a form that computer can use.Exercise 5Fill in the blank with the correct name of components and functions.

No.ComponentsFunctions

1.Input/Output port (I/O port)

2.To start on computer

3.Reset button

4.Main circuit board of the system unit, which has some electronic components attached to it and others built into it.

5.Convert standard electrical power into a form that computer can use.

6.DVD-ROM drive

7.CD-ROM drive

8.This drive also allows watching a DVD or burn a CD.

9.A high-capacity disk drive that reads from and writes on a Zip disk.

10.Floppy drive

11.Type of storage device that contains one or more inflexible, circular platters that stores data, instructions and information.

Exercise 6Write the differences between primary storage RAM and ROM in the table given below.RAMROM

Reference

Cashman, S. (2006) Discovering Computers 2006. USA : Thomson Course Technology.Ibrahim Ahmad, Mohd Hafiz et al (2007) Information and Communication Technology (ICT) Based on SPM Syllabus. Selangor: Venton Publishing (M) Sdn Bhd.

NCC Education (2002) Computer Studies, Computer Ace. Sri Lanka : Computer Pioneers.IBasic Computing (2003) by TMEdu Tech (M) Sdn Bhdhttp://www.wikipedia.orghttp://images.search.yahoo.com

http://www.google.com.my

CD courseware ICT

9

Hard Disk Drive

NoLabel of the ports

1

Power port

USB port

VGA port (Monitor display)

Serial port (Modem)

PS2 port (Mouse)

Game port (Joystick)

Audio ports (speaker, headphone and microphone)

Parallel port (printer port)

PS2 port (keyboard)

Figure 5 Layout of a motherboard

CPU

Expansion Slots

Expansion Card

for RAM

Expansion slots

( look at figure 6 )

Figure 4 Back View of a System Unit

Figure 3 Front View of a System Unit

Figure 2 Internal view of a System Unit

Figure 1 Examples of System Unit

Reset button

Power port

Printer

( Parallel port )

FM reception

Telephone line out

Microphone

Serial port

Speaker

Cable TV

Network

svideo out

Monitor

Game port

Telephone line in

Mouse

USB

USB

Keyboard

Empty drive bay

Floppy disk drive

Zip drive

CD-ROM/CD-RW drive

Power button

DVD-ROM drive

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Secondary School

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