Download Introduction to Hardware and software - KEN

Introduction to Hardware and software
This handout provides you with a brief historical overview of the development of computers
from Mainframes to the Personal Computer that we are familiar with today. It then moves on
to introduce you to the basic terms that are commonly used when discussing PCs. It is
important that you understand these terms as they will be frequently referred to in the
following handouts.
Key Functions of a PC
Before looking at the components of Personal Computers (PCs), it is worth taking a few
moments to consider the key functions that are performed by a computer:
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Input – Entry of raw data; for example, typing names and addresses on a keyboard or
transmitting a picture from a digital camera.
Processing – Manipulation of the raw data to produce useful information, the key
purpose of a computer; for example, sorting or indexing the names and addresses or
adding effects to the picture.
Output – Transformation of the data into information, perhaps in a non-computerised
format; for example, printing mailing labels from a database or displaying the picture in
a brochure.
Storage – Retention of the data until it is needed; for example, filing names and
addresses in a database or archiving the picture in an online library. With a basic
understanding of these key functions, the role of each of the components of a PC
becomes much clearer.
Systems components
A PC system comprises various components that interact together; these components can
be split into two distinct categories: hardware and software.
The hardware can best be described as the physical components such as the monitor, case,
hard drive and RAM.
Software is less tangible, in that it is a programme consisting of a set of instructions that
allow the PC to perform tasks. The main classes of software are:
An Operating system is designed to control the functions of the PC and provide the user
with the ability to interact with the hardware.
Applications are programmes that are written to perform specific functions such as wordprocessing, image manipulation or e-mailing.
Device Drives are programs designed to allow the operating system to fully utilise the
abilities of a hardware device.
Hardware components
Before you continue on to the technical aspects of the course you must have a sound
knowledge of the basic components that make up a computer system. The diagram below
shows some of the common components that make up the computer system.
Monitor
Printer
System case
Modem
Mouse
Keyboard
Figure 1 common hardware components
System case - contains the components of the computer, such as the motherboard, CPU
and expansion cards. System cases design fall in to three main styles:
Desktop cases are designed to sit horizontally on a desktop. There is also a special
variety of desktop case known as low-profile or slim line case that reduces the vertical
height of the systems unit.
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Tower cases are designed to stand vertically. Mini and mid towers are short towers
designed to take up less vertical space than a full size case. Full-sized cases tend to
be used by servers, whereas the mini and mid towers tend to be used by PCs.
Note:
A server is a computer, which is used to manage network resources and provide
centralised control.
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Portable systems such as laptops or notebooks combine the system unit and
input/output devices into a single lightweight unit which allows people to use their
computers while they are away from their desks.
Desktop
Tower
Notebook
Figure 2 computer case styles
Parts of the Case
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Cover – The case has a cover which is removed by either undoing the screws at the
back, or pressing together clips that release it.
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Chassis or enclosure – The chassis is the metal frame that houses the main
components of the PC.
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Front Panel – The front panel provides access to the floppy and CD, a power on/off
switch, a reset switch, and Light Emitting Diodes (LEDs) to indicate drive operation.
The front cover can be removed but may require the case cover to be removed first in
order to access the screws or clips that secure it.
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Rear Panel – The rear panel has slots through which interface card connectors appear.
These slots should either by covered by an interface card or a metal strip known as a
blanking plate.
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Drive Bays – A drive bay is an area that is designed to accommodate drive devices
such as Hard Disk Drive (HDD), floppy drive or CD ROM/DVD. An ATX Mini Tower
system case commonly has two drive bays which are known as the 3 ½ and 5 ¼ inch
drive bays. These dimensions relate to the width of the disk media these bays were
originally designed to accommodate and not the width of the bays themselves.
The 3 ½ inch drive bay is commonly used to secure the HDDs and floppy disk drives.
While the 5 ¼ inch drive bay is used to securer devices such as a CD ROM.
Fixed storage devices - an example of a fixed storage device would be a hard disk that is
secured to the internal chassis of the system case. Hard drives are made up of a collection
of magnetic disks attached to a spindle. Hard disks are non volatile storage, which means
that the data stored on a hard disk is retained even after the power is switched off.
Figure 3 a hard disk drive
Removable media drive - Most PCs have one or more forms of removable storage devices.
Removable storage devices allow data to be stored and transferred easily. There are three
main types of removable storage devices, magnetic such as floppy disks and tape drives;
optical storage such as CDs and DVDs; and solid-state storage, such as flash memory
cards and memory sticks or keys.
Power supplies - convert the high voltage Alternating Current (AC) to the low voltage Direct
Current (DC) required by computer circuitry. The power supply in a conventional desktop
system is designed to convert the 240-volt AC current into 3.3v, 5v and 12v DC current.
Figure 4 Power Supply Unit
The motherboard - is a printed circuit board which contains the main structures which make
up a system. The Diagram below shows a typical layout of an ATX motherboard.
Parallel Port
PCI Slots
USB
Port
PS2
Port
AGP
Slot
CPU
Socket
CNR
Slot
Power
Connector
RAM Sockets
Chipset
Battery
IDE Controllers
Floppy drive
Controller
Figure 5 typical ATX motherboard layout.
The Central Processing Unit (CPU), or processor, process data, and sends the processed
data to the appropriate data storage or output device.
Figure 6 The Central Processing Unit (CPU)
Memory - there are two main types of memory: Random Access Memory (RAM) and Read
Only Memory (ROM).
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When people talk about memory, they are usually referring to RAM. Program data and
instructions are copied from the hard drive to the RAM to allow the data to be accessed
quickly by the CPU. RAM is volatile memory; this means that data is lost when the
power is turned off.
Figure 7 Random Access Memory (RAM)
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Read only memory (ROM) is a type of memory that can only be read from and
provides permanent storage for data and instructions. An example of ROM is the Basic
Input/Output System (BIOS) which contains a pre programmed set of instructions
which are required during the boot process.
Figure 8 Basic Input/Output System (BIOS) Chip
The I/O expansion slots enable your CPU to communicate with peripheral devices. The
bus and its associated expansion slots are needed because basic systems cannot possibly
satisfy all the needs of all the people who buy them. The I/O bus enables you to add devices
to your computer to expand its capabilities. The most basic computer components, such as
sound cards and video cards, can be plugged into expansion slots.
Figure 9 an expansion card
Input devices such as the keyboard and mouse, are used to issue commands and enter
information into your PC. These are not the only devices that may be used to input data;
other devices such as scanners, microphones or barcode scanners are commonly used.
Output devices such as monitors, printers and speakers are commonly used with PCs.
Output devices are capable of representing information that has been generated within the
computer in a format that humans can understand.
At this point it is advisable for you to complete Lab 1.1 Identifying Components of a
Computer System
Summary
This module you have dealt with the basic concepts of hardware and software. It is important
that you have a sound knowledge of these basic concepts as you will be dealing with them in
more detail later on in the course.
Lab 1.1 Identifying the Components of a Computer System
Objectives
Upon completion of this lab you will be able to identify the various components that make up
a computer system.
Equipment
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A computer system.
Introduction
The ability to identify the components that are used as part of a computer system provides
you with the basic knowledge required to enable you to understand the concepts and
theories introduced later in the course.
Task 1
In this task you are going to determine the components that make up your computer system.

Look at your systems case; identify the style of case that you are using as part of your
system? (Enter the details in the space provided below.)
 What types of output devices are attached to your computer system? (Enter the
details below)

Identify the additional components that make up your system? (Enter the details
below)
Summary
In this Lab you have identified the basic components of a computer system.