Computer Skills 2011-2012 Oct

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Al-Balqa University

2011-2012

Computer SkillsBy : A . Rasheed

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Computer Ski ll s Copyright 2011 A . Rasheed - A ll ri ghts reserved

A. Rasheed Page 1 of 20 Copyright 2011

Computer Skills assesses skills and knowledge in the areas of :

operating systems and computer hardware

networks and other communications systems

graphics and multimedia

word processing

spreadsheets

Databases

Presentation Tools

internet use and email programs


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Understanding the basic concepts of IT

Information Technology (IT) system concerns the processing, storage

and/or transfer of information.

Information can take many different forms such as words,

numbers, pictures, sounds or video.

IT system can consist of computers, the telecommunications

network and other programmable electronic devices.

IT is used in business, industry, government, education, health

care and in everyday home/social life.

Computers enable us to process information and perform

specific tasks much more quickly that we can often do ourselves.

IT systems are usually very flexible and can be made to perform

a wide variety of different tasks.

IT networks allow us to distribute and share information veryquickly.

Meaning of Computer

Computer is a device that manipulates data according to a set of instructions

(program). Computer can use many programs to carry out a wide range of

useful tasks.

Computer consists of two main elements: hardware and software.

1 - Hardware:

Pieces of equipment that make up a computer system.

2 - Software:

The instructions that a computer follows (from computer programs /

applications). Operating systems, office programs and games are

examples of software.

Data

(Input Units) +

Processing

(Hardware &

Software Sys)

Information

(Output units)=


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Computer Hardware:

Motherboard and CPU

Input devices

Output devices

Storage

Motherboard and CPU (processing and storage unit)

System board or main board, the motherboard is the main circuit board of a

PC. The motherboard typically contains the processor (or CPU), BIOS (basic

input/output system), memory, mass storage interfaces, serial and parallel

ports, expansion slots, and all the controllers required to communicate with

standard peripheral devices, such as the display screen, mouse, keyboard

and disk drive. Collectively, some of the chips which reside on the

motherboard are known as the motherboard's chipset.

Processor

The processor (or microprocessor) is the brain of the computer. It reads

instructions from software and tells computer what to do. The speed at which

the CPU processes information internally is measured in Hertz.

Input Units

CPU Central Processing Unit

Output Units

CU

Control Unit

ALU

Arithmetic &Logic Unit

RAM

(Random Access

Memory)

ROM

(Read

Only

Memory)

Storage Units

HDD CDROM DVD

FDD USB Flash Mem.


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System Bus

Connects the processorwith the main memory, managing transfer of data and

instructions between the two components.


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Memory:

1. RAM (Random Access Memory)

Memory available for storing data and programs currently being processed.It is automatically erased when the power is turned off.

2. ROM (Read Only Memory)

ROM is a type of memory that normally can only be read, as opposed toRAM which can be both read and written. Most commonly used to storesystem-level programs that we want to have available to the PC at alltimes. The most common example is the system BIOS program

BIOS (Basic Input/Output System) :

An integral part of the PC, the BIOS is the program a microprocessor uses to

get the computer started after you turn it on. It also manages the data flowbetween the computer's operating system and attached peripheral devices.

CD-ROM Start reading from Center CD-ROM

Floppy Disk Formatting Floppy Disk (FDD) Floppy Disk Drive

Formatting a diskPreparing the disk to be ready to receive data, in this way the disk is dividedinto tracks and sectors.


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Hard Disk Drive (HDD)

Computer performanceTwo factors mainly affect the speed of the computer, firstly the CPU, the

higherthe CPU rating than the faster the PC will run, and secondly the RAM.

Types of computer:

There are many types of computer that are used for a variety of different

needs.

First Type : Mainframe

1- Mainframe

Mainframe is a large and powerful computer that is capable of serving avast number of users as the same time. Users do not sit down in front of the

mainframe itself, they connect to it using another smaller computer (or a dumb

terminal). The terminal consists simply of a keyboard and screen to enter and

display information. The terminal does not process or store any data itself.


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2- Minicomputer

A minicomputer is a smaller, less powerful version of a mainframe. A

minicomputer is often cheaper due to its lower processing power and storage

capacity (as compared to a mainframe). However, a minicomputer is not able

to serve as many users at once. In a similar manner to the use of amainframe, users do not sit down in front of the minicomputer itself. They

connect to is using a smaller computer or dumb terminal.

Network Computer (NC)

A Network Computer (NC) is a low-cost version of the PC. NCs are designed

to connect to and be managed by a central computer (i.e., a mainframe or

minicomputer). Every time the Network Computer is switched on (booted), it

retrieves the latest version of the software it needs from the central computer.

Therefore, components used to install and upgrade software (disk drive, CD-

Rom etc) are not required.

Network Computers have less processing power and storage capacity than

PCs and less expensive.

Network Computers tend to be used in call centers, help desks and data

processing departments. One main advantage is that when software requires

an upgrade, only the central computer is updated instead of having to update

each individual machine.

Second Type : Personal Computer

A computer (most used in homes/offices) is usually known as a PC

(Personal Computer). In the 1970s and 1980s, PCs were generally called

microcomputers. Usually, only one user accesses a PC at any one time. The

user sits in front of the PC and works directly with it, rather than connecting to

it using another computer. A PC requires far less processing power and

storage than some types of computer and this helps to make the PC much

cheaper. All PCs have a similar design and are produced by a large number

of manufacturers with different specifications.


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PCs can however, vary widely in terms of performance and the sort of tasks

they are suitable for (depending on the underlying hardware and software onthe PC). PCs often run Microsoft Windows operating systems. Other types of

personal computers such as the Apple Macintosh that use a different version

of software to a PC.

A PC is often used as an intelligent terminal to connect to a mainframe or

minicomputer.

Base unit styles of a personal computer (PC) :

Tower case : A tower-style base unit (case) is slightly larger than a desktop

PC. Network servers are usually tower PCs as they provide more room

internally for extra devices.

Desktop case : A desktop-style base unit (case) is one that usually sits flat

on a desk.


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Third Type : Portable Computers (laptop, notebooks and palmtops)

Laptop computer (also often called a notebook) is a portable computer

designed to fit inside a briefcase. Laptops have most of the features and

components provided by PCs and offer the same level of flexibility in

performing a wide range of tasks. However, the size of a laptop makes it morecostly to manufacture than a PC.

Palmtop computer is a hand-held device does not have quite the same

features and components as PCs. They are used mostly as personal

organizers to store contact information, to store lists & email/internet access.

Portable computers can be carried around easily and use a Liquid Crystal

Display (LCD) and special re-chargeable. Some units can also work in

extreme conditions (cold, underwater etc).

Bit : A digit in the binary number system, the smallest piece of information

stored in a digital device system that exists in one of two values 0 or 1.

Byte : The smallest addressable unit of memory that consists of eight bits.

CPU and RAM Speed measurements

1 Hz = 1 cycle per second1 Kilohertz = 1000 cycles per second1 Megahertz = 1000 x 1000 cycles per second1 Gigahertz = 1000 x 1000 x 1000 cycles per second

Storage/folder/file measurements

1 Byte = 8 bits1 KB = 1024 Bytes1 MB = 1024 Kilobyte (1024 KB)1 GB = 1024 Megabyte (1024 MB)1 TB Terabyte = 1024 Gigabyte (1024GB)


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A . Rasheed Page 10 of 20 Copyright 2011

Machine Language

Zero & One as indicated in Bits

Byte = 8 Bits Byte = 8 Bits

(Word = 2 Byte)

High LevelLanguage

Assembly LanguageMachine Language

PRINT AMOV dx , 41hMOV ah , 2

int 21h

10111010010000010000000010110100000000101100110100100001

1101001010111001

Types of computer

By Size By Data Types

DigitalAnalogueHybridMicroMiniLarge

PortableDesktop

Laptop

NotebookPalmtop


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(Machine Language (

Assembly Language

High-Level Language

Fortran C++ Pascal

Computer Software

System Software

Applications Software

Debugger

Operating System

Compilers

Utilities

Assembler

File Mgmt Tool

Word Processing

Communications

Graphics

Databases

Games

Spreadsheets


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Network

Network consist of, more than two computers, networks are all about sharing

resources of computers, servers, printers, scanners etc. There are two

different types with which network between computers can be formed :

1- Peer to Peer networking (p2p).

A peer-to-peer network is a wireless or wired computer network that has no

server, central hub or router. All the networked PCs are equally able to act

as a network server or client.

2- Client and Server networks.

client / server model has one dedicated computer which is called server. It

is called dedicated server. All computers are connected to hub and hub is

connected to dedicated server. Server is responsible to perform according

to the request sent to it by clients.


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The computers are connecting in one of the following :

1- Bus

2- Star

3- Ring

LAN - Local Area Network

LAN is a network that connects computers and devices over a relatively short

distance in a limited geographical area such as home, school, computer

laboratory, office.

WAN (Wide Area Network)

A WAN connects LANs and over great distances, such as across the country

and around the world. Wide-area network that uses highspeed, long-distance

communications technology.

Copyright and the LawThe purchase of software does not give you the right to install it on all pcs thatyou own neither does it give you the right to lend it to your colleagues to installor make copies of.

Shareware : Computer software developed for the public domain, which canbe used or copied without infringing copyright.

Freeware : Software which is distributed free by the author.

End-user license agreement : Software license is specified the perimeters ofthe permission granted by the owner to the user.


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VirusesA virus is a program that can "infect" other programs by modifying them toinclude a, possibly evolved, copy of itself.

Virus categories as an example :Virus Description

TrojanMalicious code that hides behind a legitimate programs waiting for acertain time or a certain program to be ran to release itself

WormA worm is a virus that does not infect other programs. It makes copies ofitself, and infects additional computers (typically by making use of networkconnections) but does not attach itself to additional programs; however aworm might alter, install, or destroy files and programs

Security :Good information security measures include:1. The use of User IDs2. The use of User passwords3. Passwords are to be alphanumeric34. Passwords should not be easily detectable e.g. name of spouse5. Passwords to be changed frequently6. Data is backed up daily7. Backed up data is removed from on site

Health and Safety : A good working environment should consist of: Appropriate positioning of monitors.

Suitable adjustable chairs.

Use of a Mouse mat.

Use of a monitor filter

Lighting.


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Starting the computer

When you switch on the computer it will perform a POST (PowerOn SystemTest) this is performed in the BIOS (Basic input/output system), this generallyhas the appearance of a black background with white text scrolling on it.

The Desktop

Start Button: Lets you quickly go to functions such as programs,settings and documents

Task Bar: Displays open windows, it lets quickly switch from onewindow to another by clicking on its icon on the taskbar.

Icons: Using for easily opening the application associated with it.

Volume: decrease/increase the system loudspeaker volume.

System Clock: change the time or date settings of computer.


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Main Icons :

My Documents

My Computer

My Network

Recycle Bin

Internet Explorer

Mouse Pointers

Parts of a window


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Folder :A subdivision of the hard disk for organizing data. Folders contain files as wellas other folders (subfolders), and they expand to accommodate contentbecause they are not a fixed, physical entity. Folders exist as electronic tablesof contents.

File :

A collection of bytes stored as an individual entity on the computer's hard disk.All data and programs are stored as files with an specific file name that mustbe unique within the disk folder (directory). Files with the same name can existin separate folders.

The basic form of a filename is : root name . ext(Almost have a three character limit on extensions)

File Extension :A file type that is appended to the end of a file name. It is a suffix (separatedfrom the base file name by a dot) to the name of a computer file applied toindicate the encoding (file format) of its contents or usage.

Files Extensions Types :

Command File ( .COM )A text file containing commands to be issued to the operating system.

Executable File ( .EXE )An executable file to perform indicated tasks according to encoded

instructions. These instructions are traditionally machine code instructions fora physical CPU.

Batch File ( .BAT )batch file is a text file containing a series of commands intended to beexecuted by the command interpreter. Working in DOS " Disk OperatingSystem ".


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Types of files :

The types of files recognized by the system are either regular, directory, orspecial and are used to contain data. A file format is a particular way thatinformation is encoded for storage in a computer file.

MeaningExtensionMeaningExtension

Graphics Interchange FormatGIFWindows System File Ext.SYS

Image 24 bit graphic formatJPGWindows Commands File Ext.COM

high quality image formatTIFWindows Execute File Ext.EXE

Bitmap GraphicBMPBatch File - DOSBAT

Audio Video InterleaveAVIWindows Dynamic Link LibraryDLL

Windows Wave format sound

file

WAVWindows Compressed ArchiveCAB

Real AudioRAWindows Initialization FileINI

Real MovieRMData File Ext.DAT

Audio File Ext.MP3Windows Help FileHLP

Media File Ext.MPGWindows Temporary fileTMP

Windows Media AudioWMAHTML Hyper Text Markup

Language

HTM

Microsoft Word DocumentDOCPortable Document Format Adobe

Acrobat

PDF

plain Text FileTXTMicrosoft Postbox Outlook

Personal File

PST

Microsoft Excel SpreadsheetXLSScreen SaverSCR

Microsoft Excel TemplateXLTWindows compression formatZIP


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Start ButtonBy clicking on the Start button, will get Start Menu that has the followingshortcuts are shown :

Shutting down the ComputerThe correct procedure to shutdown a computer is Start > Shutdown thefollowing screen will appear. This screen gives you the option to :


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Using the Help Function

To use the Windows help function click Start > Help and a new window willopen.