NAMAKWA SS ICT DEPARTMENTAL NOTES 2017 Web viewData compressor. Anti-virus programs. ... Word Star....

NAMAKWA SS ICT DEPARTMENTAL NOTES 2017

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COMPUTER STUDIES O’LEVELSENIOR ONE: TOPIC 1: INTRODUCTION TO COMPUTERS

1.1 Computers todayA computer ; is an electronic multipurpose machine which is used to in-put data, process data, store data and out-put data or retrieve information.

Characteristics of modern computers Speed: computer are quite fast in their operations in that their speed is

measured in millions instructions per second i.e. the computer is capable of processing 15 million instructions per second

Accuracy: computers are known to be accurate that they hardly make any mistake. So for computers if wrong data is fed in it then expect wrong information as the principle of GIGO

Storage: for a computer to work it must have a work area or work space where data is stored before and after processing. The space is known as memory

Diligence. Computers have the ability to perform the same work repeatedly without getting bored and each time they produce consistent results without any divergence from the previous results

Artificial intelligence: computers are artificially intelligent as they can respond to requests given to them and provide solutions. This is done by its programmability ie can be taught to make decisions and functions accordingly

Automation: computers also work automatically; they do not need to be reminded to perform any of the instructions when executing a programmed routine. E.g. making a routine daily alarm at specific times

Versatility: computers can be able to do many tasks at the same time e.g. playing music, typing a document and browsing internet at the same time

TERMINOLOGIES IN COMPUTER STUDIESData: means the raw material that is fed into the computer to be processedThis can also be defined as the unprocessed information.Information: this is processed data or data that has been turned into a meaningful form.





Hard ware: This refers to physical tangible parts of a computer.Soft ware: This is parts of a computer or instructions a computer must follow to accomplish a given task.Icons: Small pictures used to represent programs files, folders, short cuts, hard ware or soft ware features.File: Data that is stored in memory and named so that it can be easily retrieved for useWindow: A frame that may contain icons or text or picturesDesktop: The first screen that you see once the computer is fully functioningBooting: This means to start or restart a computer.Bug: This is an error in a program that prevent the computer to work properly causing it to freeze so that nothing works.Debug: correcting errors in a programPeripheral devices: These are the devices which can be connected to the computer other than the basic ones. Examples of peripheral devices are printers, scanners, loudspeakers, joy sticks for games.

REASONS FOR STUDYING COMPUTERS

To acquire general knowledge and skills in the use of computers and related technologies

To use the acquired knowledge in computer studies to enhance learning other subjects

To understand important issues of a technology based society and exhibit them using computers

To acquire knowledge as a foundation for further studies in computer technology

To use a variety of computer technologies to assess, analyze and interpret information

Jobs Passing exams

DATA AND INFORMATION

1. DATA





Data is defined as raw facts and figures that have less meaning to the end user.These are basic facts of any event in life such as costs, prices, date time etc (unorganized facts) e.g. a list of students in a school irrespective of their classes, sex or age.

Examples of raw data include;

1. Student’s marks2. Employee salary and wedges.

2. INFORMATION

Information is a processed data which is meaning full to the end. Information helps the user to make decision

Examples of information

1. A students report2. Payroll for employees

Qualities of good information It should be complete It should be clear Should be available whenever needed It should be Relevant to its purpose

Information processing cycleThe sequence of events in processing information. The cycle illustrates the stage through which data is transformed into information.

They are 4 stages of the information processing cycle:• Input

• Processing• Storage• Output

WWW.bedesoft.org email [email protected] 0787277091 PROCESSING

STORAGE

OUTPUT

INPUT




1.2 EVOLUTION OF COMPUTERS (ROOTS OF A COMPUTER) Origin of counting Mechanical era Electro-mechanical era Electronic era (including computer generation)

The evolution of computers refers to the stages the computer has under gone through to its current version, there are many devices that have been used before the invention of the computers .These include the following; THE ABACUS This was the earliest device to be used for adding and subtracting. It was first used in Japan and China. THE SLIDE RULEThis device was invented in 1620’s by Willliam Oughtred .The device was used to carry out addition division, subtraction and multiplication. NAPIER’S BONESThe device was designed by John Napier .The device uses a set of ivory rods that looked like bones. The device was designed to solve mathematical calculations like multiplication, addition, subtraction and division. It is similar on principle to the modern slide rule.

THE MECHANICAL ERAThis was the period between 1623-1944,The machines in this period had the following characteristics ;

a. Moving partsb. Electronic relaysc. Mechanical gearsd. Use of punched cards and tapes.

EXAMPLES OF MACHINES AND THEIR USES





PASCAL’S ADDING MACHINE. This was designed by a French philosopher and mathematician called Blaise Pascal. It was the first mechanical adding machine that uses a system of gears and wheels.LEIBNIZ’S STEPPED RECKONERThe device was invented by a German man called GOTTFRIED Wilhem Von Leibruit .The device was used to perform arithmetic operations like addition, multiplication, subtraction and division.JACGUARD LOOMThe machine was invented by French man called Joseph Marie Jacguard.It was the first machine to store programmes using metal cards punched with holes to determine the settings for the loom. The loom could be programmed to weave the entire rug in a complicated pattern.DIFFERENCE ENGINEThe machine was invented by Professor Charles Gabbage an English man. He proposed a new calculator that was in many ways the fore –runner of today’s computers. He was the professor of mathematics at the University of Cambridge; He proposed the construction of a difference engine that could carry mathematical calculations. ANALYTICAL ENGINEThis was the engine which combined the concept of mechanized calculation and stored program. This was also invented by Charles Babbage .He also proposed the possibility of even more capable device the Steam –Powdered machine that could manipulate and store data.PROGRAMMED LOOPThe machine was invented by Ada Augusta Byron who collaborated with Charles Babbage on some of his scientific wittings and came up with a programmed loop. This was the device which could be programmed to conditionally loop or repeat in order to carry out the sequence of steps that are part of mathematical calculations.CENCUS TABULATION MACHINEThis was the machine which used punched cards to store data and tabulate data. The machine was first proposed by Charles Babbage and Ada Augusta Byron but finally designed by Dr Herman Holerrith in 1890.To tabulate means to draw table and fill in it data

COMPUTER GENERATIONS





Def; Computer generation refers to the advancement of computer technologies over a period of years.The term generation means the state of improvement in the development of a product.There are five computer generations;a. First computer generation.b. Second computer generation.c. Third computer generation.d. Fourth computer generation.e. Fifth computer generation.

THE FIRST COMPUTER GENERATION,This was the generation between 1944-1959 (USE OF VACCUM TUBES)It was characterized by the following key characteristics;1. Computers were very large, room sized computers.2. Used thousands of vacuum tubes for internal operation.3. Had so many wires.4. They had maintenance problems.5. They had limited primary memory.6. Used punched cards and paper tapes for in put and out put was

displayed out.7. They generated a lot of heat.8. Consumed a lot of power.9. They were not reliable because of their design which relied on the

Radio tubes.10. Programming was mainly done by machine and assembly

language and could solve one problem at a time.11. Introduction of the first electronic computers, the electronic

Numerical integrator and calculator.12. Introduction of the IBM 705 in 1955.NOTE; Vacuum tubes are small light bulb size electronic tubes with glowing filament.

The computers of the first generation included the following;

AUTOMATIC SEQUENCE CONTROLLED CALCULATOR This was invented by Howard Aiken of Howard University .It was used only for numerical calculation.





ATANSOFF –BERRY Computers (ABC).This computer utilized the logical operation to perform addition and subtraction. I was invented by professor John V Antansoff and Cliffold E-Berry. Electronic numerical integrator and calculator(ENIAC)This was developed by J Prosper Eckert and William J Mauchley.It was used to solve defense programs dilemma. UNIVERSAL AUTOMATIC COMPUTERS (UNIVAC I)This was the first computer to be used for census bureau and was the first produced computer for business. It was produced by Maurchley and Eckert. ELECTRONIC DISCRETE VARIABLE AUTOMATIC COMPUTER

(EDVAC) This was produced by Mauchley and Eckert .This computer utilized the idea of an electronically stored program. It was produced in 1947.THE SECOND GENERATION COMPUTERS 1959-1964(USE OF TRANSISTORS)The key characteristics of this generation were;1. Use of transistors for internal operations 2. Introduction of high level programming language e.g Basic and

COBOL.3. Computer became less expensive.4. Computers gave less heat.5. Processing speed increased.6. Computers were small.7. Computers became more reliable.8. Introduction of super computers e.g. Livermore Automatic research

computer (LARC).9. Introduction of first translator based computer the model 1401 in

1959.10. Computer used less power.11. Computers consumed less power as compared to the first

generation.

THE THIRD GENERATION COMPUTERS (1964-1971) (USE OF INTEGRATED CIRCUITS)The key characteristics of this generation were;





1. Introduction of integrated circuits or IC semi –conductor device conductors with several transistors built into one physical component.

2. Introduction of operating (OS) e.g. Multics)3. There was the use of parallel processing.4. Low cost computers were produced.5. High reliability computers.6. IBM Company produced the RPG programming language in 1960.7. Computers were more smaller8. Low power consuming computers were produced.9. Nicholas Wirth developed the Pascal programming language.

THE FOURTH GENERATION COMPUTERS (LARGE SCALE INTEGRATION CIRCUIT (LSIC)The key characteristics were;1. Use of large scale integration and very large scale integration circuits

(VLIC).2. Apple Computer Company began selling Apple 1 micro computers.3. Development of micro processing.4. Computers became more powerful and cheap.5. Lap top computers were produced in 1988.6. Multi - media using sound and video devices appeared in commercial

application.7. The Intel 14004 a special microprocessor was created in 1971.8. The IBM co-operation begins selling IBM PC in 1981.9. The computers were relatively small.10. Computers were more speedy and consumed very little power.

THE FIFTH GENERATION COMPUTERSThe key characteristics of this generation are;1 Use of artificial intelligence.2 Computers based on the use of artificial intelligence (AI) are expected to behave like humans and engage in discussion with human beings.3 More users, new multi media, fast connection and virtual reality services will be in place.4 Small sized computers are being used today.





5 Computers that use parallel processors are being developed along with new soft ware designs.

6 Computers are so fast.7 Computer s of today generates less heat and consumes less power.8 The computers of the fifth generation, internet is expected to be

universal like Radio and television.9 Reduced instruction set computer technology is being used to

develop a very faster computer.

1.3 uses and functions of a computer in our societyo Educationo Researcho Businesso Healtho Communicationo Military/securityo Homeo Entertainment / leisure

a. GOVERNMENT INSTITUTIONS Some of the government institutions include finance, planning, education e.tc. Computers are used for the following functions;

i. Keeping government records.ii. Improve efficiency within the civil services.

b. EDUCATION AND RESEARCH. - Computers are used as teaching aids. - Computers are for long distance learning. - For research, they are used for accessing reference materials.

C - COMMUNICATION INDUSTRYo In telecommunication industry computers are used to switch

incoming and outgoing calls.o Railway Corporation, computers are used to co-ordinate the

movement of their wagons and goods.





o In Air line industry. Computers are used for Air traffic control and surveillance of Air space using Radar equipment as well as for reservation purposes.

o Shipping and cruise liner industries, computers are used to speed up cargo handling and passenger booking.

D. POLICE AND DEFENCE. To keep database of finger prints Used in electronic intelligence gathering and military laser guided

missile system. For base face recognition to analylise the traffic offenders and

criminals.E-HOME AND LEISURE Provide people with list of shopping items and electronic money

transfer. For entertainment For playing gamesEMPLOYMENT Keeping the records of the employees

1.4 Computer care and safetyRules and regulationsMost institutions in Uganda have computer Labs with safety rules to follow when using them. There are a lot of machines and other equipment items kept in the Labs and it’s absolutely necessary to ensure that no one carries out an action to damage the equipments. Below are some of the rules

Install fire extinguishers to help in case of fire out break Do not bring any food or drinks near the computers Do not use external devices flash disks without scanning them for

computer viruses Ensure that the temperature in the room stays cool since there are

many machines in the lab which can over heat easily Dust can affect computers so ensure that all computers are always

clean

Management of computersComputer management is the process of managing, monitoring and optimizing a computer system for performance, availability, security or any other operational requirement.





It is broad term that includes manual and automated administrative processes in the operations of a computer.

Computer management includes various tasks such as:

Updating or patching a computer’s operating system with the latest updates and fixes

Installing, configuring and executing anti-virus/anti-malware software on a computer to identify, remove and provide protection against malicious attacks

Managing all components on the computer in relation to drivers, permissions and basic functioning

Creating and managing users Troubleshooting hardware, software or network and Internet errors Using disk defragmentation and disk cleanup services to remove

unnecessary data and improve disk response Enabling, disabling and optimizing startup and background

applications to increase/maintain processing speed.

Maintenance of computers

Computer maintenance is the practice of keeping computers in a good state of repair.

Computer cleaning involves physically cleaning the interior and exterior of a computer, including the removal of dust and debris from cooling fans, power supplies, and other hardware components. This should be done after certain period of time (weekly/monthly).

A computer needs to be maintained in order to keep working properly and in good shape and contributes to keeping computer troubles at bay.

Typical computer maintenance tasks include backing up your files, running antivirus software, installing software updates, using disk tools to keep your hard disk in good shape and physical cleaning of your equipment.

Back Up Your Files




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One of the most stressful experiences for a computer user is data loss. Most computers use a hard disk drive as the primary storage device. Hard disk drives can function for many years, but at some point, they will crash.

One of the solutions is to create a backup of your files. You can burn a CD or DVD with your most critical files, copy your files to an external hard disk drive or use an online backup service. Whatever strategy you use, just make sure you create a backup copy of your files on a regular basis.

Use Antivirus Software

Computer systems face a number of security threats. The most serious threats consist of viruses and other harmful programs.

A computer virus is a computer program that can cause damage to a computer's software, hardware or data. It is referred to as a 'virus' because it has the capability to replicate itself and hide inside other computer files.

The best way to deal with the threat of computer viruses is to use antivirus software. Antivirus software helps to protect a computer system from viruses and other harmful programs.

Antivirus software prevents viruses from getting into your computer system, scans your online activity to make sure you are not downloading infected files also helps to detect and remove viruses from your computer system if you get infected.

Use Disk Tools

Disk tools include a range of different tools to manage hard disk drives and other storage devices. These are important because a hard disk drive failure can have disastrous consequences, including losing all your data. Keeping disks running securely and efficiently is an important part of overall computer maintenance.

Some of the recommended disk tools you should use on a regular basis are disk cleaning and disk defragmentation.





Do not download and install unknown software from Internet. This is the biggest mistake most of the PC users are doing. Some of this software can damage the Windows registry, which cause lot of errors.

Install anti Spyware program to detect Spyware tools.

Install a Personal Firewall. Most of the antivirus programs are bundled with Personal Firewalls these days. Personal firewall is a barrier between your PC and the outside world. This can protect your PC from hackers and Spyware tools.

Uninstall unnecessary programs installed in your PC.

Be very careful when you download music from the Internet. Always stick to one trustworthy web site.

Delete temporary Internet files.

Set-up your PC to Download and install “Windows Updates" automatically. Windows updates include Operating System patches for bugs and PC security related issues. These patches can reduce many unknown computer problems.

Software update is also called a patch because it's 'patching' the software.

Ethics and integrity in computer use Computer ethics refers to a set of moral principles that regulate the

use of computers. Or the human values and moral conduct relating to right and wrong

behavior/decisions made when using computers. Computer integrity refers to steadfast loyalty to a strict moral or

principled set of laws regarding computer useSome of the Computer ethics and integrity that should be put in mind when using computers include:





1. Respect the privacy of others. Do not in any way examine or change files or passwords belonging to others. Do not violate the privacy of individuals or organizations.

2. Respect the integrity of the computing systems. Do not develop or use programs that invade, damage, or alter computing systems or software. Do not in any way harass other users.

3. Always identify the user accurately. Never use someone else's account. Do not use fraudulent means to avoid accounting for the use of computing services.

4.5. Respect copyrights and licenses. To copy a licensed computer program is

illegal; it is indeed theft.6. Respect the intellectual property of others. Individual programming

assignments are expected to be done by individual students; do not take another's work or ideas to call your own.

7. Exhibit responsible, sensible use of computer hardware, software, and data.

1.5 Keyboard and navigationKeyboard. It’s an input device that converts letters and other characters into electric signals readable by the processor. It has a type writer area, function keys, cursor movement keys and numerical keypad. It’s a device which enables a computer user to communicate to the computer system.Different keys of the keyboard

a. Type writer area: this comprises of alphabetical letters from A-Z and numerical numbers 0-9.

b. Function keys. These are programmable keys that do specific tasks in a given application package.

c. Cursor control/arrow keys. These control the movement of the cursor within the screen.

d. Space bar. This moves the cursor one step or position to the right and it is used to provide space between words or letters.

e. Back space key. This is used to erase any character to the left of the cursor. It also moves any word or sentence to the right of the cursor.

f. Delete key. This erases any character on the right of the cursor and moves any word or sentence to the left or towards the cursor.

g. Keyboard status keys. These control the state of the keyboard. They include; shift key, caps lock, Num lock, Alt key and Ctrl key.

h. The shift key. This enables one to access the character or symbol which appear on top of some keys. It also opposes the effect of the caps lock.

i. The caps lock. This facilitates the typing of alphabetical letters in upper case or lower case.





j. The Num lock. This enables one to use the numerical keypads.k. The Enter key. This is used to confirm a given command as instrument for

execution purpose. It also helps to start a new paragraph or sentence.l. The Alt key. This is used to make a menu ready for selection of items on it.m. The Page Up key. This is used to move the cursor up by one pagen. The Page Down key. This is used to move the cursor down by one page.

Pointing devicesA pointing device is an input device. It is used to control the movement of the pointer or cursor on the screen.

Uses of pointing devicesThey can be used for:

Sending command signals to the computer.

Selecting items on the screen.

Selecting commands from commands menu. Drawing graphs etc.

Most Important Pointing DevicesThe most important pointing devices are as follows:

1. Mouse2. Trackball3. Pointing Stick4. Joystick5. Touch Pad6. Touch Screen7. Light Pen8. Digitizer/Graphic Tablet

1- Mouse

Mouse is the most commonly used pointing input devise. It is used to control the cursor or pointer on the screen and to give commands to the computer. It is very easy to use. The mouse is attached with the computer by a cable or wireless connection.





The top of mouse contains one wheel and 2 or 3 buttons. These buttons can be clicked or double clicked to perform different tasks.

Example: For example, an object (icon) on the screen is selected by clicking the left button of mouse. Similarly, a program or folder is opened by double clicking the left button of mouse.

Types of Mouse

The most popular types of mouse are as follows:

(i) Mechanical Mouse:

This has a small ball at the bottom. The ball rotates as the mouse is rolled over a flat surface. Usually, a rectangular rubber pad (known as mouse pad) is used as flat surface. As the mouse is rolled over the flat surface, the pointer moves in the same direction on the screen.

(ii) Optical Mouse: It has no ball at the bottom. It uses the laser technology to detect the mouse movement. Nowadays, it is commonly used in personal computers (PCs).

2-Trackball A trackball is a pointing input device. It performs functions like a mouse but it is a stationary device. It has move-able ball on its top. The ball is rotated or rolled with fingers (or palm of the hand) to move the pointer on the screen. Like mouse, a trackball also has buttons used to send the commands to computer.

The trackball is usually available laptop compute. It is fixed on its keyboard. It is also available as separate input device.

3- Touch Pad




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Touch Pad is a pressure-sensitive pointing device. Touch pad is also known as track pad. It is also stationary device like trackball but it has no moving arts. It is a small, flat surface (or sensitive pad) over which a user slides fingertip to move the pointer on the screen.

Touch Pad also has one or two buttons. These buttons are located near the pad. These buttons work like mouse buttons. Touch Pad is normally used with laptops. Nowadays, it is also available as separate input device. It is fixed on separate keyboard.

4- Pointing Stick

A pointing stick is a pressure-sensitive pointing device. It looks like a pencil eraser. It exists between keys of keyboard. It is used to control the movement of a pointer on the screen. The pointer in the screen moves in the direction in which the pointing stick is pushed. Pointing stick input device is normally used with laptop computers.

5- Joystick

Joystick is a pointing device. It consists of a vertical handle or hand-held stick. The stick is mounted on a base. The hand-held stick is used to control the movement of pointer on the screen. Joystick also contains one or two buttons. The button of the joystick is pressed to activate certain event or action. Joystick is basically used to play video games. It is also used in some computer-aided design (CAD) system.

6- Touch Screen

A touch screen is a special video display screen. Input is given to the computer directly by touching the screen with user fingertip. Most touch screen computers use sensors in the computer's screen to detect the touch of a finger. Usually touch




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screen used to make selection from a menu of choices displayed on the screen. Touch screen is often used in ATM. Touch screen systems are also used in restaurants, supermarkets, departmental stores etc.

In some computer systems, pen-based or light pen input devices are used. The user touches the screen with a pen. However, the term touch screen implies a system that accepts input data by touching the screen with the user's fingertip.

7- Light Pen

The light pen is a hand-held pointing input device. It looks like a pen. It is a light-sensitive input device. It is connected with the computer by a wire. The tip of pen contains a light-sensitive element. This device also contains a button.

Input is given to the computer directly by touching the screen with pen. When the pen is touched with the screen, it detects or senses a position on display screen. The user points the object to be selected on the display screen and then presses a button on the light pen.

Light Pen device is usually used by engineers and graphic designers. This input device requires special monitor. Light pen is used in Personal Digital Assistant (PDA) and other types of hand-held computers.

8- Digitizer or Graphics Tablet

Digitizer is used for drawing new images or tracing old images. Usually, it is used for making maps and engineering drawings. A digitizer is also known as graphics tablet. It consists of a flat, rectangular board (or pad) and an input device stylus or puck. Each location on the rectangular board points to corresponding position on the computer screen. The stylus or puck is connected to the board / pad by a wire.

SENIOR ONE TERM: TWO




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1.7. CATEGORIES / CLASSIFICATION OF COMPUTERSComputers are broadly classified into the following:Classification by capacity/sizeClassification by powerClassification by purposeClassification by function

CLASSIFICATION BY CAPACITYThis is the classification of computers in which we look at the physical size of a computer (its volume) and the number of people the computer can accommodate at a time. Computers under this category include the following;

a. Main frame computersb. Mini computersc. Micro computersd. Super computers/Monster.

Main Frame Computers i. They were very large almost to fill the whole room.

ii. They were water or air cooled computers.iii. They were very expensive.iv. It could accommodate up to 1000 people at ago.v. They were the earliest computers which were around up to

1960’s.vi. Main frame computers have several powerful processors.

vii. Mainframe computers can process large amounts of data quickly.

The examples of the main frame computers are; IBM 4381, ICL39 series and CDC Cyber series.Mini computers

i. They were the small versions of the main frame.ii. They were less powerful in operation than the main frame

computers.iii. They have fewer processors and they can support up to 100 users at

ago.iv. They can be- used in banking institutions, education establishments

and developed areas.v. They are also protected from external environment.





vi. They have the same basic structures as the larger main frame computers and support the same peripheral devices supported by the main frame.

vii. The min computers are heavily used as net work servers in the business industry.

SUPER MICRO COMPUTERS/MONSTERThis is the heavy powerful computer which can support up to 4 users at a time.

i. They are computers with a high mathematical capabilityii. Large computers with fast processing using multiple processors and

superior technology hence can process trillion of instructions per second.

iii. Super computers are mainly used for research purposes, aeroplane design ,oil exploration ,weather fore casting, for space calculation and other activities that cannot be handled by the main frames and less powerful machines.

iv. They are the biggest computers and most expensive than any other computer we have.

v. It is used in entertainment industry for animation.Examples are CRY T3D and NEC 500.

THE MICRO COMPUTERSThese computers have the following characteristics;

i. These are smaller computers that serve a single user at ago .ii. They are mainly used in homes ,offices, and are commonly referred

to as personal computers.(PC’s)iii. The heart of the microcomputer is the microprocessor (a single chip

containing the arithmetic and logic units.)Examples of micro computers are Tower PC’s Desktop computers lap tops, Note books, and personal Digital, assistant or palm tops.

Note book computers; This is the smaller version of the laptop computers .It is of a small size and low weight and easy to carry any where .It can store the same amount of data and having a memory of the same size as that of the personal computer.

Personal computer (PC’s) These are also small sized computers, small in size and of less cost .Examples are the Desk tops and laptops.





Laptop computers; These are light weight computers with built in monitor, keyboard, hard disk drive, battery and adapter that can be plugged in the electrical outlet.

Tower pc’s are those in which the case sits as a ’tower’ often on the floor besides a desk.

Personal digital assistants (PDA’s) These are also known as hand held computers or palm tops ,combine personal organization tools (schedule planners ,address book to-do lists)with the ability in some case to send faxes.

Desk top computers; Are those in which the system unit or the main housing sits on a desk, with key board in front and monitor often on top.

CLASSIFICATION BY FUNCTIONFunction refers to how the computer was designed to operate.The three categories of computers under this class are;

i. Digital computers ii. Analog computers

iii. Hybrid computers.

Digital computersThese are computers which carry out their operations in distinctive steps using digits. These computers deal with data represented as a series of 0’s and 1’s. They perform their operation by noting the presence or absence of physical signals in a particular position.They are used primarily for administrative data processing and mathematical computation and are the most common used computers.Analog computers;Are the computers which operate by the use of measurement and they use continuous values as opposed to discrete values.They are sensitive to the environment and they measure the physical quantities such as temperature, humidity, speed, voltage, weight, pressure, length, flow e.tc.They are special purpose computers designed to solve scientific or technical applications and are quite rare in commercial fields.They perform their tasks by measuring continuous physical variables,( like length, pressure, weight, voltage, humidity e.t.c)





Examples of analog computers may include; thermometers, car speedometer, barometer e.t.c. They are used scientific and engineering purposes.

Hybrid computersThese are the computers which combine the features of the analog and digital computers. A highbrid computer is the combination of an analog and digital computer linked together by an interface system for converting analog data to digital and vice versa. They are used in scientific research and other specialized applications.

CLASSIFICATION BY PURPOSEIn this classification, computers are classified according to what they were designed to do. Some are designed to perform general duties while others do specific duties. These include;

i. Special purpose computers.ii. General purpose computers.

Special purpose computerThese are the computers which are designed to perform specific tasks or a particular specific purpose.They are found in scientific laboratories where they perform complicated mathematical operations.Examples of such computers are;a. Missiles b. Pocket calculatorsc. Building lifts.

They perform a specific number of functions.

General purpose computersThese are the computers which are designed to a wide variety of operations using a wide variety of programming languages .Such computers are found in Universities where different types of programmes are written.Examples of such programmers are;

a. Registration by staff.b. Research by professors.c. Class assignments.

Classification by power





This is the classification of computers according to the processor power.Examples of such computers are;386 processor running at less than 33 MGz speed ,486 processor with speed ranging between 33-66 MHz ,Pentium I,II,III and IV the speed ranges between 77 MGz 2.5 GHz and above.

1.8. The computer systemA computer system is the set of interrelated elements working together in an integrated way to achieve a set objective. Or A computer is the a multi purpose electronic machine that is capable of accepting data ,storing the data ,processing the data and finally outputting the processed data (information) through its out put devices in a form that it is usable by humans. The four main components of a computer system are;Data; This is the raw material that is fed into the computer to be processed.Computer hard ware; This refers to the physical or tangible parts of a computer.Computer soft ware; These are instructions or programs a computer must follow to accomplish a given task.Human ware or live ware; This is the user or a person who operates the computer.Data and information have been defined above.Information communication technology (ICT)ICT means the scientific mean of sending and receiving information using the scientific means e.g. computers, networks, internet, e.t.c which requires understanding and feed back.ICT brings together technologies used in the collection, storage, processing of data, and in the transmission and retrieve of information, together with associated methods and applications. TYPES OF INFORMATION SYSTEMSThe two forms are;

a. Manual information system.b. Computerized information system.

Data processing is the same whether manually or by the use of a computer.





Computers use programs instead of instruction books and they store data on disks and tapes instead of filling cabinets but their work still follows ,the input ,processing, output and storage pattern.When compared with human beings;a. Computers can process data more quickly.b. Are generally accurate (where as human beings are prone to errors).c. Can process both larger volumes of data and more complex data.d. Store larger volumes of data.e. Share information at a very high speed with other computers using

networks.However manual or human data processing is more suitable when judgment is involved in the work (remember computers don’t think though it is said we are entering or we have rather entered the fifth generation of computers where computers will behave as if they think by using the Artificial intelligence (AI technology).

ADVANTAGES OF USING COMPUTERSSpeed; A computer is speedy as it can take Millions of instructions per second. Storage; a computer can store data and information for along period of time and safely.Versatile; Computers are versatile as they can do different things at the same time.Flexible; Computers are flexible as they can do other works of other machines like phones, radio, fax e.t.c.Recreation; Computers offer recreational facilities like games, sports, movies e.t.c.Accurate; Computers are very accurate but their accuracy depends on the users degree of accuracy .That is why we have the saying GIGO (Garbage in Garbage out)Diligence; Modern computers can work for so long hours without getting bored or tired.Volume and complexity; Computers are capable of handling big volumes of data and complex materials.Access to information; The use of data base and the ability to link a number of users via some form of network improves the distribution of information within and beyond the organization.





Interactive; A computer is interactive, it can respond to instructions given to it.Communicative; A computer can communicate with one another through net work and Internet.a. Computers are convenient to use.b. Computers produce neat work.c. Computer is programmable.d. Computers are economical.e. Computers can automate work.

DISADVANTAGES OF USING COMPUTERSUn employment; Computer lead to un employment by taking most of the work that humans would have doneCost; Initial cost of computers is high and maintenance is rather expensive.Fatigue; Computers cause fatigue as the result of spending a lot time using them.Delicate; Computers are delicate thus have to be handled with care.Viruses; Computers are affected by computer viruses that undermine their operation and credibility.Piracy; Piracy means accessing the computer system illegally for the purpose of stealing the documents (information) or soft ware .This is another computer crime.Hackers; This means the process of accessing the computer illegally but with no intention of stealing the documents e.g playing games. Eye defect; Due to direct light the eyes may be spoilt. Use screen protective.Pornography; This refers to showing naked people or sexual acts in order to cause sexual excitement.

SENIOR ONE TERM: THREE

TOPIC 2: COMPUTER HARDWARE





Computer Hardware is defined as the physical or tangible part/components of a computer. These are different parts of a computer that can be seen and touched like monitor, printer, keyboard etc.

2.1 Types/Categories of computer hardware Input devices Output devices Storage devices Processing unit

Input devicesThese are hardware devices that are used to feed data and instructions into the computer. They include; a keyboard, scanner, mouse, digital cameras, joy stick, smart cards, credit card, automated Teller Machine card (ATM card), light pen, magnetic ink character reader(MICR), optical mark reader (OCR), bar code readers, optical character readers, touch screen, digitizer among others.

Keyboard. It’s an input device that converts letters and other characters into electric signals readable by the processor. It has a type writer area, function keys, cursor movement keys and numerical keypad. It’s a device which enables a computer user to communicate to the computer system.

Mouse. This is a hand held pointing input device used to control the movement of the cursor on the computer’s screen. A mouse can be used to point, select, move and draw object in the computer screen. Examples of mice include: codeless, touch pad (touch tone pad), mouse stick.

Scanner. This is a device that is used to input graphical hardcopy data or information into a computer in a softcopy form e.g. logos, emblems, photos, pictures etc. scanners are usually used to capture existing documents in an electronic form for further processing or incorporating into other documents.

Text and graphics can be scanned and images can be manipulated by changing the colors, the sharpness and contrast etc.

Types of scannerso Hand scanners. These are used in scanning small objects e.g. logos,

signatures, emblems, budges, thumb prints etc.o Flat bed scanner. These are heavy scanners which are used for scanning

commercial photos and pictures.

Credit card. It’s a small plastic card that allows its holder to buy goods and services on credit and to pay at fixed intervals. It has a strip of magnetic tape fixed on it containing coded information which is usually the owner’s code. The card is





inserted into a slot where magnetic data may be picked. Details of the transaction are then recorded against the credit card number and the owner’s account is credited with the transaction.

Barcode reader. Most items manufactured are labeled with a Universal Product Code (UPC), identifying the items .the label code is in terms of bars with coded spacing and thickness. These bars contain information in code that a computer can interpret. Most supermarkets today use this system and the codes can be seen on every item on stock. This enables fast pricing, identification and accurate stock tracking/taking. A bar code reader is a device used to read these codes and send request to central computer on which the database of the organization is stored, the central computer sends a response about the product details i.e. its price, name, manufactured date etc.

Optical mark reader (OMR). This is a device which can detect the presence or absence of a mark on a paper. Light is shown onto the paper and the reflected light is detected. This device is used for reading answers to questions in an exam or survey.

The magnetic ink character reader (MICR). This is used to read characters written using magnetic ink. They are used in banks to read cheques and at points of sales in shops.

The voice recognition device (VRD). This is used to recognize words from a person and follow the instructions. An example of its use is in a computer which opens money safe, if the correct password is said.

The joystick. It’s a device connected to a terminal with a control level that can be moved or titled in various directions for moving the cursor to any position on the screen. It’s commonly used in computer graphics and in playing games.

A light pen. It consists of a stylus connected by a cable to the terminal that can sense the light from a position on the screen and convert it into an electrical signal transmitted to the computer. It can be used to move or delete images on the screen or to create new images.Touch screen. With touch screen, users of computers just have to point on a particular item they want to select from the screen using their fingers. When a particular part is touched, the screen can sense that part and the item in that area will be selected.

Digital cameras. These take photographs like normal cameras do. The only difference is that digital cameras do not create an image on a film like ordinary cameras but instead the image is stored on the camera and after downloaded onto a computer for editing and printing.





Output devicesThese are components which display out the information that is being processed by the computer to the user. They include:

Monitor / Visual Display Unit (VDU) Printers The loud speakers Plotters projectors

The monitor. This is a device which shows/gives the soft copy of the data/information in the computer.

TYPES OF MONITORSMonitors are categorized into two types which include

Cathode-ray tube (CRT) monitor LCD (liquid crystal Display) monitor

Advantages of CRT monitors over LCD CRT monitors have wider view angle than the LCDs CRT monitors are resistant to harsh conditions like dusty conditions CRT monitors are cheaper than LCDs CRTs have a very fast response time CRTs are not affected by the problem of dead pixels as images are

painted on the screen Etc

Disadvantages of CRT over LCDs- CRTs consume a lot of power than LCDs- They consume a lot of space i.e. they are big in size- They are not portable

Advantages of LCDs over CRTs- They use less power than CRTs- They are portable - They emit less radiations than CRTs

Disadvantages of LCDs over CRTs- LCDs have a small view angle than the CRTs- LCD monitors are not resistant to harsh conditions like dusty

conditions- LCD monitors are expensive than CRTs- LCDs are affected by the problem of dead pixels as images are painted

on the screen etc.

Printers.





These are devices which gives a hard copy of the processed data or information held in the computer.

Printers are output devices that produce text and graphics on paper. They are connected by a cable to a PC through either the serial port or the USB port

Types of printers:They are basically two types of printers i.e. impact and non-impact printers.

Impact printers are the ones which print by physically striking their print heads on the printing media like paper, cloth etc. e.g. Dot matrix printer which print using a set of pins on a print head, Daisy wheel printer which print using a wheel of characters etc. Their print heads press the paper with the ribbon to produce the printout.

Non-impact printers are the ones which print by not physically striking their print heads on the printing media like paper, cloth etc They use chemicals, laser or heat to produce the image. They give out high quality printouts. E.g. laser jet printers which uses toner contained in toner cartridges and ink jet printers which use ink contained in ink cartridges.

Advantages of daisy wheel Can print letter quality characters

Disadvantages Their speed is very slow

They can’t print graphics

Advantages of dot matrix printers They can withstand dusty environment, vibrations and extreme

temperature. They can print on continuous paper or multipart documents. They are the only printers which can use stencils. They are relatively cheaper.

Disadvantages They are generally noisy because of the striking mechanism. Print quality of Dot-matrix is not as good as those from ink-jet printers and laser

printers. They are relatively slow. They are not readily available on the market. They are not easily serviced because they are based on old technology. The color print is limited to two i.e. black and red.





Advantages of impact printers The cost of impact printers is low. More tolerant to a variety of print media (paper types) Less sensitive to environmental conditions can print in hostile environments.

Disadvantages Poor quality print Lack of flexibility and performance with respect to complex fonts, images and color Non-impact printers are quiet. These are printers that use chemical lasers to form

images that eventually become characters. They form characters and graphics on a piece of a paper without actually striking the paper e.g. LaserJet printers.

They use chemicals, laser or heat to produce the image. They give out high quality printouts. E.g. laser jet which uses toner contained in toner cartridges and ink jet which uses ink contained in ink cartridges.

Advantages of laser jet printers They produce a very high quality output. Are very quiet and very fast They are capable of producing color prints Their maintenance cost is also low as toner takes long to get finished

Disadvantages They are expensive to acquire The toner they use is hazardous to human life.

Advantages of Ink-jet printers Color ink-jet printers are cheaper to buy than color laserjet printers They are generally quiet and not noisy like the Dot-matrix. Can produce high quality color output They are also cheap as compared to the laser printers

Disadvantages They have a low printing speed compared to the laserjet printers. They also require specialized paper to produce high quality color output. They are expensive to maintain.

Storage devices

These are devices used to store processed data either permanently or temporarily. E.g. RAM, hard disk, flash e.t.c

Storage devices are divided into two categories;- Primary storage devices- Secondary storage devices





Secondary storage devices or auxiliary storage devices are devices used to store information/data permanently even when power is switched off (its non-volatile)Examples of Secondary storage devices

Hard disks Floppy diskettes Compact disks Digital versatile disks Flash disks Memory cards Etc

Types of secondary storage devices1. Magnetic secondary storage devices2. Solid state secondary storage devices3. Optical secondary storage devices

MAGNETIC SECONDARY STORAGE DEVICESi. Magnetic tape: is a storage medium that consists of a thin tape with a

coating of a fine magnetic material used for recording digital data. A device that stores computer data on a magnetic tape is a tape drive.

Magnetic tapes generally transfer data a bit slower than hard drives, however magnetic tapes are cheaper and are more durable.

ii. Floppy diskette: is secondary storage medium that can be used to store data in a permanent manner. It stores data in form of tracks and sectors.The device used to read data on the floppy disk is called a floppy disk drive. The capacity of the floppy disk is 1.44MB.

iii. Zip disks: is a high capacity floppy disk drive that is slightly larger than a normal floppy disk. They can hold 100 or 250 MBs of data, they are durable and good for backing up data

iv. Magnetic hard disk (Commonly known as Hard disk): is the main and usually largest data storage device in a computer. It’s a non-volatile random access digital magnetic data storage device, a hard drive is made up of platters which stores data and read/write heads to transfer data.





A hard disk is generally the fastest in all secondary storage devices and has the largest data storage capacity.Hard disks are not very portable and are primarily used internally in a computer systemData on the hard disk is positioned in tracks and sectors so that can be easily read by the heads

Advantages of magnetic storage devices- Inexpensive storage- There is direct access on any part of a drive- There is very fast access to data - Very large amounts of storage space

Disadvantages of magnetic storage devices- Data can be altered by magnetic fields, dust and mechanical problems- Gradually lose their charge over time ie there is data lost over time- Hard disks eventually fail which stops the computer from working.- Cannot transfer the disk to another computer easily

SOLID STATE SECONDARY STORAGE DEVICEThis is a data storage device based on electronic circuits with no moving parts. Solid state devices use a special type of memory called flash memory.Flash memory is a type of electronically Erasable Programmable Read Only memory . flash memory is non-volatile but data stored in it can be erased or changed. Examples of solid state storage devices

i. Memory cardsii. Flash disksiii. Smart cards

Floppy disk. This is small portable plastic disk used to store data or information. It utilizes its magnetic properties to keep data or information.

Digital Versatile Disks (DVD’s). They look exactly like CD’s except that DVD’s have got very big storage capacity than CD’s. CD’s have the capacity ranging from 500MB’s to 700MB’s but DVD’s range from 1 GB to 20 GB’s.

Zip drives. These are related to diskettes but they are bigger than diskettes in terms of size and storage capacity. They have storage capacity ranging from 100 MB to 2 GB’s.





Compact Disks (D’s) /Optical disks. They are categorized into o Compact Disk Read Only Memory (CD-ROM). With these disks, you just

read what is there but you cannot erase or write on them.o Compact Disk Recordable (CD-R). This type can be written to but only

once. This means that once you write on this disk, you can’t erase to write new information or make changes to the existing one.

o CD Re-writable (CD-W). These disks can be written to as many times as you want. This means that after writing on this type of disk, you can erase that data and write on it again.

Punched card. It’s a rectangular card used to store data by the presence or absence of small holes that can be punched in specific locations on the card. These cards were used with first computers before disks were invented.Magnetic tape. It looks like videotapes. They are made of plastic and are coated with the same type of magnetic iron oxide that is used on disks.

Precautions measures taken in keeping diskettes Do not fold, spindle or mutilate a disk. Do not place a diskette near a magnetic field such as near a radio speaker, on

top of your system unit or near electric motor etc. Do not expose a diskette to direct sunlight for long periods. Keep a diskette away from intensive heat. Always keep it in its jacket so that the exposed surface is covered. Do not drop it on a hard surface e.g. on the floor. Do not drop water on the exposed surface of the diskette. Do not expose it on X-ray. Do not insert or remove it from its drive when the drive active light is on. Do not force it into its drive. It should slip in with little or no resistance. Do not write labels directly on it. Use a felt pen.

Differences between hard disk and floppy disk Hard disk floppy disk

Stores more information stores less information Metallic plastic Fixed flexible Reads information faster it is slow Exposed to less risks exposed to more risks

The primary memory It is the space for keeping data or information in the computer. The primary memory consists of two components namely;

ROM (Read Only Memory) RAM Random Access Memory (the main memory of the computer)





ROM. This part holds information which was put there at the time of manufacturing. It can’t be modified and additions can’t be made. A computer has a set of in-built instructions It has to know what to do when turned on.The instructions built into ROM are permanent.The computer can read or follow instructions in ROM but can’t change them or add to them. That is why the memory is called Read Only.It’s a stable memory i.e. it’s not affected by power cut off. An example of ROM memory is the PC’s ROM BIOS (Basic Input and Output System) chip. This ROM chip contains a set of instructions that the microprocessor uses when the PC is turned on or reset.

There are five basic ROM types:

1. ROM - Read Only Memory2. PROM - Programmable Read Only Memory3. EPROM - Erasable Programmable Read Only Memory4. EEPROM - Electrically Erasable Programmable Read Only Memory5. Flash EEPROM memory

RAM (Random Access Memory/ Read Write memory)This is the memory of the computer that holds data that is input from the keyboard, data/programs read from the secondary storage devices e.g. diskettes and results after processing from CPU.RAM is also known as a user memory It allows the user to freely read from and write to it hence the name Random Access Memory.Note:- Information in this memory can be changed, deleted, copied and read.-This is the working memory and main memory of the computer.However, RAM is a volatile memory i.e. in case the machine is turned off or power goes off without saving all the information in the memory is lost.

Types of RAM:

There are three main forms of modern RAM: Static RAM (SRAM) Dynamic RAM (DRAM)and Phase-change memory (PRAM)

In SRAM, a bit of data is stored using the state of a flip-flop. This form of RAM is more expensive to produce, but is generally faster and requires less power than DRAM and, in modern computers, is often used as cache memory for the CPU. DRAM stores a bit of data using a transistor and capacitor pair, which together comprise a memory cell.




http://en.wikipedia.org/wiki/Central_processing_unit

http://en.wikipedia.org/wiki/Flip-flop_(electronics)

http://en.wikipedia.org/wiki/Bit

http://en.wikipedia.org/wiki/Phase-change_memory

http://en.wikipedia.org/wiki/Dynamic_random-access_memory

http://en.wikipedia.org/wiki/Static_random_access_memory


The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits.A bit is the basic unit of information in computing and digital communications. A bit can have only one of two values, and may therefore be physically implemented with a two-state device. The most common representation of these values is 0and1. The term bit is a contraction of binary digit.

Types of memory:

DRAM (Dynamic memory). This form of memory is used for system RAM. It is made up from thousands of electronic components called capacitors that store ones and zeros as electric charges. These are refreshed hundreds of times a second, which is why the term Dynamic RAM is used.SRAM (Static RAM) it’s much faster than DRAM and larger in size. It retains its data as long as power is supplied to it and it does not need to be refreshed constantly.

Processing device/ processor

This is the heart of the computer where the entire processing takes place. It is sometimes referred to as the brain of the computer. It is the center of activities in the computer hence referred to as Central Processing Unit.

The microprocessor does the following:o Carries out commands to make the hardware components perform actionso Processing data. This involves performing logical instructions such as

comparing and performing mathematical instructions such as adding and subtracting.

A CPU comprises of the following parts;a. The arithmetic and logic unit (ALU): performs calculations and decisionsb. The control unit: coordinates processing stepsc. The registers (temporary storage): small storage area

The Arithmetic and Logic Unit (ALU):This is the component in the CPU, which handles all the arithmetic and logic operations of the computer system. It is actually the calculator of the computer system.The control unitThis is a component of the CPU which governs all activities within the computer. It interprets instructions stored in the main memory and gives instructions to relevant parts of the computer system.The registers




http://en.wikipedia.org/wiki/Value_(computer_science)

http://en.wikipedia.org/wiki/Communication

http://en.wikipedia.org/wiki/Computing

http://en.wikipedia.org/wiki/Information

http://en.wikipedia.org/wiki/Units_of_information

http://en.wikipedia.org/wiki/Bit

http://en.wikipedia.org/wiki/Telecommunications

http://en.wikipedia.org/wiki/Computing

http://en.wikipedia.org/wiki/Units_of_information


This is the component which stores instructions temporarily in the CPU while awaiting handling by the (ALU).

Communication devicesAn electronic hardware device that can send and receive data on the network. Most communication devices have the ability to convert the digital signal of a computer into analog signal so that the signals can be transmitted on communication line to another end. The reverse is true. They include:

ModemIt stands for modulator demodulator. The modem (dial-up modem) is an electronic device that can convert the digital signals into analog signals and analog signals into digital signals. It is used on both ends of the computers for data communication between computers through telephone line. We new that data is communicated through telephone line in the form of analog signals. So data in the form of digital signal from one computer must be converted into analog signals before to transmit it to another computer through telephone line. Similarly, receive of data from another computer through telephone line in the form of analog signals must be converted to digital before to store into the computer.

Digital modemThe modem that is used to send and receive data to and from a digital telephone line is called digital modem. The examples of digital modems are ISDN and DSL. These modems send and receive the digital signals to and from the digital line. This modem does not convert the digital signals into analog because digital lines already use the digital signals.

Network interface cardIt is also referred to as LAN adaptor or simply LAN card. It is used in local area network to establish the communication between the devices (computers, printers etc.) attached on the network. Usually the personal computers use the network interface card (NIC) in local area network. The Ethernet card is the most common type of network interface card.BridgeIt’s an electronic device that connects two similar networks and controls the data flow between them. A bridge looks at the information in each packet header and forwards data (that is traveling) from one LRN to another.

RouterAn electronic hardware device that connects multiple computers together and transmits data to its correct destination using the available path on the network. It stores the routing information of each node or computer on the network and to use these information to transfer data between nodes. Like a bridge, a router looks at each packet’s header to determine where the packet should go and then determines





a router for the packet to take and thus reach its destination. Some routers also support wireless communication.

GatewayIt’s an electronic hardware device that can perform logical functions. A gateway is a device or system (collection of hardware and software) that connects two networks and translates information from one to the other so that data can be transmitted between two dissimilar networks.

RepeaterA hardware device which is used to join same type of networks to extend the length of the communication medium. It also simplifies the signals received from one network and sends the amplified signals to another network.





SENIOR TWO TERM: ONE

TOPIC 3: COMPUTER SOFTWARE

3.1 Introduction to softwareSoftware is a general term used to describe the various programs, languages or routines that control the operations of a computer in solving a given problem. These are programs used in directing a computer in solving problems and overseeing operation.

It’s the software that instructs the hardware on what to do and how to do it.

Software can also be described as a sequence of logical instructions stored in memory that a computer executes in the processing of data.

Program. This is a series of step-by-step instructs that provide solutions and tell the computer what to do. They are logical arranged set of programming statement.

Software is broadly divided into (types of software):o System software and o Application software

Characteristics of softwareo Software does not ware outo Its intangibleo Scalabilityo cheapo user-friendly

doesn't wear outlabour intensive hackable

3.2 System softwareThese are programs which control and support all other computer programs and the hardware. They manage the computer system resources and ensure efficient running of the computer.

Types of System software: The operating system Software development tools (programming languages, compilers,

interpreters) The utilities (utility software) Data communication software





Operating systemThese are programs that manage the computer resources. Op supervises and manages the different activities that take place in the computer like the way the software uses the hardware. The operating system ensures that the computer operates in a systematic reliable manner.Types of operating systemSingle programming operating system e.g. MS-DOS (Microsoft Disk Operating System), CP/M (Control program for micro computers), XENIX, PC-DOS (Personal computer operating system). This operating system can run one program at ago. Multiple programming operating system e.g. UNIX, Zenix, Novel Netware, Ms-windows. This can run a number of programs at the same time.Functions of operating systemHardware management. It enables a computer to communicate with peripheral devices such as a printer, mouse etc. it controls all the input/output devices and the flow of data or information e.g. telling the monitor to display the results.Software management. It provides a mechanism for initiating processes that include programs such as Microsoft word and Microsoft Power Point.Data management. It manages files stored on a hard disk and other mass storage devices. It also performs file management tasks like renaming and deleting.It provides memory space to program for execution.Coordinate the flow of data between the various application programs and users.Provides services for obtaining data.It helps in multi-programming.It enables booting a computer.Sometimes they have in-built system utilities like debuggers and defragmenters which help in the maintenance of disks.It helps in mediating between the computer user and the computer system in order to help the user to interact with the computer hardware to obtain results.It coordinates all activities in the various parts of the computer.It alerts the user and reports errors.It manages resources such as the CPU and memory. It manages multi-tasking (doing many tasks at once e.g. printing, inputting and processing) and multi-programming (a technique of having more than one program in the main/ primary storage which programs may be running/ are being processed at the same time). For example, having a word document and excel spreadsheet open at the same time.Ensures automatic update of time and date on the computerIt determines the interface of the desktop. Some operating systems are command based and thus require one to type in commands (e.g. DOS) while others use graphics / pictures (e.g. windows XP)Controlling system security by maintaining the use of passwords. A password is a set of system before further access is permitted.

Multitasking, Multithreading, Time-sharing





Multitasking A processing activity that allows a user to run more than one

application at the same time Multithreading

A processing activity that is basically multitasking within a single application

Time-sharing A processing activity that allows more than one person to use a

computer system at the same time

Programming Languages: Terminology (1)

Language translator Systems software that converts a programmer’s source code into its

equivalent in machine language Interpreter

A language translator that translates one program statement at a time into machine code

Compiler A language translator that converts a complete program into machine

language to produce a program that the computer can process in its entirety

Software Development ToolsThese are system programs that assist in the preparation of a program and translate into machine code for execution. Examples include; language translators, compilers, assemble, editors, debug aids.

Utility softwareThese are system programs used to support, enhance or expand programs in a computer system. They can also be defined as software tools that are used to carry out organization and maintenance activities e.g. deleting of unwanted materials, deleting those programs which cause the computer to work abnormally etc.They are generally programs which perform tasks related to maintenance in your computer’s health, hardware and data. They include:

File management programs

Disk management programs

Memory management programs

Data recovery programs





Backup programs

Data compressor

Anti-virus programs

Backup up programs. These ones let you protect your files by making copies of them.

Data recovery programs. These are used to restore data that has been physically damaged or corrupted.

Data compression programs. These are utilities which are used remove redundant elements, gaps and unnecessary data from a computer’s storage space. Due to very large sizes of files used in multimedia (graphics, sound and video files) data compression is used to reduce the storage space required. There are two major types of data compression, lossy and lossless.

Lossy compression involves a certain loss of accuracy in exchange for great compression.

Lossless compression achieves compression by removing redundant data elements and does not achieve as much compression (1:4). An example is WINZIP.

Debuggers. These are programs which correct errors in a computer program.

A bug is an error in a computer program and to debug means to correct errors in a program.

Defragmenters These are programs, which bring fragments of a file together for storage in

one location in the computer memory. Disk maintenance Disk maintenance utilities like Norton disk doctor, scandisk etc. These

programs detect errors on a computer disk and fix them like checking for bad clusters on a hard disk or diskette and marking faulty ones as bad cluster.

Virus protection programs (Anti-virus programs)This is anti-virus software which protects your system from viruses. A virus is a piece of computer code or program that is hidden within an existing program. It overwrites or attaches itself to programs or data and destroys or corrupts data. A virus interferes with the normal running of a useful computer program.Anti-virus programs can be used to detect and remove viruses from your system and any other storage media. Examples of anti-viruses include; central point anti-virus, Mac fee, Norton anti-virus, Avast etc.Computer virusesThese are computer programs which silently replicate (reproduce) themselves on storage media without the computer user realizing it.These programs in many ways act much like a human virus that is why they are referred to as computer viruses.





When a computer virus begins to replicate (reproduce), it may or may not be designed to cause trouble. However, some computer viruses are very dangerous because they are designed to damage data.Types of computer virusesSometimes virus hide in different places on the computer and in the process, perform various damages to the computer. They include; File virus, Boot sector viruses and partition sector viruses.File virus. This type of virus hides in program files, especially those files which have extension. EXE and COM.Boot sector viruses. These viruses hide in the boot sector of a disk. This particular sector contains important information about the disk’s logical setup.Partition sector viruses. These hide in the primary sector of a hard disk. This area is where programs which start a computer are stored. When a virus gets to this area, it at times changes the programs it finds there. In the end, this may cause a computer not to start.Other viruses include: overwriting viruses, multiple viruses macro viruses, companion viruses etc.Sources of computer viruses

Freeware and share. When infected software is installed on computer, it will automatically get infected.

Contaminated diskettes

Computer games especially. Games downloaded from the internet

Updates of software distributed via networks

Symptoms of computer virusesExecutable files changing size for no obvious reason.Program taking longer than usual loadUnusual error messages occurring more frequentlyPrograms and files disappearing mysteriouslyAccess lights turning on for non referred devicesComputer indicating that storage devices are full when there is still enough spaceWays of keeping computer virus programs out of your computer

Getting aware of how computer viruses get into your computer for example some viruses are written to ride along with another computer program. When a computer user inserts a disk into a computer with an infected program on it, the virus is duplicated in the computer.

If you are aware of how computer viruses are transmitted, you can avoid them by being careful about which program to use.

Using special virus detection program. These programs analyze every program and every disk that is inserted into the computer to make sure that it is not caring any virus. If it does have a virus, detection program can be used to





eliminate a found virus from a disk. Example of such programs include Norton anti-virus tool kit, Dr. Solomon’s anti-virus tool kit etc.

Avoid external disks especially diskettes as they may be carrying a virus. If you have an anti-virus program, first check your disks before using them.

You have to be careful when downloading programs (freeware, shareware, computer games etc.) from the internet as some of the programs contain viruses.

Perform a virus scan on your computer at least once a week and also other storage media like your diskettes, backup tapes etc.

Always remember to update your anti-virus software. Every day, new viruses are created and the designers of these virus programs first look at the available anti-virus programs so that they can create a strange virus which can bypass those programs.

Characteristics of system software

Functions of system software

The three major functions of system software are allocating system resources, monitoring system activities, and disk and file management.

1. Allocating system resources: The system resources are time, memory, input, and output. The time in the CPU is divided into time slices. The time slices is measured in terms of milliseconds. Based on the priority of tasks the time slices are assigned. Memory is also managed by operating system. Disk space is the part of main memory. The data flow is controlled by operating system.2. Monitoring system activities: The system security and system performance is monitored by system software. System performance includes response time and CPU utilization. System security is a part of operating system. Multiple users can’t access without the security code or password.3. File and disk management: The user needs to save, copy, delete, move and rename the files. The system software will handle those functions. Disk and file management is the technical task.

3.3 Application softwareThese are programs designed to solve specific problems of the user. Application software is designed to perform the practical problems experienced in life.

Application software includes most of the types of programs we use every day to get our computerized work done. Application programs are widely used in our society for entering and editing text (word processing), for entering and manipulating





numerical data (spread sheets and other business programs), and for record keeping (database management programs). These types of programs are sometimes referred to as general purpose applications.

Application software is divided into two: i.e. off-shelf and Bespoke (custom-made)

software/Tailor made application software.

Off-shelf application softwareThese are already made programs bought ‘off-the shelves’ from a software shop or vendor. It can also be defined as software that is ready-made and available to lots of people. You usually pay a license fee to use it

Off- shelf application software can further be divided into Horizontal market applications (common applications you can find on every office computer) and vertical market applications also known as specialized application programs.

Horizontal market softwareThese are software tools that are useful to almost any one in any job. These are programs you can find on almost every computer in every office. They include;

o Spreadsheets used for organization and analysis of data in tabular form.

o Word-processors used to produce text documents that are professionally laid out.

o Presentation software used for creating presentations to show to customers or staff

o Databases used for keeping customer records, sales records, appointments system

o Desktop publishing packages used for creating leaflets, posters, business cards

o Graphics packages for manipulating images that can be used at home, school or a business

o Web design application used for creating personal or business web sites o Communication software among others.

Vertical market (specialized applications)It consists of programs developed for a specific industry. Examples include Computer Aided Designs (CAD), Bakery recipes, Bridge analysis, airline ticketing, airplane wing structure, robots swivel control, electronic testing etc.




http://en.wikipedia.org/wiki/Table_(information)

http://en.wikipedia.org/wiki/Data


Bespoke (custom-made) software/Tailor made application software.

Bespoke software is written especially for you, to meet your specific business requirements.

If very specialized software is needed, a company may decide to write or order its own software. This software is called custom software. This software is developed by computer specialists or programmers. Examples may include; admission software at IUIU, loan portfolio software for Cairo bank, programming in D-base dealing in hotel operations etc.

Advantages Off-shelf application

It is relatively cheap, especially when compared to custom written softwareIt is easily available from most computer shopsIt will have been thoroughly tested so there won’t be any serious problems or bugsThere will be lots of user support i.e. books, user guides, online help and discussion forums on the Internet

Lower training costs. If it is a commonly used package, users and I.T. staff may already be familiar with it, saving on learning time and training costs. Or, there may be pre-existing training materials and courses that you can leverage.

More functionality. Off-the-shelf software often has more functionality, because the developers try to meet the requirements of as many users as possible. (There may even be functionality you didn’t realise you need!)

Upgrades. The vendor will continue to develop the software, so you will likely get upgrades for free or at a reduced cost, whereas in bespoke software you don’t get anything new unless you pay for it to be built.

The disadvantages off-shelf are:

Compromise. You may have to compromise on your requirements – it is unlikely you will find ready-made software that does everything you need it to, exactly how you want it to.

May be overly complicated. The software may include functionality that you don’t need, as it is trying to meet the different requirements of a number of users. This can make it more difficult to learn and use.





You are not in control. The vendor’s plans for the future may not always fit with your own. As a single customer amongst many, you may not be able to get the features you want implemented.

The advantages of bespoke (custom-made) softwareare: Tailored to you. The software is developed and built to meet your specific

requirements, ensuring that you get software that works exactly how you need it to and delivers the results you want.

More flexible. A bespoke system can evolve over time to match your changing requirements.

No per-user fees. If you own the software, you won’t have to extra per-user fees as your business grows.

Not tied in. You own the intellectual property, so you are not tied to a specific vendor that could potentially disappear at any time.

Competitive advantage. As your competitors won’t have the same software, it could give you a competitive edge. An effective software package can make a company work more efficiently, improve their performance and have a positive impact on customer satisfaction levels.

The disadvantages are:

Higher initial costs. It will cost more at the beginning, as you have to pay the development costs.

Takes longer. Depending on the size and complexity of the software, it may take months or even years to develop.

SENIOR TWO TERM: TWOWWW.bedesoft.org email [email protected] 0787277091




Word Processor

A word processor, or word processing program, does exactly what the name implies. It processes words.

The term "text editor" can also be used to refer to a word processing program. However, it is more commonly used to describe basic word processing programs with limited features.

MICROSOFT-WORD

Microsoft Word is a software program that is used to produce text documents that are professionally laid out.

In general Microsoft Word is a Word processor, which generally deals with text production. Simply the transfer of thoughts on to a printed matter on a piece of paper.

MS Word is a window based advanced word processor developed by Microsoft Corporation-incorporating friendly interface, for the user with an aim or specification of the required format-With simplified procedures. It comes in Microsoft OFFICE installation CD and versions include OFFICE 97, 2000, 2003 and now 2007 & 2010..

OTHER EXAMPLES OF WORD PROCESSORS

i) AmiProii) Word Stariii) Word Perfectiv) WORD Padv) Perfect writer

Getting Started with MS Word 2007

MS Word is a powerful word processor that makes it easy to create basic documents like letters and resumes. This Tech Help sheet is based on MS Word 2007 and covers the following:

Workspace overview (menus, toolbars, etc) Creating new documents and opening existing ones Moving, cutting, and copying text Simple formatting

Launching Word and Workspace Overview





To launch MS Word, either double click on the Word icon if it appears on the desktop

or click on the Windows "Start Button" > Programs > Microsoft Office > Microsoft Word.

When you launch MS Word, you'll see something like the screen below. Take a moment to familiarize yourself with the items indicated on the image.





The MS Office Button

The MS Office Button is in the top left corner of the window and provides access to open, save, and print documents.

Click on the Microsoft Office Button and then click on the desired option. Menu options with an arrow have additional choices available in the area to

the right.

Quick Access Toolbar

The Quick Access Toolbar is just to the right of the Office Button. When the cursor is over a button, the name of the button is displayed. The options available when Microsoft Office 2007 is first installed include

Save, Undo, and Redo.

The Ribbon

In Word 2007, the Ribbon is where you'll do most of your formatting and text manipulation, so take some time to explore it.





The Ribbon consists of 3 types of items.

Tabs-This is the main level and includes Home, Insert, Page Layout, etc. Groups-Each tab has several groups that show related items together Commands-A command is a button in a group or an item in a list.

Some tabs are only available when a particular item is selected. For example, the Picture Tools tab is only shown when a picture is clicked on.

To use the Ribbon:

Click on the desired tab. The commands under each tab are grouped. The name of the group is at the bottom. Some groups have a Dialog Box Launcher button which opens the dialog box

with more commands.

Creating a New Word Document

When you launch MS Word, a new document is already created for you. However, if you need to create another new document while working on an existing document, do either of the following:

Office Button: > New; select Blank Document or a template. Quick Access Toolbar, click the down arrow select new.

If you'd like some random text to work with to learn how to manipulate text, in your blank document, type: =rand() and press the Enter key. Random text will magically appear!

Opening an Existing Document

Click on the Microsoft Office Button and then click on Open. Navigate to the location of the desired file. Choose the name of the file to work with and click on the Open button.

Cutting, copying, and pasting text

Cutting, copying, and pasting text can be very convenient when you need to rearrange parts of a document. Instead of re-typing like you would have to do on a computer, you can simply select the text you want to move, cut it, and paste it in to another part of the document. If you want to use the text in several places in a document, you can use copy/paste instead of cute/paste. In order to be able to manipulate text, you'll need to be able to select it.





Selecting Text

There are several ways to select text. Use the one that is most comfortable to you and meets your needs most efficiently.

Drag selectingClick where you want to start selecting text, press the left mouse button, drag across the text, then release the mouse button where you want to end.

Shift-clickClick where you want to start selecting text, hold down the Shift key, move the cursor and then click where you want to end the selected text.

ClickingOnce to put the cursor next to a letter; Twice (double-click) to select the word; Three times (triple-click) to select the paragraph

Select AllTo select all the text in the document, Home Tab >Edit Group>Select All OR CTRL+A

Cutting and Pasting Text

Select the text to be moved. Press Ctrl X OR on the Ribbon, click on the Home tab, then in the Clipboard

group, click on the Cut button. Click where the selected text is to be moved. Press Ctrl V OR on the Ribbon, click on the Home tab. In the Clipboard group,

click on the Paste button.

Copying and Pasting Text

Select the text to be copied. Press Ctrl C OR on the Ribbon, click on the Home tab. In the Clipboard group,

click on the Copy button. Click where the selected text is to be copied. Press Ctrl V OR on the Ribbon, click on the Home tab. In the Clipboard group,

click on the Paste button.

Formatting Basics

Formatting refers generally to the appearance of the text in your document. Things like font face, font size and color, bulleted lists, etc., are all controlled through different formatting tools.





Selecting Font Size

Select the text to be changed. On the Ribbon, click on the Home tab. In the Font group, change the font and font size as desired.

o Note that you can grow and shrink font size or enter an exact number if you know what size you want to use.

Alignment

In many instances, you'll want to line your text up either to the left, center, or right of the document.

Select the text to be formatted. On the Ribbon, click on the Home tab. In the Paragraph group, click on the appropriate alignment button on the

toolbar. o Left-Text aligns to the left with an uneven edge on the right.o Center-Text aligns to the center.o Right-Text aligns to the right.o Justify-Text aligns with the even edges on the left and right by spacing

words across the page.

Creating a Bulleted List

Click in the line of the text to be bulleted. On the Ribbon, click on the Home tab. In the Paragraph group, click on the Bullets button.

The Bullets button is a toggle, which means that if you select a line of text that is already bulleted, clicking on the Bullets button will un-bullet that line.

Also notice that you can select the numbered Bullet button if you need an ordered list, too!

The Vertical and Horizontal Scroll Bars

The vertical and horizontal scroll bars enable you to move up, down, and across your window simply by dragging the icon located on the scroll bar.

The vertical scroll bar is located along the right side of the screen.

The horizontal scroll bar is located just above the status bar. To move up and down your document, click and drag the vertical scroll bar up and down. To move back and forth across your document, click and drag the horizontal scroll bar back and





forth. You won't see a horizontal scroll bar if the width of your document fits on your screen.

The Status Bar

The Status bar appears at the very bottom of your window and provides information such as the current page and the number of words in your document.

You can change what displays on the Status bar by right-clicking on the Status bar and selecting the options you want from the Customize Status Bar menu.

You click a menu item to select it. You click it again to deselect it. A check mark next to an item means it is selected.

Understanding Document Views

In Word 2007, you can display your document in one of the five views: Draft, Web Layout, Print Layout, Full Screen Reading, Outline Layout.

Draft ViewDraft view is the most frequently used view. You use Draft view to quickly edit your document.

Web LayoutWeb Layout view enables you to see your document as it would appear in a browser such as Internet Explorer.





Print LayoutThe Print Layout view shows the document as it will look when it is printed.

Reading LayoutReading Layout view formats your screen to make reading your document more comfortable.

Outline ViewOutline view displays the document in outline form. You can display headings without the text. If you move a heading, the accompanying text moves with it.

You should use Draft view for these lessons. Before moving ahead, make sure you are in Draft view:

1. Click the View tab.2. Click Draft in the Document Views group. When the Draft option is selected it

appears in a contrasting color.

Click

During the lessons that follow, you will be asked to "click" items and to choose tabs. When asked to click:

1. Point to the item. 2. Press your left mouse button once.

If you are asked to double-click an item:

1. Point to the item. 2. Quickly press your left mouse button twice.

If you are asked to right-click:

1. Point to the item.2. Press your right mouse button.

If you are asked to choose a tab, click the tab.





Checking the Spelling in a Document

Word has a built-in Spell Checker to check for misspelled words, duplicate words, and irregular capitalization in documents, parts of documents, and text entry boxes. When Spell Checker finds a misspelled word, you can replace it with the suggested word, edit the word manually, or skip the word. You can also define a replacement for the word by adding it to a user word list.

In an open document, locate the Word Ribbon, click on the Review tab. In the Proofing group, click on Spelling & Grammar. The word in question will be shown in red in the context of the sentence. Choose one of the following:

o Ignore Once - Don't replace the word.o Ignore All - Don't replace the word and don,t stop if the same

problem is encountered again.o Add to Dictionary - Add the word to the dictionary. This is dangerous

because it changes the Spelling Dictionary.o Change - Change the word in red to the selected word in the

Suggestions box.o Change All - Change all occurrences of the word in the document to

the selected word in the Suggestions box.o AutoCorrect - Sets the computer to automatically help with spelling.

Note-automatic spelling must be turned on in Options. Click on the Close button.

Note that if no words are recognized as being misspelled and no grammar errors are encountered, the window does not open.

Saving a Document

Click on the Microsoft Office Button and then click on Save As. By Default, Word saves the documents to the My Documents folder as a .docx

file. You can navigate to a different location if you want to save the file somewhere else, like on a flash drive.

Click on the Save button.

Printing the Document

In order to print a document, the computer you're using must be connected to a printer. If you're using a computer at a library or other computer center, ask to makee sure there is a printer available before you count on printing. Some libraries




http://coloradovirtuallibrary.org/content/storing-your-files


and other computer centers will charge a per-sheet fee for printing, so make sure you're prepared for that, too.

Click on the Microsoft Office Button and then choose Print. Check to make sure the correct printer is chosen Click on the down arrow in the Printer section and choose a printer. In the Page Range section, decide which pages to print. (All, the current page,

or a range of pages.) In the Copies section, indicate how many copies. Click on the OK button.

SENIOR TWO TERM: THREEPresentation softwareA presentation program is a software package used to display information in the form of a slide show.Examples of presentation software:

Microsoft PowerPoint

Adobe Presenter 8

Apple Keynote,

Apple Keynote

Corel Presentations

Harvard Graphics

Lotus Freelance Graphics

Slide Rocket

SlideWiki USES OF PRESENTATION SOTF WARE

1. Used for designing and branding.2. Used for training like in seminars3. Used for advertising.4. Used to draw organization charts.




http://en.wikipedia.org/wiki/Slide_show

http://en.wikipedia.org/wiki/Software


INTRODUCTION TO POWER POINTPowerPoint is application software used for slide preparation and presentation.Terms associated with power pointSlide. The place provided to design the presentation where we can type the text and insert the pictures etc to make them more interactive.Or a slide is a displayed screen or a page during a presentation.Slide Layout: This is the out look of the slide Or the specific arrangement of text and images on a slideDesign Template: The specific “look” of a slide or group of slides. A design template can be very basic - with black text on a white background - or it can be very colorful and complex. Typically, PowerPoint presentations have the same design template for all slides, although it is possible to select a different design template for each slide. Later, I’ll show you how to select different design templates.Slide Show: The way a presentation appears when you are presenting it. When you display your slides in a slide show, the slides typically take up the whole screen. Slide show is the full screen view of slidesSlide Transition: A slide transition refers to the visual movements as a slide changes from one to another.Animations: These are visual effects applied to individual items on the slide such as graphics and bullet points.

FEATURES OF THE PRESENTATION SOFT WARE

2 Insert slide feature; This allows the user to insert a slide any where in the presentation either at the beginning ,middle or at the end

3 Deletion of inserted slide; This allows the user to erase any information on the inserted slide.

4 Cut and paste of slides; This can be done to change the position of a slide removing the slide from its own position to another position .It allows animations and sound manipulation.

5 Font specification6 Spelling checker.

STARTING UP POWERPOINT 2007

Click on the Start button, located in the lower left corner of the Windows task bar.

Point to All programs, click Microsoft Office. Select Microsoft Office PowerPoint 2007. PowerPoint 2007 will open displaying a blank the new PowerPoint

environment slide.





SOME PARTS OF MS POWERPOINT 2007

Quick Access Tool Bar: Quick Access Toolbar is located to the right of the Microsoft Office Button. By default the Quick Access Tool Bar displays the Save, Undo, and Repeat buttons and is used for easy access to frequently used commands

Title Bar: A horizontal bar at the top of an active document. This bar displays the name of the presentation and application. At the right end of the Title Bar, as in previous versions is the Minimize, Restore and Close buttons.

Ribbon: is located in the upper-left corner of the window. The Ribbon exposes most of the feature that use to be hidden in File Menus. The Ribbon makes it easier to see and find commands to format your document.

Tip: The Ribbon can be reduced to a single line of tabs by pressing CTRL + F1.

Microsoft Office Button: A button that provides access to menu commands in. Here is where you will find commonly known features such as New, Open, Save, Print and Recent Documents.

Tab: An area on the Ribbon that contains buttons organized in groups. The default tabs are Home, Insert, Design, Animations, Slide Show, Review and View.

Slide Pane: Workspace to create, edit or format, slides. View Toolbar: A toolbar that enables, adjusts, and displays different views of a presentation’s content.

Notes Pane: Here you type notes that apply to slide. You can print your notes and refer to them when you give your presentation or handout to your audience.

Status Bar: A horizontal bar at the bottom of an active window that gives details about the active presentation

Slides and Outline Tab Pane:

Slide tab allows you to view slides thumbnail-sized making it easy for you to navigate through your presentation and to see the effects of any design changes.

You can also easily rearrange, add, or delete slides here.

Outline tab is where you can start writing content, Capture ideas, plan how to present them, and move slides and text around. The Outline tab shows your slide text in outline form. Slide Pane: Status Bar: Notes Pane View Toolbar:

The Home tab: is organized in six groups mainly related to slide layout and formatting: Clipboard, Slides, Font, Paragraph, Drawing, and Editing. For example,





the Home tab will allow you to quickly create a new slide Choose a layout, add and format text and shapes

The Insert tab: is organized in five groups: Tables, Illustrations, Links, Text, and Media Clips. Here you find all objects you would include with your slides, such as, tables, text boxes, pictures, sounds, diagrams, hyperlinks, charts, headers and footers

The Design tab: is organized in three groups: Page Setup, Themes, and Background.

The Themes group command allows you to completely change the look of your presentation. This includes the Colors, Background, Fonts.

The Animations tab: is organized in three groups: Preview, Animations, and Transition to this Slide. Here is where you find the tools to set the animating effects to your presentations and slide transitions.

The Slide Show tab: is organized in three groups: Start Slide Show, Setup, and Monitors. Here is where you prepare you presentation, add narration, choose which slide to start with and set up the view when multiple monitors are involved.

The Review tab: is organized in three groups: Proofing, Comments, and Protect. Here is where you will find your spelling and grammar checker, in addition to this when you have someone review your presentation this is where comments can be added and addressed.

The View tab: is organized into six groups: Presentation Views like Normal view: This is the main working window in the power point. Slide sorter view: is the window in power point that displays thumb nail version of all your slides arranged in horizontal row. Slide show view takes up the full computer screen, like an actual slide show presentation. In this full-screen view, you see your presentation the way your audience will, Show/Hide, Zoom, Color / Grayscale, Window, and Macros. Here you can change the display of your presentations, make a quick switch to Notes Page view, turn on gridlines, or arrange all your open presentations in the window. Live Preview Temporarily applies formatting on select text or objects whenever a formatting command is hovered. This allows you to quickly see how the formatting options will look in place before they are made. Live Preview

CREATING A NEW PRESENTATION





1. Click Microsoft Office Button

2. Click New, New presentation screen appears

3. Double-Click on Blank Presentation

OPENING AN EXISTING PRESENTATION

1. Click the Microsoft Office Button.

2. Click Open.

3. In the Open dialogue box, navigate to the open, and then double-click the file.

CREATING A NEW SLIDE

1. On the Home tab, in the Slides group, click New Slide.

CHOOSING A LAYOUT FOR A NEW SLIDE

1. From the Outline and Slides tab Pane, click on the slide you are selecting a new layout for.

2. On the Home tab, in the Slides group, click Layout.

3. Click Layout Style of your choice.

ADDING TEXT TO A SLIDE

Slide layouts contain placeholders. The dotted border represents placeholders; just click inside the border and you can add text or insert objects. The slide’s layout will determine the position and size of placeholders.

1. Click inside a text placeholder.

2. Type or Paste the Text or object.

Note - If your text exceeds the size of the placeholder, PowerPoint reduces the font size and line spacing incrementally as you type, to make the text fit.

DELETING A SLIDE





1. Right-click the slide that you want to delete.

2. Click Delete Slide.

SELECTING A THEME FOR YOUR PRESENTATION

On the Design tab, in the Themes group, click the document theme that you want, or click more to see all available document themes.

TIP - You can apply a theme to all slides at any given point in time. Whenever you feel like changing the theme, you can.

INSERTING OBJECTS INTO YOUR PRESENTATIONS / INSERTING PICTURES TO YOUR PRESENTATION

1. From Insert Tab, in Illustrations Group, click Picture.

2. Double-Click Folder where picture is stored

3. Double-Click on picture you want to insert

INSERTING CLIP ART INTO YOUR PRESENTATION

1. From Insert Tab, in Illustrations Group, click Clip Art.

2. Search field will appear. Enter keyword in Search for field.

3. Click Go.

4. Results appear, click on image you choose then drag image into your open slide.

Note - Once Picture or Clip Art is inserted, if you want to resize it or give it special effects. Click on the image and the Picture Tools appear on the Ribbon. Click the Format tab, and use buttons and options there to work with the picture.

INSERTING SHAPES INTO YOUR PRESENTATION

1. Home tab, in the Drawing group, click Shapes. Or from the Insert tab, click Shapes.

2. After selecting the desired shape, drag your mouse across the slide to draw the shape.





Note - Once your shape is inserted, if you want to resize it or give it special effects. Click on the shape and the Drawing Tools appear on the Ribbon. Click the Format tab, and use buttons and options there to work with the shape.

ADD TEXT TO A SHAPE

Shapes such as squares, circles, callouts, balloons, and block arrows can contain text. When you type text into a shape, the text attaches to the shape and moves and rotates with it.

To add text that becomes part of a shape, select the shape and then type or paste the text.

INSERTING CHARTS INTO YOUR PRESENTATION

Inserting Charts created in Excel

1. In Excel, select the chart by highlighting the cells.

2. From the Home Tab Clipboard group, click Copy.

3. In PowerPoint, click in the placeholder on the slide where you want to insert the chart. 4. On the Home tab, in the Clipboard group, click Paste.

Inserting a Chart from within PowerPoint

1. In PowerPoint, click the slide where you will insert chart.

2. On the Insert tab, in the Illustrations group, click the type of chart you want to use.

3. In the Insert Chart dialog box, click chart, then click OK.

Office Excel 2007 opens in a split window and displays sample data on a worksheet.

In Excel, to replace the sample data, click a cell on the worksheet. 5. Type your data that you want.

Inserting SmartArt Graphics

On the Insert tab, in the Illustrations group, click SmartArt.

1. In the Choose a SmartArt Graphic dialog box, click the type and layout that you want.





2. Enter your text by doing one of the following:

a. Click in a shape in your SmartArt graphic, and then type your text.

b. Click Text in the Text pane and then type or paste your text.

c. Copy text from another program, click Text, and then paste into the Text pane. A SmartArt graphic is a visual representation of your information that you can quickly and easily create, choosing from among many different layouts, to effectively communicate your message or ideas.

SAVING A NEW PRESENTATION

1. Click on Microsoft Office Button.

2. Click Save-As.

3. In the File name type the name of the presentation.

4. Click Save.

Note - If you need to save in a different location click the down arrow on the right end of the save in box and then choose your location.

CHANGING THE ORDER OF THE SLIDES

1. In the Outline and Slides tab Pane, click the Slides tab.

2. Click on the slide thumbnail that you want to move, and then drag them to their new location.

Tip - To select multiple sequential slides, click the first slide, and then hold down SHIFT while you click the last slide that you want to select. To select multiple non-sequential slides, hold down Control while you click each slide that you want to select.

INSERTING OBJECTS INTO YOUR PRESENTATION

From the Animation Tab PowerPoint 2007 enables you to easily apply animation effects to make your presentation more appealing. You can choose to have your slides fade-in or dissolve.

In addition to this, you can control the timing of the transition from slide to slide and how the transitions will occur.





Just go to the Animation tab, click on the slide you wish to add the animation and select an option. The finishing tasks for creating your presentation are located on the Slide Show and Review Tabs.

Use the Slide Show tab to create narration, set-up views, and multiple monitors. The Review tab is for spell check and reviewing comments.

KEYBOARD SHORTCUTS FOR PRESENTATION ACTIVITY SHORTCUT

Start a presentation from the beginning. F5 Perform the next animation or advance to the N, Enter, Page Down, Right

Arrow, next slide. Down Arrow, Or Spacebar Perform the previous animation or return to P, Page Up, Left Arrow, Up

Arrow, Or the previous slide. Backspace Go to slide number. Number+Enter Display a blank black slide, or return to the B Or Period presentation from a

blank black slide. Display a blank white slide, or return to the W Or Comma presentation from

a blank white slide. Stop or restart an automatic presentation. S End a presentation. Esc Or Hyphen Erase on-screen annotations. E Return to the first slide. 1+Enter Display the shortcut menu. Shift+F10 Go to the first or next hyperlink on a slide. Tab The Ribbon can be reduced to a single line of CTRL+F1 tabs Print preview CTRL+F2 To close the presentation CTRL+F4 To restore the presentation CTRL+F5 To minimize the presentation CTRL+F9 To duplicate the image Select the object and press CTRL+D To group the objects first select what you want to group and then press

CTRL+G

Qualities of a Good Presentation1. Establish a uniform/single look for the presentation.2. Avoid fancy font





3. Keep animations & transition consistent4. Include only one main concept per slide5. Combaining photos, charts and videos with text will keep your audience

interested.6. Include atitle page with ypur name, contact, date and session topic for the

presentation.

Making a good presentation can be easy if you include the following elements:Element 1:Simple slides, with no more than one concept per page, and no more than 25-30 words per page.

Good Not so good

Element 2:Text and images should be kept within a reasonable distance from the edges of the slide. This prevents the slide from looking over-crowded. Good Not so good

Element 3:





Slides that are easy to read. Avoid flashy color schemes, fonts, and animation. These features should complement a presentation, and not be the presentation itself. Good Not so good

NOTE: Choose "Slide Design - Color Schemes" from the task pane menu to see a variety of pre-designed schemes you can apply to your slides.

SENIOR THREE TERM: ONETOPIC 6: SYSTEM START-PU AND CONFIGURATION6.1. COMPUTER BOOTINGBooting means starting a computer. There are two main ways of booting a computer i.e. cold booting and warm booting.Types of bootingCold booting is the starting of a computer from its off state from the mains. Involves switching on a computer right from the main power supply, stabilizer or uninterruptible power supply (UPS), the system unit and the monitor.Warm booting is the restarting of a computer by either the restart button or pressing the following keys together and then releasing them at the same time Ctrl+Alt+Delete. Normally, a computer is warm booted after it hanged i.e. not responding to any command

The booting processThe Power on Self Test (POST) is the first of several checks performed by the PC’s ROM BIOS. These tests check that basic components of the PC are present and working correctly. An error message or a series of beeps indicating any hardware problems will be sounded. Normally, the PC will beep once to inform the user that the checks were completed without a problem being identified





6.2. System configurationSystem specifications

COMPUTER SPECICFICATIONSThere are several computer systems available on the market that can be acquired as office or personal computers. However, depending on the purpose and period for which the computer will be used then care should be taken when choosing such a computer.What to consider when purchasing a computer

The computer platform. Here you consider which type of microcomputer would you like to buy it Toshiba, Macintosh, hp or IBM

Hard disk. The choice of a hard disk mainly depends on several factors ie the tasks that the computer will be used whether the operations will keep on increasing requiring more memory or will be constant.

Display device. Currently there are two types of displays ie CRT and LCD. CRT occupy bigger space and consumes a lot of power whereas LCD are better

Expansion slots. Expansion slots are found on desktop computers which provide space for expansion cards (add-on-cards) that might have ports for additional peripheral components like TV cards

Sound Card. When planning to work with multimedia packages, especially sound, an appropriate card has to be sought of.

Modems. These are used to transmit data to and from the computer. So you have to consider whether the modem is capable of both wireless and wire internet connection

PC Casing. This refers to the physical structure of the box that contains and shields the working components of a computer ie do you need a tower casing or standard desktop casing

PC case molding. Which sharp and design do you want Cost

COMPUTER PARTSPARTS OF A COMPUTER SYSTEM





PARTS OF A COMPUTER

The monitor: This is a device which shows/gives the soft copy of the data/information in the computer. Monitor

There are two basic types of monitors: CRT (cathode ray tube) monitors and LCD (liquid crystal display) monitors. Both types produce sharp images, but LCD monitors have the advantage of being much thinner and lighter. CRT monitors, however, are generally more affordable.

Keyboard. It’s an input device that converts letters and other characters into electric signals readable by the processor. It has a type writer area, function keys, cursor movement keys and numerical keypad. It’s a device which enables a computer user to communicate to the computer system.Mouse. This is a hand held pointing device which is used to point, select, move and draw object in the computer screen. Examples of mice include: codeless, touch pad (touch tone pad), mouse stick.Printers. These are devices which gives a hard copy of the soft copy of the data or information held in the computer. Printers are output devices that produce text and graphics on paper. The two main types of printers are inkjet printers and laser printers. Inkjet printers are the most popular printers for the home. They can print in black and white or in full color and can produce high-quality photographs when used with special paper. Laser printers are faster and generally better able to handle heavy use.


Monitor

Keyboard

Mouse

Printer

Speaker

Computer Case (Processor inside)

Floppy Disk Drive

CD-ROM/DVD Drive




Speakers. Speakers are used to play sound. They may be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer.

System unit The system unit is the core of a computer system. Usually it's a rectangular box placed on or underneath your desk. Inside this box are many electronic components that process information. The most important of these components is the central processing unit (CPU), or microprocessor, which acts as the "brain" of your computer. Another component is random access memory (RAM), which temporarily stores information that the CPU uses while the computer is on.

CD/DVD DriveThis a computer hardware device that reads compact discs and DVDsHard driveBASIC PARTS OF A COMPUTERMonitorMouseKeyboardSystem unitCD/DVD Drive

CONNECTION AND SETUP OF HARDWARE COMPONENTS

FORMATTING DISKS

6.3. SYSTEM INSTALLATION

Installing operating systemsInstalling application and utility softwareUninstalling softwareInstalling device drivers

6.4. Computer troubleshooting

This is any form of problem solving on a computer system often applied to repair failed products or processb. state any three ways how to troubleshoot a computer (3mks)





7. restarting of the computer8. check the electric power cables weather connected well9. listen for unusual sounds10. look inside the system unit for wires that are not plugged11. disconnect peripheral devices e.g. printers and restart

System freeze and bugsSystem performance

7.1. Introduction to computer communicationDefinition of terminologies





Importance of computer communicationLimitation of computer communication7.2. Networks

What is a Network?

A network consists of two or more computers/computing devices that are linked in order to share resources, exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.

TYPES OF NETWORKS

The three basic types of networks include: LAN, MAN and WAN.

LOCAL AREA NETWORK (LAN)

A network is said to be Local Area Network (LAN) if it is confined relatively to a small area. It is generally limited to a building or a geographical area, expanding not more than a mile apart to other computers.

LAN configuration consists of:

A file server - stores all of the software that controls the network, as well as the software that can be shared by the computers attached to the network.

A workstation - computers connected to the file server (Mac or PCs). These are less powerful than the file server

Cables - used to connect the network interface cards in each computer.

Types of LANs / Network models

The two major types of network operating systems are:

Peer-to-Peer Client/Server

Peer-to-Peer




http://fcit.usf.edu/network/chap6/chap6.htm#client

http://fcit.usf.edu/network/chap6/chap6.htm#peer


Peer-to-peer network operating systems allow users to share resources and files located on their computers and to access shared resources found on other computers.

However, they do not have a file server or a centralized management source (See fig. 1).

In a peer-to-peer network, all computers are considered equal; they all have the same abilities to use the resources available on the network. Peer-to-peer networks are designed primarily for small to medium local area networks. AppleShare and Windows for Workgroups are examples of programs that can function as peer-to-peer network operating systems.

Fig. 1. Peer-to-peer network

Advantages of a peer-to-peer network:

Less initial expense - No need for a dedicated server. Setup - An operating system (such as Windows XP) already in place may only

need to be reconfigured for peer-to-peer operations.

Disadvantages of a peer-to-peer network:

Decentralized - No central repository for files and applications. Security - Does not provide the security available on a client/server network.

Client/Server

Client/server network allows the network to centralize functions and applications in one or more dedicated file servers (See fig. 2).





The file servers become the heart of the system, providing access to resources and providing security. Individual workstations (clients) have access to the resources available on the file servers. The network operating system provides the mechanism to integrate all the components of the network and allow multiple users to simultaneously share the same resources irrespective of physical location. Novell Netware and Windows 2000 Server are examples of client/server network operating systems.

Fig. 2. Client/server network

Advantages of a client/server network:

Centralized - Resources and data security are controlled through the server. Scalability - Any or all elements can be replaced individually as needs

increase. Flexibility - New technology can be easily integrated into system. Interoperability - All components (client/network/server) work together. Accessibility - Servers can be accessed remotely and across multiple

platforms.

Disadvantages of a client/server network:

Expense - Requires initial investment in dedicated servers. Maintenance - Large networks will require a staff to ensure efficient

operation. Dependence - When server goes down, operations will cease across the

network.

Client-server model





METROPOLITAN AREA NETWORK (MAN)

Metropolitan Area Network (MAN) covers larger geographic areas, such as cities. Often used by local libraries and government agencies often to connect to citizens and private industries

WIDE AREA NETWORK (WAN)

Wide Area Networks (WANs) connects larger geographic areas, such as London, the UK, or the world. In this type of network dedicated transoceanic cabling or satellite uplinks may be used.

Advantages of computer Networks

Speed. Networks provide a very rapid method for sharing and transferring files. Without a network, files are shared by copying them to floppy disks, then carrying or sending the disks from one computer to another. This method of transferring files (referred to as sneaker-net) is very time-consuming.

Cost. Networkable versions of many popular software programs are available at considerable savings when compared to buying individually licensed copies. Besides monetary savings, sharing a program on a network allows for easier upgrading of the program. The changes have to be done only once, on the file server, instead of on all the individual workstations.





Security. Files and programs on a network can be designated as "copy inhibit," so that you do not have to worry about illegal copying of programs. Also, passwords can be established for specific directories to restrict access to authorized users.

Centralized Software Management. One of the greatest benefits of installing a network at a school is the fact that all of the software can be loaded on one computer (the file server). This eliminates the need to spend time and energy installing updates and tracking files on independent computers throughout the building.

Resource Sharing. Sharing resources is another area in which a network exceeds stand-alone computers. Most schools cannot afford enough laser printers, fax machines, modems, scanners, and CD-ROM players for each computer. However, if these or similar peripherals are added to a network, they can be shared by many users.

Electronic Mail. The presence of a network provides the hardware necessary to install an e-mail system. E-mail aids in personal and professional communication for all school personnel, and it facilitates the dissemination of general information to the entire school staff. Electronic mail on a LAN can enable students to communicate with teachers and peers at their own school. If the LAN is connected to the Internet, students can communicate with others throughout the world.

Flexible Access. School networks allow students to access their files from computers throughout the school. Students can begin an assignment in their classroom, save part of it on a public access area of the network, then go to the media center after school to finish their work. Students can also work cooperatively through the network.

Workgroup Computing. Workgroup software (such as Microsoft BackOffice) allows many users to work on a document or project concurrently. For example, educators located at various schools within a county could simultaneously contribute their ideas about the new curriculum standards to the same document and spreadsheets.

Disadvantages of computer Networks

Expensive to Install. Although a network will generally save money over time, the initial costs of installation can be prohibitive. Cables, network cards, and software are expensive, and the installation may require the services of a technician.

Requires Administrative Time. Proper maintenance of a computer network requires considerable time and expertise. Many schools have installed a network, only to find that they did not budget for the necessary administrative support.





File Server May Fail. Although a file server is no more susceptible to failure than any other computer, when the files server "goes down," the entire network may come to a halt. When this happens, the entire school may lose access to necessary programs and files.

Cables May Break. The Topology chapter presents information about the various configurations of cables. Some of the configurations are designed to minimize the inconvenience of a broken cable; with other configurations, one broken cable can stop the entire network.

Server faults stop applications being available Network faults can cause loss of data. Network fault could lead to loss of resources User work dependent upon network System open to hackers Decisions tend to become centralised Could become inefFicient Could degrade in performance Resources could be located too far from user

Forms of data transmission• Defns.

• Advantages and disadvantages

Network setup and configuration

SENIOR THREE TERM: TWOINTRODUCTION TO SPREADSHEET

A spreadsheet is an interactive computer application program for organization and analysis of data in tabular form.

Features of spreadsheet softwareWWW.bedesoft.org email [email protected] 0787277091



http://en.wikipedia.org/wiki/Table_(information)

http://en.wikipedia.org/wiki/Data

http://en.wikipedia.org/wiki/Computer_application


Use of spreadsheetExamples of spreadsheetMicrosoft excel, Lotus 1-2-3, Corell quarto, VisiCalc, Supercalc etc

MS EXCEL.

Excel is calculation/mathematics oriented application software.

It is used to prepare payroll, inventory and other accounts related statements.

It is a large electronic spreadsheet (table) made of rows and columns, so this is also called spreadsheet program.

Screen elements in excel:1. Menu bar: used to display the menu names, which contains number of

commands. E.g. home, insert, page layout etc.2. Tool button: frequently used commands are made into buttons for easy

access.3. Toolbars: collection of tool buttons of same category. E.g. standard and

formatting toolbars.4. Formula bar: used to display the contents or the formula of the active cell.5. Cell reference area. Used to display the address of the active cell.6. column heading: used to display the name of the column (E.g. A,B,C…IV)7. row heading: used to display the number of rows (E.g. 1,2,3,….16394)8. Sheet: made up columns and rows.9. One sheet contains 65536 Rows and 256 Columns.10. Sheet tab: used to display the name of the sheet. E.g. sheet1, sheet2 etc.11. Workbook: is the name of the excel file which contains 16 sheets by default.

We can increase or decrease the number of sheets in a workbook.12. Cell: cell is an intersection of a column and row.13. Cell address: each cell is represented by a unique code is called cell address.

It is made up of the column name and row number of that cell. E.g. A1, F40 etc.

Data types in Excel: normally four types of data types are used in excel.

1. Character /text data type: any combination of numbers, spaces, symbols and non-numeric characters will be used. The default alignment is of the character data is left

2. numeric data type:Contains only numbers





A numerical data can contain only the following characters.0 1 2 3 4 5 6 7 8 9 $ % etcThe default alignment is right.

3. Date data type:The data which treated as a date.When you type the date, use the month, date, year format and separate by a slash (/) or a hyphen (-)The default alignment is Right.4. Time data type;The data which consider as a timeUse+: to separate the hour, minute, second.Use a or p to indicate AM or PM (leave a single space before a or p)The default alignment is Right.

Microsoft Excels operators

Arithmetical operators Comparison operators Logical operators

Arithmetical operators

Operator Description+ (plus) Addition-(minus) Subtraction* (asterisk) Multiplication/ (forward slash) Division^ (curate) Exponential% (percent) Percent

Comparison operators

Operator Description< Less than> Greater than= Equal to< > or Not equal to





>= or => Greater than or equal to

Logical operators

Operator DescriptionAND Logical and returns true if both

expressions are trueOR Logical or returns true if either of the

expressions is true.NOT Logical not, returns false if expression

is true and true if expression is false.( ) Parenthesis for groupingTRUE Returns logical value trueFALSE Returns logical value false

To do calculation in excel Use the ‘=’ symbol at first in the cell. Use the cell addresses to calculate e.g. A1 or B1 Use the appropriate operators to do the calculation e.g. =A5+D6 or

(AS*F16) / 10 etc.To add the numbers

Select the cells that contain the numbers. (And leave a blank cell at the end to place the total)

Click Auto sum button on the standard Tool bar.

Change colour of the cell content Select cells. On the Format menu, click cells …(Ctrl+1) Click Font Tab and choose the Colour from the colour list. The click Ok.

Change Font formatting of the cell content Select the cells On the Format menu, click cells ….(Ctrl+1) Click Font Tab. Change the Formatting ( font name, font style, font size, underline style,

superscript, subscript etc) Click OK to accept the changes.

Change Background colour of cells Select the cells to be formatted. On the Format Menu, click cells ….(Ctrl+1) Click Patterns Tab. Choose the cell shading colour.





Select the pattern from the pattern list. Then click Ok.

Apply Borders to cells Select the cells you want to add borders to. On the Format menu, click cells ….(Ctrl+1) Then click Border Tab. Choose the colour of the line. Click the line style you want, and then click a button (Left, Right, Top and

Bottom etc) to indicate the border placement. Click Ok.

Change Horizontal and Vertical Alignment Select the cell/cells you want to format. On the Format menu, click cells. To change horizontal alignment, select the alignment (left, centre, right etc)

from the alignment list. To change the vertical alignment, select the alignment (top, centre, bottom

etc) from the alignment list. Then click ok to accept the changes.

Merge cells to span several columns (centre across columns) Select the cells you want to merge. To merge cells in a row and centre the cell contents,

Click Merge and centre button on the Formatting toolbar orOn the Format menu, click cells, click alignment tab, and select center across selection from Horizontal listThen click Ok.Wrapping the text (Breaks text into multiple lines in a cell)

Select the cells you want to format. On the format menu, click cells…(Ctrl+1) Click alignment tab. Under text control, select the wrap text check box. Click OK to get the result.

FUNCTIONS

Functions are the pre defined formulas used in excel.Most frequently used functions and their uses are:

Name of the function Example Use of the function=sum(cell range) = sum (A1:A40) To calculate the total of

numbers= Average(cell range) = Average (B1:B40) To find out the average of

the numbers in the range.

=Max (cell range) = Max (C1:C40) To get the maximum





number from the given range

=Min(cell range) = Min (D1:D40) To get the minimum number from the given range.

= Count(cell range) =Count (A1..A40) To count the cells containing numbers.

= Now() =Now() To display the current date and time.

=Today() = Today() To display current date= Weekday(cell address) = Weekday(A5) To display the day of the

week.= Sqrt(number) =Sqrt(25) Returns square root of

the number. Sqrt(25) returns 5.

SENIOR THREE TERM: THREETOPIC 9: WEB DESIGNING9.1. Introduction to the web design

SENIOR FOUR TERM ONETOPIC 10: DATABASES10.1. Introduction to databases





A database is a collection of arranged data in a way that allows access, retrieval, and use of the data. Sometimes referred to as database management systems (DBMS)

A database is an organized collection of data.Database is a collection of records stored for a particular purpose. The data in a database are arranged in columns and rows.

Database software tools are primarily used for storing, modifying, extracting, and searching for information within a database.

Features of a databaseImportance of a databaseLimitation of a database

EXAMPLES OF DATABASE SOFTWARE INCLUDE:

Microsoft accessMicrosoft visualBorland dBaseLotus ApproachCorel paradoxClaris file maker pro etcMySQLOracleFileMaker.

Properties of objectsAccess is an object oriented application — that is, it is made up of different components called objects. Tables, fields, forms, reports and queries are a few examples of objects in an Access database system.

Table.is a MS access object where data is stored in a database. In Access, data is stored in tables. A table is a set of columns and rows, where each column referred to as a field. Each value in a field represents a single type of data. Each row of a table is referred to as a record.Query. Is a MS Access object used to retrieve specific data from your database and to answer questions about your data. For example, you can use a query to find the names of the employees in your database who live in a particular state.Form. Ms access object that gives you the ability to choose the format and arrangement of fields. You can use a form to enter, edit, and display data.Report. Ms access object used to organize or summarize your data so you can print it or view it on screen. You often use reports when you want to analyze your data or present your data to others.




http://www.webopedia.com/TERM/D/database_management_system_DBMS.html


Macros. Macros give you the ability to automate tasks. You can use a macro to add functionality to a form, report, or control.Modules. Like macros, modules give you the ability to automate tasks and add functionality to a form, report, or control. Macros are created by choosing from a list of macro actions, whereas modules are written in Visual Basic for Applications.

An object has certain characteristics associated with it, known as properties e.g. its name, size, color etc. The properties of an object can usually be inspected and altered.

Right-clicking an object with the mouse generates a shortcut menu to its list of properties, along with a list of the operations that may be carried out on it.

There are some common terms associated to databases that include the following.

i) Field

In a database, a field is the entire column that contains similar data items for example, the names column that contains each individual’s name is a field. It also applies to those of sex, district and salary. Therefore these are referred to as the sex field, the name field, district field and salary field respectively.ii) Records

A record is a set of entire data items in a row. In the above table if for example we consider the data items in the second row, it contains Martin in the names field, m in the sex field, Kampala in the district field and 120,000 in the allowance field. All this information can be described as a record that pertains to Martin.iii) Field names

A field name is the title of a particular column (field). For example the titles; names, sex, district, and allowance are field names. They are also referred to as the field labels.iv) Data types

A data/field type specifies the format to which the data items are stored. Different data items are stored differently in a database. For example, not all numerals are numeric data types.Microsoft Access supports up to nine different types of data. These could be text, memo, number, data/type, currency, yes, no, OLE object, auto number, lookup or hyperlink field. The table below summarizes the implications of each of these fields.

Field Type Data StoredAuto Number A number that is automatically assigned incrementally or

randomly to a particular record and decimal place





Currency A numeric field that is automatically assigned a currency sign, thousands separator and decimal places.

Date/time A date or time data types you can change the appearance of each from the general tab.

Hyperlink Stores data types like internet address (e.g. www.cnn.com)

Text Any characters that will not be used for calculations for example phone numbers

Lookup wizard Stores values that are from an external table, query, or a list of specific values

Memo Whole sentences of up to 64,000 characters in length including spaces

Numbers Any numerals that may be used in calculations for example amounts.

OLE Any linked object like a picture, sound, document or photograph.

Yes/No A logical field that will need only a yes or a no, true or false, on or off

v) Field properties

A field property is the specific characteristic of a particular field. Field properties are specified from the general tab on the data-table structure. They include field characteristics like field size, caption, format, decimal places, and others. Field properties change depending on the type specified. The table below summarizes some important field characteristics/properties.

Field property ImplicationAllow zero length If set to yes, even an empty string will be accepted as a valid

entry in this fieldCaption Specifies a different name to be used as a field label instead

of the specified field nameDecimal places Specifies the number of decimal places the figures should

haveDefault value Specifies the data entry value to be entered automatically for

each field unless changedField size Specifies the maximum length of characters (including

spaces) any data item in this field should have.Format Specifies the appearance of any data item in that particular

field samples of the supported formats are normally on the drop-down list box that appears when you click in the format box

Indexed Specifies whether the data in this field should be listed chronologically and whether to allow duplicate data item.




http://www.cnn.com/


Required If set to yes, this field cannot be set left blank during data entry.

Input mask Specifies a specific template for entering data items in a particular field.

Validation Rule/Validation Text

.

The Validation Rule property is used in conjunction with Validation Text to specify requirements for entered data. The rule sets the conditions and the text specifies the warning message that will be issued if the conditions are breached. For example, you could specify that numbers entered intoa field must be in the range 1-500 and set up a message such as “The value entered must be between 1 and 500”, which will be displayed when a value outside this range is entered.

Introduction to Microsoft Access 2007IntroductionA database is a collection of information that's related. Access allows you tomanage your information in one database file. Within Access there are fourmajor areas: Tables, Queries, Forms and Reports• Tables store your data in your database• Queries ask questions about information stored in your tables• Forms allow you to view data stored in your tables• Reports allow you to print data based on queries/tables that you havecreated

Creating a Database1) Start Access





2) Select Blank Database3) In the File Name field enter a name for the database4) Click Create2Microsoft Access automatically creates a new table in the database calledTable1. This is a temporary name until the table is saved.





Understanding the ViewsThere are 2 basic views when you work in a table: Design View and DatasheetView. Design View is used to set the data types, insert or delete fields, and setthe Primary key. Datasheet View is used to enter the data for the records. Bydefault, Access places you in Datasheet View.To Switch to Design view:1) Click the View button on the Home Ribbon2) Type a name for the table3) Click OK

Before proceeding, it is important to understand common Microsoft Access DataTypes. (Explained in the table below)

To Enter Fields in a Table:1) Type a name for the first field in the table2) Press Enter3) Select a data type4) Press Enter





5) Type a description for the field6) Press EnterContinue this until all necessary fields have been entered into the table.Note: The order that you enter the field names is the order the fields willappear in the table and on a form.

To View the Datasheet:Click the View button on the Ribbon

Setting a Primary KeyThe Primary Key is the unique identifier for each record in a table. Access willnot allow duplicate entries in a Primary Key field. By default, Access sets the firstfield in the table as the Primary Key field. An example of a Primary Key would beyour Social Security Number. This is something unique about you and shouldnot be duplicated.To Set a Primary Key:1) Switch to Design View2) Position your cursor in the field you wish to set as the Primary Key3) Click the Primary Key button on the Ribbon





To Switch Back to Datasheet View to Enter your Records:Click the View button on the Ribbon.

Entering Data in a TableOnce you have entered the fields and set the data types it is now time to enterthe records in a table.To Enter Data in a Table:1) Make sure you are in Datasheet View2) Enter the data into the table by pressing the tab key to move from one cellto another3) When you have completed the record (row), press Enter

When inputting data into the table, Access automatically saves the data after





each new record.

Input MasksAn Input Mask is used to pre-format a field to “look/act” a certain way when a user inputs data.Example: You could create an input mask for a Social Security Numberfield that automatically inserts the dash.The Input Mask data can either be stored in the table or simply displayed and not stored. To Create an Input Mask for a Field1) Open a table in Design View2) Click in a field for which you’d like to create an input mask3) In the Field Properties section at the bottom of the screen, click in theInput Mask line and notice the Build button that appears at the right endof the line (see below)

4) Click the Build button5) Select Input Mask6) Click Next67) Select a Placeholder character8) Click Next





9) Select Without the symbols in the mask10) Click Next11) Click Finish

Now, when entering data that has been formatted with an Input Mask, you do not have to type the format into the record.7The following is an example of a table with a field that has been formatted with an Input Mask on the Social Security Field.Notice, the only thing that the user has to enter is the digits, not the symbols.





Navigating RecordsUse the arrows at the bottom of the table to navigate among records.You are able to navigate from the first record, previous record, next record, lastrecord, and create a new record (as shown in the picture below).Notice that the total number of records in the table is shown at the right end ofthe navigation arrows.

Sorting Records in a TableBy sorting your records in a table, you are easily able to view/locate records inyour table.To Sort Records in a Table:1) Position your cursor in the field that you wish to sort by, by clicking on anyrecord in that field.

2) Click either the Sort Ascending or Sort Descending icon

Notice, the table above has been sorted by the Last Name field in ascendingorder.8

QueriesYou use Queries to view, change, and analyze data in different ways. You canalso use them as a source of records for forms and reports.To Create a Query:





1) Click the Create tab on the Ribbon2) Click Query Design icon

3) Double-click Create Query in Design View4) Select the table that you would like to base your Query on5) Click Add6) Close the Show Table windowThe table(s) will now be displayed in the upper part of the Query Design Screenby boxes containing the tables’ fields.7) Double click on the field names in the field list window which you wouldlike to include in the Query

Defining Criteria in the QueryIn order to control which records are displayed, you must define criteria in aQuery. The most common type of Query is the Select Records Query which willbe discussed below.To Define Criteria for your Query:1) Position your cursor in the criteria row in the field for which you wish to define the criteria for2) Enter the criteriaExample: To find all people it the table who live in Edison:9• Position your cursor in the criteria row of the City field• Type Edison• Click the Run Query buttonBelow is a picture of the results of the above query:





The result of a query is called a recordset. A recordset can be sorted, printed orfiltered in the same manner as a table.To Save the Query:1) Click the Save Icon2) Enter a name for the Query3) Click OK

Note: When saving a select Query, you are saving the question that you areasking, not the results that you see when you run the Query.





Creating a Form Using the Forms WizardA form is a database object that is used to enter or display data in a database.To Create a Form Using the Wizard:1) Navigate to the table you want to base the form on2) Click Create on the Ribbon3) Click FormsYou are able to navigate using the navigation arrows at the bottom of the form.Note: The form feeds the table. If you edit a record on the form, or create anew record, that data will be passed to the table it is associated with.

To Enter a Record on the Form:1) Click the View button on the Ribbon to switch from Layout View to FormView2) Enter the data for each field in the record, pressing the Enter key to moveto the next field3) Press Enter after you have entered data for the last fieldThis will send the record to the table.11

ReportsReports can be based on tables or queries and can be made with the ReportWizard.To Create a Report Using the Report Wizard:





1) Click the Create tab on the Ribbon2) Click the Report Wizard icon3) Select the table or query upon which the report will be based4) Select the fields that you want to include on the report by double clickingon them5) Click Next6) If you would like to add grouping to your report, select the field you wish togroup by double clicking on it (Example: City)7) Click Next8) Select a style for the report9) Click Next10) Type a title for the report11) Click Finish

To Print a Report1) Open the report by double clicking on the object in the Navigation Pane2) By default, the report opens in Print Preview.To Adjust the Orientation:Click the portrait or landscape icon on the Print Preview RibbonTo Adjust the Margins1) Click them Margins icon on the Print Preview Ribbon2) Select a margin sizeTo Print the Report1) Click the Print Icon on the Print Preview Ribbon2) Select the Printer3) Click OK

Summary of operators available in queries





Arithmetic Operators:

+ Adds two operands.e.g. [GCSEs]+[A levels]

- Subtracts two operands.e.g. [Value]-30

-(unary) Changes sign of operand.e.g. -6789

* Multiplies two operands.e.g.[Units]*[Unit Price]

/ Divides one operand by another.e.g. [Total] / 2

\ Divides one integer operand by another.e.g. [Units] \ 4

Mod Returns remainder of division by an integer.e.g. [Units] Mod 5

^ Raises an operand to a power (exponent).e.g. [Value] ^ [Exponent]

Comparison Operators:= Equal to.

e.g. =69> Greater than.

e.g. >69< Less than.

e.g. <69>= Greater than or equal to.

e.g. >=69<= Less than or equal to:

e.g. <=69<> Not equal to.

e.g. 69<>96

Logical Operators:

Return the logical values True, False or Null.And Logical and.Or Logical or.Not Logical not.

Other Operators:

Is Used with Null to determine if a value is Null or Not Null.e.g. Is Not Null

Like Determines whether a string value




NAMAKWA SS ICT DEPARTMENTAL NOTES 2017matches a “pattern”. Used in conjunction with wildcards (see Section 5.6).e.g. Like”*JOHN*

In Determines whether a string value is equal to any of a list of values.e.g. In(“Collingwood”, “Grey”, “Hatfield”)

Between Determines whether a numeric value lies within a range of values.e.g. Between 30 and 50

SENIOR FOUR TERM: TWOTOPIC 11: ELEMENTARY PROGRAMMING11.1. Introduction to programming11.2. Developing a simple program

TOPIC 12: TRENDS IN COMPUTING12.1. Computer integrity and securitySoftware integrityHardware integrityComputer intrusionComputer protection Use of surge protectors Use of UPS Use of strong passwords Use of antivirus Physical on site security i.e. computer locked in a room Use of fire walls Data encryption

Most common computer security threats and what you can do to protect yourself from them.





A threat, in the context of computer security, refers to anything that has the potential to cause serious harm to a computer system. THREAT 1: VIRUS A virus is a piece of software that can replicate itself and infect a computer without the permission or knowledge of the user. A virus can only spread when it is transmitted by a user over a network or the Internet, or through removable media such as CDs or memory sticks. Prevention, detection and removal: Antivirus software detects and eliminates known viruses.

THREAT #2: SPAM / SPIM / SPIT

SPAM is the sending of e-mail messages in bulk which are unnecessary. Email addresses are collected from chat rooms, websites, newsgroups and by Trojans which harvest users’ address books. SPIM is spam sent via instant messaging systems such as Yahoo! Messenger, MSN Messenger and ICQ. SPIT is Spam over Internet Telephony. These are unwanted, automatically-dialed, pre-recorded phone calls using Voice over Internet Protocol (VoIP). Prevention, detection and removal:ISPs attempt to choke the flood of spam by examining the information being sent and traffic patterns. User systems may use spam filters to screen out email messages with suspect titles or from suspect persons, as well email messages from blocked senders.

THREAT #3: SPOOFING, PHISHING AND PHARMING Spoofing is an attack in which a person or program masquerades (false show / pretence) as another. A common tactic is to spoof a URL or website (see phishing). Phishing is a common form of spoofing in which a phony web page is produced that looks just like a legitimate web page. The phony page is on a server under the control of the attacker. Criminals try to trick users into thinking that they are connected to a trusted site, and then harvest user names, passwords, credit card details and other sensitive information.





Phishing is typically carried out by email or instant messaging. The email message claims to be from a legitimate source but when the user clicks on the link provided, he or she lands on the fake web page. Pharming is an attack in which a hacker attempts to redirect a website's traffic to another, bogus website. Pharming can be conducted either by changing the hosts file on a victim’s computer or by exploitation of a vulnerability in DNS server software. DNS servers are computers responsible for resolving Internet names into their real IP addresses — the servers are the “signposts” of the Internet. Prevention, detection and removal:As spoofing, phishing, and to a lesser extent, pharming, rely on tricking users rather than advanced technology, the best way to handle these threats is through vigilance. Don’t open emails from unknown sources or click on links embedded in suspect messages.

Check the security guidelines of websites such as PayPal so that you can distinguish between legitimate and bogus emails.

THREAT #4: SPYWARE

Spyware is software that aids in gathering information about a person or organization without their knowledge and that may send such information to another entity without the consumer's consent.

Spyware is software that is secretly installed on a computer without the user’s consent. It monitors user activity or interferes with user control over a personal computer.

Prevention, detection and removal: Anti-spyware programs can combat spyware in two ways: 1 Real-time protection: these programs work just like anti-virus software. They scan all incoming network traffic for spyware software and block any threats that are detected.2 Detection and removal: users schedule daily, weekly, or monthly scans of their computer to detect and remove any spyware software that has been installed. These antispyware programs scan the contents of the Windows registry, operating system files, and programs installed on your computer. They then provide a list of threats found, allowing the user to choose what to delete and what to keep.





Some popular antispyware programs are Spybot - Search & Destroy, PC Tools’ Spyware Doctor, as well as commercial offerings from Symantec, McAfee, and Zone Alarm. THREAT #5: KEYSTROKE LOGGING (KEYLOGGING) A keylogger is a software program that is installed on a computer, often by a Trojan horse or virus. Keyloggers capture and record user keystrokes. The data captured is then transmitted to a remote computer. Prevention, detection and removal:For the time being, therefore, the best strategy is to use common sense and a combination of several methods:

Monitoring which programs are running: a user should constantly be aware of which programs are installed on his or her machine.

Antispyware: antispyware applications are able to detect many keyloggers and remove them.

Anti-keylogging software:keylogger detection software packages use “signatures” from a list of all known keyloggers to identify and remove them.

THREAT #6: ADWARE Adware is software which automatically plays, displays, or downloads advertisements to a computer. The adware runs either after a software program has been installed on a computer or while the application is being used. In some cases, adware is accepted by users in exchange for using software free-of-charge. Not all adware is innocuous, however. Some types of adware are also spyware and therefore a threat to privacy. Prevention, detection and removal:As adware is also often spyware or malware, programs have been developed to detect, quarantine, and remove both spyware and adware. Ad-Aware and Spybot - Search & Destroy are two commonly used programs. THREAT #7: BOTNET

A Botnet (also called a “zombie army”) is a collection of software robots, or bots, that run automated tasks over the Internet. The term “botnet” is generally used to refer to a distributed network of compromised computers (called “zombie computers”). These “zombies” typically run programs such as worms, Trojan horses, or backdoors.





Botnets are frequently used to launch Distributed Denial-of-Service (DDoS) attacks against websites. Newer bots can automatically scan their environment and propagate themselves using vulnerabilities and weak passwords. Prevention, detection and removal:Detection focuses on either the computer itself or the network. Both approaches use trial and error to try to identify bot behavior patterns. THREAT #8: WORM A computer worm is a self-replicating, malicious software program. Unlike a virus, it does not need to attach itself to an existing program or require user intervention to spread. It uses a network to send copies of itself to other computers on the network. Prevention, detection and removal: Since worms spread by exploiting vulnerabilities in operating systems, computers should be kept current with the latest security updates or “patches” from operating system vendors.

To prevent infection, users need to be wary of opening unexpected emails and should not run attached files or programs, or visit websites that are linked to such emails. Users should be constantly on guard against phishing.Antivirus and antispyware software, if kept up-to-date, are also helpful, as is the use of a firewall. THREAT #9: TROJAN HORSE A Trojan horse or Trojan is a piece of software which – like the Trojan Horse of Greek mythology – conceals a payload (often malicious) while appearing to perform a legitimate action. Trojan horses often install “backdoor programs” which allow hackers a secret way into a computer system.

Prevention, detection and removal: Normally, antivirus software is able to detect and remove Trojan horses automatically. They may also be deleted by clearing the temporary Internet files on a computer, or by finding the offending file and deleting it manually (in safe mode). THREAT #10: BLENDED THREAT





A blended threat is a threat that combines different malicious components, such as a worm, a Trojan horse and a virus. In this way, a blended threat uses multiple techniques to attack and propagate itself. Prevention, detection and removal:See respective entries for worm, Trojan horse and virus. THREAT #11: DENIAL-OF-SERVICE ATTACK (DOS ATTACK)As its name implies, a Denial-of-Service or DoS attack is an attempt to make a computer resource such as a website or web service unavailable to users. One of the most common methods of attack involves saturating the target (victim) machine with external communications requests. Prevention, detection and removal: Surviving an attack: The easiest way to survive an attack is to plan ahead. Set aside a separate emergency block of IP addresses for critical servers with a separate route. Firewalls: Firewalls follow simple rules to allow or deny protocols, ports or IP addresses. Some firewalls offer a built-in emergency mode. If the number of incoming packets per second exceeds a set value for more than the specified time, the firewall classifies it as a DoS attack and switches to emergency mode. In this mode, all inbound traffic is blocked except previously established and active connections, but outbound traffic is allowed.Some DoS attacks are too advanced for today's firewalls. If there is an attack on port 80 (web service), for example, firewalls cannot prevent the attack because they cannot distinguish between good traffic and DoS traffic. Another problem is that firewalls are too deep in the network hierarchy. Your router may be overwhelmed before the traffic even gets to your firewall.

Computer crime It refers to any crime that involves a computer and a network. The computer may have been used to carry out a crime, or it may be the target.

Computer crime is a form of crime where the Internet or computers are used as a medium to commit crime.

These include:Hacking,Denial of service attacks,





Unauthorized use of services Cyber vandalism,Hacking, Copyright infringement,Child pornography, Fraud, Money laundering, and counterfeiting, Cyber terrorism, Phishing,Pharming, Spoofing, Malware such as viruses, Identity theft and Cyber stalking

Hacking is the activity of breaking into a computer system to gain unauthorized access to information. The unauthorized revelation of passwords with intent to gain unauthorized access to private communication of a user is one of widely known computer crimes. Another highly dangerous computer crime is the hacking IP addresses in order to transact with a false identity, thus remaining anonymous without carringout the criminal activities.

Phishing is the act of attempting to acquire sensitive information like user name password and credit card details by distinguishing as a trustworthy source. Phishing is carried out through emails or by luring the users to enter personal information through websites. Criminals often use websites that have a look and fill of some popular webs which makes the users feel safe to enter their details there.

Computer viruses are computer programs that can replicate themselves and harm computer systems on a network without the knowledge of the system users. Viruses spread to other computers through sharing infected network files, through the network as a transport medium, by the means of removable devices like USB drives, DVDs, CDS. Computer viruses are all, forms of malicious codes written with an aim to harm a computer system and destroy information. Writing computer viruses is a criminal activity as virus infections can trash computer systems, thereby destroying great amounts of critical data.

Cyber stalking; the use of communication technology e.g. the internet to stalk a person online. The stalker sends threatening emails, spreads false information and accusation transmits to threats on the internet and damages data and equipment. Cyber stalkers often target the users by means of chartrooms, online forums and social networking websites to gather information and harass the users on the basis of the information gathered ,obscene emails, abusive phone calls and other such serious effects cyber stalking has made it a type of computer crime.




http://www.britannica.com/EBchecked/topic/140294/counterfeiting

http://www.britannica.com/EBchecked/topic/757090/money-laundering


Identity theft involves stealing money and obtaining other benefits by using another person’s identity. It is the act of pretending to be someone else by using someone else’s identity as ones’ own. Financial identity theft involves the use of false identity to obtain goods and services and a commercial identity theft is the using of someone else’s business name or credit card details for commercial purposes. Identity cloning is the use of another user’s information to pose as a false user. Illegal migration, terrorism and black mail are often made possible by means of identity theft.

Cyberextortion is a form of cyberterrorism in which a website, e-mail server, or computer system is subjected to repeated denial of service or other attacks by malicious hackers, who demand money in return for promising to stop the attacks.

Cyber terrorism in general, can be defined as an act of terrorism committed through the use of cyberspace or computer resources

Spam

Spam, or the unsolicited sending of bulk email for commercial purposes, is unlawful in some jurisdictions. While anti-spam laws are relatively new, limits on unsolicited electronic communications have existed for some time.[8]

Fraud

Computer fraud is any dishonest misrepresentation of fact intended to let another to do or refrain from doing something which causes loss.

Other forms of fraud may be facilitated using computer systems, including bank fraud, identity theft, extortion, and theft of classified information

Drug trafficking

Drug traffickers are increasingly taking advantage of the Internet to sell their illegal substances through encrypted e-mail and other Internet Technology. Some drug traffickers arrange deals at internet cafes, use courier Web sites to track illegal packages of pills, and swap recipes for amphetamines in restricted-access chat rooms.

Cyber Crime” describes criminal activities committed through the use of electronic communications media. orCyber crime can mean any criminal activity that takes place over the Internet. Examples include fraud,




http://en.wikipedia.org/wiki/Internet_cafe

http://en.wikipedia.org/wiki/Drug_trafficker

http://en.wikipedia.org/wiki/Drug_trafficker

http://en.wikipedia.org/wiki/E-mail

http://en.wikipedia.org/wiki/Classified_information

http://en.wikipedia.org/wiki/Extortion

http://en.wikipedia.org/wiki/Identity_theft

http://en.wikipedia.org/wiki/Bank_fraud

http://en.wikipedia.org/wiki/Bank_fraud

http://en.wikipedia.org/wiki/Computer_crime#cite_note-8

http://en.wikipedia.org/wiki/E-mail_spam_legislation_by_country

http://en.wikipedia.org/wiki/Email

http://en.wikipedia.org/wiki/E-mail_spam


How to control computer crime

Just like any sort of crime, common sense is your most valuable ally when dealing with cyber criminals,

Never open suspicious documents sent to email. Don't give out personal information to people you don't know. And be wary

when approached with a suspicious proposition.

Learn about cyber crime and talk to your family about how to identify scams. Never give out your personal information to anyone you do not know on the Web.

Use a firewall to protect your computer from hackers. Most security software comes with a firewall. Turn on the firewall that comes with your router as well.

Purchase and install anti-virus software such as McAfee or Norton Anti-Virus. AVG offers free anti-virus protection if you do not wish to purchase software.

Shop only at secure websites. Look for a Truste or VeriSign seal when checking out. Never give your credit card information to a website that looks suspicious or to someone you don't know.

Use strong passwords on your accounts that are difficult to guess. Include both letters and numerals in your passwords. Never use a word that is easy to guess -- like your wife's name.

Keep watch over your children and see how they use the Internet. Install parental control software to limit where they can surf.

12.2. Computer Ethics and integrity Computer ethics refers to a set of moral principles that regulate the

use of computers. Or the human values and moral conduct relating to right and wrong

behavior/decisions made when using computers. Computer integrity refers to steadfast loyalty to a strict moral or

principled set of laws regarding computer useSome of the Computer ethics and integrity that should be put in mind when using computers include:

8. Respect the privacy of others. Do not in any way examine or change files or passwords belonging to others. Do not violate the privacy of individuals or organizations.

9. Respect the integrity of the computing systems. Do not develop or use programs that invade, damage, or alter computing systems or software. Do not in any way harass other users.





10. Always identify the user accurately. Never use someone else's account. Do not use fraudulent means to avoid accounting for the use of computing services.

11. Respect copyrights and licenses. To copy a licensed computer program is illegal; it is indeed theft.

12. Respect the intellectual property of others. Individual programming assignments are expected to be done by individual students; do not take another's work or ideas to call your own.

13. Exhibit responsible, sensible use of computer hardware, software, and data.

SENIOR FOUR TERM: THREETOPIC 12: TRENDS IN COMPUTING (…..continued)12.3 Computers and societyImpact of computer on society Increased interactions or collaborations through emails, chat rooms, video

conferencing etc Increased inventions innovations such as wireless keyboards, wires

mouse Improved and sustained quality goods and services due to automated

production Improved corporate image ie firms use ICTs to create logos and headed

letters Many IT products for the disabled are being created i.e Baillie Keyboards Increased investment opportunities in commercial telephone centers,

internet cafes, chat room Creation of jobs that require high skills e.g. IT technicians, computer

operators, website designers, software developers

Negative implications of ict Widens the gap between the information rich and the information poor as

the rich produce products faster on the market than the poor Isolates older people since they do not find it easy to learn ad use ICT

gadgets very fast ICT avails people with lots of good and bad information from the internet Increased learning instability as people are compelled to learn new

technologies that come up every now and then





Reduced physical activities which in turn creates lots of health problem e.g.. eye strain, back problems etc

Erosion of individual privacy as more and more people’s private data is being stored in databases were others can access any time

Increased unemployment as less skilled people get retrenched and their jobs taken over by more effective ITs like Robots in factories

Addiction to computer usage (internet, music, Games etc) is on increase The initial maintenance and ICT facilities is very high e.g internet access

bills Virus threats as there is easy spread of virus through networking Increased computer crimes i.e. Hacking, phishing, software piracy etc

Impact of computers (needs to edited)SocialEase of access and availabilityLook at how modern ICT allows citizens today to communicate and participate in society. We use text messaging to vote on TV shows, enter competitions and have our opinions broadcast on national TV and radio. We use digital TV to order goods, vote on TV shows etc

We can have access to the Internet in our social lives as well with libraries having Internet access points and Internet cafes still being popular. Restaurants often have Internet access points and if you have stayed in a ‘big’ hotel lately you will find that the rooms have Internet access points for your laptop to plug into.

Information rich/information poor

There is some concern that the widespread use of computers is dividing society into two kinds of people – the ‘information rich’ and ‘information poor’. The information rich have easy access to computers and electronic communications. They get information and news from the Internet and buy the latest products through on-line shopping. They are able to follow computer-based learning and skills training courses at home, and look for jobs that are advertised solely on the Internet. They tend to find it easier to get well-paid jobs and will enjoy a more comfortable and secure life-style.

The information poor don’t have easy access to computers and don’t have the IT skills and confidence to take part in teleshopping, telebanking, Internet chat and news groups. As corporations like the BBC seek public opinion on





current matters increasingly via the Internet, the voices of the information poor may not be heard. The jobs on offer to them will be less skilled, paid less and much more insecure.

One effect of high levels of unemployment has been that families feel more secure with two wages coming into the family. This has meant that more and more mothers have careers. As a result, they may not have any children till they are thirty or older and even then they may only have one child because they do not want, or are afraid, to interrupt their careers.

More and more families enjoy television, computers and electronic games in their homes. Father may be watching television; mother may be teleshopping over the Internet while the children are in their bedrooms playing arcade games. Research has shown that families are spending less and less time together.

In addition, with the growth of teleworking, fewer people are meeting with colleagues to discuss business matters during the day. Computers are having an adverse effect on human communication skills and relations within the family and in society in general.

Educational qualifications and ICT. There have been qualifications in computing since the early 1960s, but these were solely in universities and colleges. Now there are many different courses offered at degree and NC level all related to ICT.

Economic

Another less obvious effect of computers and IT on the family is the change that banks have made to our lives. Before banks were computerized, most workers were paid weekly and in cash, and they did not need a bank account. With the introduction of computerization, banks started to persuade companies, government and local authorities to pay employees by cheque. As a result, very little cash is in circulation now compared with the 1950s and 60s because now people work with ‘plastic money.

Political

Environmental (green computing) the study and practice of designing, manufacturing, using, and disposing of computers, servers, and associated subsystems—such as monitors, printers, storage devices, networking and




http://en.wikipedia.org/wiki/E-waste


communications systems efficiently and effectively with minimal or no impact on the environment.

ICT’s such as internet are used to predict and track climate changes in agriculture, the incidence of forest fires, flood and drought patterns, the movement of invasive species just to name a few and develop appropriate management and adaptation strategies, and plot a course toward better environmental management.ICT’s applications can be used to impart information directly to farmers and the farming community. There are expert system designed to handle agricultural issues such as water utilization and management, pest control, harvest management and

12.4. Emerging technologiesWhat are computer immerging technologies?

Artificial intelligence Digital forensics is a branch of forensic science encompassing recovery and

investigation of material found in digital devices, often in relation to computer crime Artificial reality: artificial or simulated reality that is generated in 3D by a computer

and commonly known as VR, .artificial reality, virtual environments

12.5. System analysisI. Systems analysis is the dissection of a system into its component pieces to

study how those component pieces interact and work.II. System analyst is a person who researches problems, plan solutions,

recommends software’s and systems at least at the functional levels and co-ordinates development to meet business or other requirements. A system analyst does the following. 1. Identifies, understands, and plans for the organist ion planned systems, and ensure that new technical requirements are properly intergraded with existing processes and skill sets. 2. Plans a new system from the beginning to the end. 3. Interacts with the internal users and customers to learn and document requirements that shall be used to produce business requirements documents. 4. Write technical requirements from a critical phase. 5. Interact with designers to understand software limitations. 6. Help programmers during system development; provide use cases, flowcharts or even data base design. 7. Perform system setting. 8. Deploy the completed system. 9. Document requirements or contribute to user manuals.





10. Whenever a development process is conducted, the system analyst is responsible for designing components and providing that information to the developer.

III. Expert system is a computer system that imitates the decision making ability of a human expert. Expert systems are designed to solve complex problems by reasoning about knowledge, like an expert, and not by following the procedure of a developer as is the case in conversional programming. The first expert systems were created in the 1970’s.

IV. Artificial intelligence (AI) is technology and a branch of computer science that studies and develops intelligent machines and software.

70.State examples of data threats and give ways of curbing these threats.

12.6. Computer professions

.




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