Information Technology

BRIEF HISTORY OF COMPUTERS

The history of the development of information technology can be divided into five:

eras: The computer as we know it today had its beginning in 19th century by an English mathematics professor named Charles Babbage. He designed the Analytical Engine and it was this design that the basic framework of the computers of today are based on.

By definition, a computer is any device capable of performing mathematical equations or calculations. Therefore, many simple devices such as an abacus (which dates back to at least 300 BCE) or a slide rule (first made in England in the 1630s) are the forerunners of today's modern computers.

The Calculating Clock: The first machine that worked like a computer was a gear-powered German device dubbed the Calculating Clock. It was first created by Wilhelm Schickard in 1623, and it operated by pulling or pushing rods set inside a glass case. A similar device known as a Pascaline became popular in the 1640s. These two devices were the forerunners of a steam-powered "difference engine" that was a pet project of Charles Babbage in the 1820s.

Computers can be classified into four generations. Each generation lasted for a certain period of time, and each gave us either a new and improved computer or an improvement to the existing computer.

First generation: 1937 – 1946 - In 1937 the first electronic digital computer was built by Dr. John V. Atanasoff and Clifford Berry. It was called the Atanasoff-Berry Computer (ABC). In 1943 an electronic computer name the Colossus was built for the military. Other developments continued until in 1946 the first general– purpose digital computer, the Electronic Numerical Integrator and Computer (ENIAC) was built. It is said that this computer weighed 30 tons, and had 18,000 vacuum tubes which was used for processing. When this computer was turned on for the first time lights dim in sections of Philadelphia. Computers of this generation could only perform single task, and they had no operating system.

Second generation: 1947 – 1962 - This generation of computers used transistors instead of vacuum tubes which were more reliable. In 1951 the first computer for commercial use was introduced to the public; the Universal Automatic Computer (UNIVAC 1). In 1953 the International Business Machine (IBM) 650 and 700 series computers made their mark in the computer world. During this generation of computers over 100 computer programming languages were developed, computers had memory and operating systems. Storage media such as tape and disk were in use also were printers for output.
Third generation: 1963 -  The invention of integrated circuit brought us the third generation of computers. With this invention computers became smaller, more powerful more reliable and they are able to run many different programs at the same time.
Fourth generation computers - present - After 1971 the fourth generation computers were built. The fourth generation computers were the extension of third generation technology. The fourth generation computers emerged with development of the VLSI (Very Large Scale Integration).With the help of VLSI technology microprocessor came into existence. The computers were designed by using microprocessor, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The fourth generation computers became more powerful, compact, reliable and affordable. As a result, they give rise to personal computer (PC) revolution.. In1980 Microsoft Disk Operating System (MS-Dos) was born and in 1981 IBM introduced the personal computer (PC) for home and office use. Three years later Apple gave us the Macintosh computer with its icon driven interface and the 90s gave us Windows operating system.

The Dawn of the Microprocessor: A microprocessor is a chip that basically contains an entire computer (or at least a 1940's era computer) using a integrated circuit. The first microprocessor was made by Intel in 1971. With the advent of this technology, the home computer become a possibility.

The First PC:The first personal computer for home use was the Altair 8800, which contained an Intel 8080 microprocessor. However, this computer had to be assembled by the person who bought it.

The Application of Information Technology  in Life

There are a lot of data that have to be managed in an educational  organisation. Among them student data, finance data, human  resources data, stock data and others. IT with the application of the  database system and Local Area Network can manage data  systematically and efficiently. For instance, with the help of this  system, an administrator will be able to know the studentÊs disciplinary status quickly. He only needs to enter the matriculation card number of the student into the computer connected to the network of student database. The same goes for other important information too for example finance, stock and human resources.  IT can be used to help in clerical work in schools. 

Teaching Aid 

The use of IT as a teaching aid can be divided into four that is: 

 • IT using tutorial mode 

 • IT using investigative mode 

 • IT using application mode 

 • IT using  communication mode 

 Computer based Teaching and Learning is another example of the use 

 of Information Technology in a variety of  modes as follows: 

 • The advantages of using the tutorial mode are: 

 – Teaching Aids are more interactive. This increases the 

 understanding and ability to grasp information. 

 – Students learn independently 

 – The application of the constructive and contextual learning 

 theory in teaching increases creativity  and motivates 

 students. 

 – It assists in creating an active learning environment.  

Advantages of using IT in investigative mode are: 

 – Students get to experience conducting difficult, expensive 

 and impossible experiments through virtual reality. 

 – Students can apply the constructive learning theory 

 – Students learn actively 

 – Students experience simulation learning 

 –

• Advantages of using IT in application mode are: 

 – Students can focus on the main activity 

 – Teaching  time is saved  

Advantages of using Information Techology in communication mode 

 are: 

 – It allows distance learning    

 – It allows communication between leaders and friends 

 – It applies peer group learning     

 – It applies collaborative learning theories   

 Internet in Education 

 The use of computers helps users to communicate effectively, fast and  cheaply.  Information sharing, meetings and discussions can be carried out through teleconferencing. The internet is also used for research and education. The Internet can be used with a variety of  media in its application. With this open and wide characteristic,  it is  not confined to any specific area, but is worldwide.  

The Internet helps educators in varying their learning and teaching aids with a variety of interesting media. The Internet facility allows the preparation of reference materials that are more extensive and varied. The Internet is viewed as a store of information that is accesible even from a distance. With Internet access, people around the world can communicate. It also brings education experts into the classrooms. 

 BASIC COMPUTER SYSTEM

The computer structure is divided into  three parts that is input, process and output.

An input device is a piece of hardware that is used to enter data into a computer.

There are many different kinds of input devices - so many in fact, that we have had to split this section into two separate mini websites. This one is about manual input devices. The second mini website is about automatic input devices.

Work your way through the pages by using the menu on the left. Once you have read them, have a go at the quiz and see how much you can remember.

1. Microphone

A microphone can be used to input sound.
The sound is detected by the microphone and an electrical signal is transmitted to the computer. Special hardware is used to convert this analogue data into digital data so it can be stored and manipulated.
In the last few years a number of voice recognition systems have been developed. These packages let the user dictate the text into a computer and then convert the speech to text.

Dictating like this can be much quicker than typing but the software isn't perfect and it can interpret a word incorrectly.

2. Keyboard

The keyboard is the most common and widely used input device.
It is made up of buttons called 'keys'. The keys are arranged into sections:

• alphabet keys
• Function or F keys (F1, F2, F3)
• Numeric keys (one set above the alphabet keys and a numeric keypad on the right)
• Arrow keys
• Command keys (insert, delete, home, end, page up/down)

Most keyboards are called 'QWERTY' keyboards. This name comes from the first six letters on the top row of the alphabet keys.
Using a keyboard for too long can lead to health problems such as repetitive strain injury (RSI). To try to overcome this, different styles of keyboard have been developed, for example, the ergonomic keyboard. They are supposed to put your hands into a much more natural position than a traditional keyboard.
 Advantages

• Most computers come with a keyboard supplied
• People are used to using keyboards to enter data, they need very little training
• A skilled typist can enter data very quickly
• Specialist keyboards are available e.g. ergonomic, gaming keyboards

Disadvantages

• It is easy to make mistakes when typing in data
• If you can't touch type, it can be time consuming to enter data
• Keyboards are not suitable for creating diagrams
• Disabled people often find keyboards difficult to use
• Excessive use can lead to R.S.I.

3. Mouse

Everyone is familiar with a computer mouse; along with the keyboard, it is one of the most common input devices you will use.

A mouse is also called a 'pointing device' because it enables you to control what happens on the screen by moving the mouse on your desk and pointing, clicking and selecting items on the screen.

A mouse usually has two buttons, a right and left one and also a central wheel which allows you to scroll up and down the page (some mice have three or four buttons). The left and right button have different functions. Left clicking usually lets you put your cursor at a certain point on the page or lets you choose a menu item. Right clicking brings you up a list of relevant menu items from which you can select a task.

Many of the older styles of mice used a ball which moved against two internal rollers to record the direction that the mouse was being moved in. Recent versions of mice use 'optical' or 'wireless' technology to track mouse movement.

Advantages

• Ideal for use with desktop computers
• Usually supplied as part of a new computer system
• Most computer users are familiar with them and require little training
• Works well in conjunction with a keyboard for data entry

Disadvantages

• They need a flat space close to the computer
• The rollers in mice that use balls can become clogged with grease and grime and lose their accuracy until cleaned.
• Overuse can lead to RSI

5. Joystick

Joysticks were originally used by pilots as part of an aeroplane's controls and the technology was developed to let computer gamers experience a more realistic game environment.
You can move joysticks in many directions and the joystick tells the computer which direction it has been moved into. They also have one or more buttons whose position when pushed can be read by the computer.
Joysticks can also be used for controlling machines such as cranes, trucks and powered wheelchairs.

Advantages

• They give a better gaming experience for racing or flying styles of computer games

Disadvantages

• Some people find joysticks more difficult to control than a traditional mouse.
• Joysticks are not particularly robust and can break easily if too much force is used on them.

6. Concept Keyboard

A concept keyboard is a flat board that contains a grid of buttons. Each button can be programmed to do whatever you want.
An overlay sheet with pictures or symbols is placed on the grid so that the user can tell what pressing on different areas will do.
Concept keyboards are used when fast input is needed and are ideally suited to selecting from a limited range of choices such as fast food restaurants. Checkout tills such as McDonalds use symbols to make ordering faster and easier. Primary schools often use them with young children. The overlay image could be a picture of a farmyard. Pressing on an animal would cause the computer to make the right animal noise.
Concept keyboards are particularly useful for people who would find using an ordinary keyboard difficult. It is also very handy in locations where an ordinary keyboard might be damaged e.g. by spillage or dust.

Advantages

• Much faster for making non-text selections such as menu choices on the till of a fast-food outlet.
• The keyboard is waterproof which can be useful where there is dirt or the risk of splashes

Disadvantages

• Poor for text or numeric input - although some keyboards do include a numeric keypad so the operator can enter the amount sold.
• Limited to the options shown on the keyboard.

7. Touch Screen

A touch screen is the only device which works as both an input and an output device. You view the options available to you on the screen (output) and you then use your finger to touch the option that you have chosen (input).
Touch screens work particularly well with a menu driven interface. For example, a cashpoint (ATM) at a bank would first of all ask which service you want. You touch the option 'withdraw cash' on the screen. You are then presented with another choice, 'how much cash do you want to withdraw?'. Once you have chosen how much, you then get other options such as 'do you want a receipt?'.
Touch screens are easy to use and are often found in public places such as cashpoints at banks, ticket collection terminals at theatres or airports, information centres at museums.
Touch screens are not commonly used to input large amounts of data because they are not very accurate and they would be tiring on the hands to use for long periods of time.
 Advantages

• Easy to use - intuitive, don't need much training
• No extra peripherals such as a mouse are needed
• Software can alter the screen while it is being used, making it more flexible than a concept keyboard which has a permanent overlay.

Disadvantages

• Not suitable for inputting large amounts of data
• Not very accurate - selecting detailed objects can be difficult with fingers
• Tiring to use for long periods
• More expensive than alternatives such as a mouse
• Not robust - can soon become faulty if misused.

8. Scanner

Scanners can be used to convert images or text on paper into a digital format that can be used by the computer.
A scanner works by shining a beam of light onto the surface of the object that you are scanning. This light is then reflected back onto a sensor that detects the colour of the light. This is then used to build up the digital image.
Items that are scanned are usually stored in an image format. However, special software - Optical Character Recognition - can be used to convert text on the paper into text which can be edited with a word processor. However, the text doesn't always get converted very well and you could end up with a lot of mistakes.
There are two types of scanner:

• Flatbed scanners
• Handheld scanners

The most popular type is the flatbed scanner. This is probably the one that you use at school. They can scan larger images and are more accurate than handheld scanners.
Handheld scanners are usually only a few inches wide and are held in the hand whilst they are rolled across the document to be scanned. The images produced are generally not as large or as high quality as those captured with a flatbed scanner.
Advantages

• Flatbed scanners are very accurate and can produce reasonably high quality images
• Any image which is digitised by the scanner can then be included on electronic documents
• Images once digitised can be enhanced with a graphics application

Disadvantages

• Images can take up a lot of memory space
• Images lose some quality in the scanning and digitising process
• The quality of the final image is dependent on the quality of the original image

9. Digital Camera

A digital camera records images electronically on a memory card rather than on film as did the older models of camera. The images can be downloaded from the memory card onto a computer and then printed, stored or manipulated with a photo editing application.
Most digital cameras let you view the image as soon as you have taken the picture; if you don't like what you see, it can be deleted.
The quality of the image is dependent on the resolution or the number of pixels. Most digital cameras range from 4 - 12 Megapixels (millions of pixels in the image). The more pixels, the better the quality and clarity of the image.
Many digital cameras are now capable of taking short video clips along with sound.

Advantages

• No film is needed, no developing costs to view the pictures
• Images can be viewed immediately and unwanted images can be deleted
• Images can be edited, enlarged or enhanced
• Images can be incorporated into documents or added to web sites
• Extra memory sticks can be purchased to store images

Disadvantages

• Digital cameras are generally more expensive than ordinary cameras which use film
• Images often have to be compressed to avoid using too much memory
• When the memory is full, the images must be downloaded to a computer or deleted before any more can be taken.

10. Graphics Tablet

Graphics tablets are often used by graphics designers and illustrators.
Using a graphics tablet, a designer can produce much more accurate drawings on the screen than they could with a mouse or other pointing device. Drawings created using a graphics tablet can be accurate to within hundredths of an inch.
a graphics tablet consists of a flat pad (the tablet) on which you draw with a special pen. As you draw on the pad, the image is created on the screen.

Advantages

• It is much more natural to draw diagrams with a pencil type implement (the stylus) rather than with a mouse
• A great level of accuracy can be achieved

Disadvantages

• Not really suitable for general selection work such as pointing and clicking on menu items
• Graphics tablets are much more expensive than a mouse

Automatic input devices

Sensors

Sensors are often used as part of a feedback cycle. They collect data continuously and are typically linked to a control program that specifies acceptable levels, eg the minimum and maximum temperature in a green house. The control program decides what to do next based on the data it's fed by the sensors.

Barcode reader

Barcodes are represented by black vertical bars and are read by a barcode reader. Barcodes are printed on nearly every product you buy, each product has a unique code. When read, information stored in the shop's database is recalled, such as the product name and price. This information later appears on your receipt. The scanning process also assists in stock management, reducing the stock by one each time a product is scanned/sold.

Magnetic strip (or stripe) reader

Magnetic stripes are built into many plastic cards such as debit or credit cards and personal identity cards. The magnetic strip on the back of the card can hold the personal details of the card owner and, with the necessary PIN, will allow access to secure information, eg bank account details. Data stored on the strip is scanned and input into a computer system by a magnetic stripe reader.

Magnetic Ink Character Reader (MICR)

Magnetic ink characters appear at the bottom of cheques. Banks use MICR to read the numbers from the bottom of cheques to obtain data such as account numbers and bank sort codes. A particular font is used that makes it easy for the machine to discriminate between characters. The ink is magnetised, this makes it immune to creases and dirty marks.

Optical Mark Reader (OMR)

An OMR reads marks made by pencil on a printed form into the computer. OMR systems are suited to reading pre-printed forms and check boxes such as National Lottery number selection sheets and multiple choice exam papers.

Split Keyboard

A "fixed-split keyboard" is a single board, with the keys separated into two or three groups, allowing the user to type at a different angle than the typical straight keyboard.
An "adjustable split keyboard" has the keyboard split into several independent pieces, so the angle between them can be easily changed.

[edit] Contoured Keyboard

The Kinesis Advantage contoured keyboard

A further development of the split concept are contoured keyboards like the Kinesis Advantage line, which place the keys into two depressions set approximately at shoulder width, with function keys set between the key groups for use with the thumbs. In this configuration, very little movement of arms and wrists is required.

[edit] Angled Split Keyboard

The angled split keyboard (sometimes referred to as a Klockenburg keyboard) is similar to a split keyboard, but the middle is tented up so that the index fingers are higher than the pinkie fingers while typing. Key Ovation makes the Goldtouch ergonomic keyboard which is an adjustable angled split keyboard.

[edit] Other Ergonomic Keyboards

Other ergonomic keyboards have fixed, vertically aligned keys, so the user types with their hands perpendicular to the ground, thumbs-up. Still others allow a range of rotation and elevations. A few ergonomic keyboards do not have the typical one key per letter, such as a keyer or a keyless ergonomic keyboard.^[2] Datahand eliminates the need for any wrist motion or finger extension.

Input devices allow us to enter raw data into a computer. The computer processes the data and then produces outputs that we can understand using an output device. Input devices can be manual or automatic.

The processing is mainly handled by the Central Processing Unit (CPU).

Manual input devices

The most common manual input devices are the keyboard and mouse. Other manual input devices include:

Concept keyboard

Each button on a concept keyboard relates to a particular item or function. Buttons can be labelled with text or a picture. Fast food restaurants often use concept keyboards because very little training is needed to operate them and they're efficient - a single button can order an entire meal.

Trackball

Used as an alternative to a mouse. To operate it the user rotates the ball which moves the pointer on screen. They are particularly easy to use for those with limited movement in their hands and are often used in Computer Aided Design (CAD) for their increased precision over a mouse.

Joystick

Joysticks used to be popular with gamers but have slowly been replaced by other types of game controller. In construction, joysticks are used to control machinery such as cranes.

Digital camera

A digital camera takes pictures and can usually record video too. The pictures it takes and the videos it records are stored in files. These files can be copied to a computer and later edited.

Microphone

Microphones are used to input sound. In computing they can be used with voice recognition software and a word processing application to enter text. Webcams commonly have microphones built-in too.

Touch screen

A touch sensitive visual display unit (VDU) or screen has a grid of light beams or fine wires criss-crossing the screen that are used to detect touch. Many mobile phones use touch screens and do away with the keypad entirely. They're often used on cash machines and in shopping centres too. Touch screens are robust, easy to operate and easy to reprogram.

Video digitiser

A video digitiser takes an image from a video camera or television and digitises it so it can be read by, and stored on, a computer. Video sequences captured using a video digitiser are often used in multimedia presentations.

Scanner

A scanner can be used to digitise images. They're similar to a photocopier but they make a digital copy instead of a physical copy. They can also be used with optical character recognition (OCR) software to scan in text that is then editable.

Graphics tablet

A graphics tablet consists of a flat pad (the tablet) on which the user draws with a special pen. As the user draws on the pad the image is created on the screen. Using a graphics tablet a designer can produce very accurate on-screen drawings as if they were drawing on paper.

Processing

Central Processing Unit

The CPU (Central Processing Unit) is the part of a computer system that is commonly referred to as the "brains" of a computer. The CPU is also known as the processor or microprocessor.

The CPU is responsible for executing a sequence of stored instructions called a program. This program will take inputs from an input device, process the input in some way and output the results to an output device.

CPUs aren’t only found in desktop or laptop computers, many electronic devices now rely on them for their operation. Mobile phones, DVD players and washing machines are examples of equipment that have a CPU.

Output devices

Common outputoutput: the term denoting either an exit or changes which exit a system and which activate/modify a process formats are printed paper, sound, video and on-screen documents. They let the computer communicate with the user. Examples of devices that take advantages of these formats are:

Monitor

The most common output device is the monitor or VDU.

Modern monitors, where the case isn’t more than a few centimetres deep, are usually Liquid Crystal Displays (LCD) or Thin Film Transistors (TFT) monitors.

Older monitors, where the case is likely to be around 30 cm deep, are Cathode Ray Tube (CRT) monitors.

Printers

·         Laser printers are quite expensive to buy and run but produce a high quality output and are quiet and fast.

·         Ink-jet printers offer black and white or colour printing with reduced levels of quality and speed. Colour ink jet printers are cheaper to buy than colour laser printers.

·         Dot matrix printers are not so common today. They are comparatively noisy and low quality but are cheap to run and are used when carbon copies or duplicates need to be made, such as for wage slips. Also, they are useful in dirty environments such as a garage because they are much sturdier than the other two types of printer.

Plotters

A plotter can be used to produce high quality, accurate, A3 size or bigger drawings. They are usually used for Computer Aided Design (CAD)Computer Aided Design (CAD) software: used extensively in the automotive industry, aerospace industry, and in architectural design to draw 2D and 3D designs and Computer Aided Manufacture (CAM) applicationsapplication: applications serve a specific purpose, eg Microsoft Word is used for word processing, such as printing out plans for houses or car parts.

Other output devices

Many other types of output device exist including:

·         speakers

·         projectors

·         buzzers

·         motors

·         switched outputs

·         lights

·         mechanical devices, eg a robot arm

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