ICT 3rd Semester Unit1

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<ol><li> 1. Unit 01: Introduction to Computer Computer Literacy 1 What is System? A system is a set of related components that interact with each other to perform some specific tasks. A set of detailed methods, procedures and routines created to carry out a specific activity, perform a duty, or solve a problem. An organized, purposeful structure that consists of interrelated and interdependent elements, components, entities, factors, members, parts etc. These elements continually influence one another (directly or indirectly) to maintain their activity and the existence of the system, in order to achieve the goal of the system. Characteristics of System: Structure Behavior Inter Connectivity Subsystems: A major part of a system which itself has the characteristics of a system, usually consisting of several components. Set of elements, which is a system itself, and a component of a larger system. Computer System: A complete, working computer along with software and peripheral devices that are necessary to make the computer function is called Computer system. Every computer system requires an operating system to operate. What is Computer? An electronic machine that can accept data (input), manipulate the data according to specified rules (process), produce results (output), and stores the results for future use. Computer in Latin means "to consider" or 'to compute'. Some experts have coined a word for it 'INFORMATIC', the science of information processing i.e. methods of recording, manipulation and retrieving information. So it is a calculating device with some special characteristics and abilities like perform complex and repetitive calculations rapidly and accurately, make decisions and automatically correct or modify by providing signals, certain parameters of a system under control, communicate with users through terminals etc. A computer is a programmable machine. The two principal characteristics of a computer are: it responds to a specific set of instructions in a well defined manner and it can execute a prerecorded list of instructions (a program). A computer is a general purpose device that can be programmed to carry out a fixed set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem. Usually, a computer consists of at least one processing element, typically a central processing unit (CPU) and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved. Data, Information and Knowledge: Data: Collection of raw facts and figures. Information: Processed form of data which is meaningful. Knowledge: Appropriate collection of information. Combination of data, information and experience. Information Processing Cycle: Series of input, processes, output and storage. A computer often holds data, instructions and information for future use. </li><li> 2. Unit 01: Introduction to Computer Computer Literacy 2 The Components of a Computer: Input devices Output devices System unit Storage devices Communications devices Importance of Computer: As we hurtle towards the 21st century, we must accept the certainty of a computer revolution in the near future. It is an undividable part of development, as demonstrated by other countries. Computers are no longer luxury or the sole property of the advanced countries. Their appropriate uses can help us solve the unique problems of a developing country and bring about the desired changes in increasing literacy, optimizing resources, increasing efficiency, productivity and quality. Already computers have become such an important part of our lives, in airports, banks, railway stations and every well equipped modern office. As computer continues to reproduce in ever increasing numbers across large segments of Government, business and industry, the common man is beginning to believe hesitantly that computers can actually deliver a good part of the promise that they had offered. Society is gradually accepting the fact that computers will indeed change the manner, in which the things are done. Computers can significantly save valuable man hours by helping people through communication to make reservation of tickets, operate their bank accounts, to pay for electricity water and telephone bills, insurance premium and also do routine shopping. Trains can be operated automatically by computers and traffic signals are computer coordinate to produce best traffic patterns, increase reliability and safety and generally provide for more efficient services. In areas of agriculture and irrigation, computers are making possible better matching of soil characteristics and crop. This coupled with better use of resources like water, fertilizers and sunlight and more precise prediction of monsoons can help in increasing crop yields manifold. Computer in health is bringing new hope for the sick. In areas of health and medicine, expert systems and data bases on blood groups availability, eye banks medical history of patients etc, can bring about a marked improvement in our health services. Expert system can help in more accurate diagnosis of ailments 'Hospital Information Systems' can help improve the efficiency of our hospitals reduce mortality and death rates and in general provide better and speedier health care to our people. While this realization is gaining firmer ground in areas like the utility services, railways, airlines, agriculture, health etc., as well as organization control, there is area where the role of computers as the prime agents of change has still not been recognized. That is the area of education. The number of illiterates at present is higher than that at independence. To tackle a problem of such huge proportions, it is essential that a modern aids offered by Information Technology is made use of to spread education to the rural areas where most of the illiteracy is concentrated. Computer based lessons developed in various subjects by experts in that area could be used to educate the masses. The computer is a rapidly evolving tool that can now deal quite effectively with all fine forms of information that man deals with for better education are data, text, image, graphics and voice. One thought can take place in our minds for a moment that 'the computer will replace the teacher that would be a suicidal thought. But we should fully accept the reality that the computer will fundamentally change the manner in which teaching-learning </li><li> 3. Unit 01: Introduction to Computer Computer Literacy 3 processes take place. The role of the teacher will undergo a fundamental change. From being a simple "information dumping machine", the teacher will once again rise to the height of being a mentor, philosopher and guide developing, instilling values, ideas, creating challenges and nurturing feelings, sentiments and empathy in young minds. In the wider prospective, these are what are required for building a strong nation, intellectually, spiritually and economically. In the most important area of government administration, to enable administration take the right decision at the right time, accurate, relevant and up-to-date information should be made available to them. Modern computerized communication network can significantly help bureaucracy cut its red tape. Therefore, computers are equal with development. With appropriate computer usage and quality of life applications, Pakistan will be able to effectively tackle its unique problems. The entire society will undergo a transformation and what would emerge is a society that is more intellectually aware and which values its time, intellect and dignity. A society armed with computer expertise can meet with confidence the exciting new Pakistan of tomorrow. Advantages: It helps you automate various tasks that you cannot do manually. It helps you organize and store your bulky data and information in a better way. It has much more computing and calculating power than an ordinary human. It may help your work to be a lot easier. It may be the storage of your important data and files. It may be your hand book. It may help you solve problems faster than an ordinary human being can do. It has speed, storage, reliability, consistency and communications. It helps you to find useful information using the Internet. It helps in businesses, factories, offices, schools and homes. Disadvantage: It destroys your social life and interactions with humans if you do not maintain the balance. It may effect to the destruction of your eye sight due to radiation. It may damage your studies and life. Too much time in front of monitor may adverse effect your eye sight and can also make you fat. The way it distracts and can deviate our thoughts and activities towards unproductive activities. It could cause violation of privacy, impact on labor force, health risks, impact on environment, distraction from work, and antisocial influences. Generations of Computer: 1. First Generation Vacuum Tubes: (1942-1955) 2. Second Generation TRANSISTORS: (1955-1964) 3. Third Generation Integrated Circuits: (1964-1975) 4. Fourth Generation Microprocessors: (1975- PRESENT) 5. Fifth Generation Artificial Intelligence: (Present and Beyond) 1. First Generation Computers (Vacuum Tubes) 1942-1955: The first generation of computers, characterized by vacuum tubes used in the duration of 1942-1955. Examples: ENIVAC (Electronic Numerical Integrator and Calculator) First Electronic Computer UNIVAC (Universal Automatic Computer) First Digital </li><li> 4. Unit 01: Introduction to Computer Computer Literacy 4 Computer used in business and industries. Vacuum Tubes electronic tubes about the size of light bulbs. Advantages: Vacuum tubes were the only components available during those days. Vacuum tube technology made possible to make electronic digital computers. These Computers could calculate data in milliseconds. Disadvantages: Very large in size. Consumed large amount of energy. Heated very soon due to thousand of vacuum tubes. Not very reliable. Air conditioning was required. Non-portable. Costly commercial production. Very slow speed. Used machine language only Used punch cards for input Not versatile and very faulty. 2. Second Generation Computers (Transistors) 1955-1964 Used Transistors. Transistors are developed in Bell Laboratories in 1947. The size of computer decreases by replacing vacuum tubes by Transistors. Examples: IBM 7097 series, IBM 1400 Series Transistor: A transistor is a semiconductor device used to amplify and switch electronic signals and power. Advantages: Smaller in size as compared to first generation computers. More reliable. Used less energy and were not heated. Better portability. Better speed and could calculate data in microseconds. Accuracy improved. Disadvantages: Air conditioning was required. Constant maintenance required. Only used for specific purpose. Costly and not versatile. Punch cards were used for input. 3. Third Generation Computers (Integrated Circuits) 1964-1975 Used Integrated Circuits. First IC was invented and used in 1961. The size of an IC is about square inch. A single IC contains thousands of transistors. Examples: IBM 370, IBM System/360 Advantages: Smaller in size as compare to previous. More reliable. Use less energy. Produce less heat as compare to previous. Better speed could calculate data in nanoseconds. Versatile to an extent. </li><li> 5. Unit 01: Introduction to Computer Computer Literacy 5 Used fan for heat discharge. Low maintenance cost because hardware failure is rare. Totally General purpose. Good Storage, Less expansive, better accuracy. Key board and mouse for input. Disadvantages: Air Conditioning was required. High sophisticated technology required for the manufacturing of IC chips. 4. Fourth Generation Computers (Microprocessors) 1975- PRESENT Starts with the invention of Microprocessors. Microprocessor contains thousands of ICs. Ted Hof creates first Microprocessor for Intel in 1971. Examples: Apple Macintosh &amp; IBM PC Advantages: More powerful and reliable then previous. Very small in size Less power consumption. Less heat generation. Used fan for heat discharge. No air condition is required. Totally General purpose. Less need of repairing. Cheapest among all the generations. Best speed to read instructions (One million per second). Disadvantages: The latest technology is required for manufacturing microprocessors. 5. Fifth Generation Computers (Artificial Intelligence) Present and Beyond Based on the technique of Artificial Intelligence (AI). Computers can understand spoken words. Scientists are working to increase the speed of computers. The advancement in modern technologies will revolutionize the computer in future. </li><li> 6. Unit 01: Introduction to Computer Computer Literacy 6 Types of Computer: Computer types can be divided into 3 categories according to electronic nature. 1. Analog Computer 2. Digital Computer 3. Hybrid Computer 1. Analogue Computer: Analogue types of Computer uses analogue signals that are represented by a continuous set of varying voltages and are used in scientific research centers. 2. Digital Computer: A computer that stores data in terms of digits (numbers) and proceeds in discrete steps from one state to the next. The states of a digital computer typically involves binary digits which may take the form of the presence or absence of magnetic markers in a storage medium. In digital computers, even letters, words and whole texts are represented digitally. 0,1 False true Low high 3. Hybrid Computers: Designed to display the features and characteristics of both analog and the digital computers. When the hybrid computers are used in the form of digital computers then they are deigned to act as the controller for the operations carried out in the system. When analog is taken into account then in that case the computer acts as a solution provider for different problems that exit. By depicting both the feature, it is found to be a beneficial computer. Classification of Computer: There are two types of classes: 1. Classes by Size 2. Classes by Functions 1. Classes by Size: 1.1 Microcomputers (Personal Computers) 1.2 Minicomputers (Midrange Computers) 1.3 Mainframe Computers 1.4 Supercomputer 1.1 Microcomputers (Personal Computers): Microcomputers are the most common type of computers used by people today, whether in a workplace, at school or on the desk at home. E.g. 1.1.1 Desktop Computers 1.1.2 Game Consoles Laptops 1.1.3 Notebook Computers 1.1.4 Palmtop Computers 1.1.5 Tablet PC 1.1.6 Programmable Calculator 1.1.1 Desktop Computers: A desktop computer is a personal computer (PC) in a form intended for regular...</li></ol>