Introduction to ICT - Lesson 1 PDF

Introduction to ICT – Lesson 1 INTRODUCTION TO INFORMATION AND COMMNICATION TECHNOLOGY / COMPUTER SYSTEMS OUTLINE - Concepts of ICT - Functions of ICT - History of Computers - Classification of Computers - Components of a comp...

Introduction to ICT – Lesson 1 INTRODUCTION TO INFORMATION AND COMMNICATION TECHNOLOGY / COMPUTER SYSTEMS OUTLINE - Concepts of ICT - Functions of ICT - History of Computers - Classification of Computers - Components of a computer system OBJECTIVES - Explain the concept of ICT - Explain the functions of ICT - Discuss the history of computers - Classify computers - Describe the components of a computer CONCEPT OF ICT ICT stands for Information and Communication Technology defined as a diverse set of technological tools and resources used to communicate, to create, disseminate, store and manage information. These technologies include computers, internet, broadcasting technologies i.e ( radio and television) and telephony. Information and Communication Technology it is an umbrella term that includes any communication device or application encompassing: computers, networks, hardware and software as well as various application associated with them A computer is an electronic device, operating under the control of instructions stored in its own memory that can accept data (input), manipulate the data according to specified rules (processes), produce results (output), and store the results for future use. A computer can also be defined as a machine, which accepts data from an input device performs arithmetical and logical operations based on predefined program and finally transmits the processed data to an output device. A computer peripheral is an auxiliary device that is connected to a computer but is not part of the core computer architecture. The core elements of a computer are the central processing unit, power supply, motherboard and the computer case that contains those three components. Peripherals are normally used to extend the functionality of a computer system. For example, consider a printer. Once the printer is connected to a computer, you can print out documents. Another way to look at peripheral devices is that they are dependent on the computer system. For example, most printers can't do much on their own, and they only become functional when connected to a computer system, There are three different types of peripherals: Input, used to interact with, or send data to the computer (mouse, keyboards, etc.) Output, which provides output to the user from the computer (monitors, printers, etc.) Storage, which stores data processed by the computer (hard drives, flash drives, etc.) 1|Page  Introduction to ICT – Lesson 1 Data is a collection of un-organized facts, which can include words, numbers. Images and sounds. Computers manipulate and process data to create information. Information is processed data that is organized, has meaning, and is useful. Examples are reports, newsletters, a receipt, a picture, an invoice, or a check. Data is processed and manipulated to create a check. Tasks of a Computer a) Input: - A computer accepts the information from the user. This is called input. b) Storage: - A computer stores data or information until it is ready for use. The date is stored in memory locations called memory. c) Processing: - A computer has a Central Processing Unit (CPU) which is responsible for processing all the data. d) Output: After processing data a computer conveys or returns the information to the user and this is called output. Data entered into a computer is called input. The processed results are called output. Thus, a computer processes input to create output. A computer also can hold data and information for future use in an area called storage. This cycle of input, process, output, and storage is called the Information Processing Cycle. FUNCTIONS OF ICT ICT has become an integral and accepted part of everyday life for many people. - ICT in education acts as a tool and medium for teaching and learning. - In business ICT such as Mobile technologies are offering new opportunities to the society e.g. in Agriculture, banking manufacturing etc - In support ICT is used to provide access to and dissemination of ICT resources - Economic growth through e-commerce, online and mobile transactions - In management ICT acts as a tool of management enabling organizations automate processes e.g. procurement, recruitment and thus achieving efficiency and effectiveness HISTORY OF COMPUTERS OR GENERATION OF COMPUTERS a) First Generation (1940-1956) Vacuum Tubes and magnetic Drums The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often very large, taking up entire rooms. Key characteristics of First Generation Computer i) They were very expensive to operate ii) They consumed a lot of electricity power, iii) They generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language, the lowest-level programming language i.e. machine language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts. The Universal Automatic Computer (UNIVAC) and Electronic Numerical Integrator and Computer (ENIAC) computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951. b) Second Generation (1956-1963) Transistors 2|Page  Introduction to ICT – Lesson 1 Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers have the following characteristics Key characteristics of second Generation Computer i) Smaller in size ii) Faster iii) Cheaper iv) More energy-efficient and more reliable than their first-generation predecessors Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output. Second-generation computers moved from Machine language to symbolic, or Assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology. c) Third Generation (1964-1971) Integrated Circuits The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were reduced and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. Key characteristics of Third Generation Computer i) The ICs are much smaller as compared to the physical electronic components hence the resulting computer was reduced in size as compared to the second-generation computers. ii) The small circuitry that resulted, improved the processing speed for pulses, e.g., data pulses can flow faster from one module to another as compared to the flow within the larger circuits, where they travel considerable distance. iii) They have higher main memory capacity, reliable than the second-generation computers. iv) These computers are of increased processing power as compared to the second-generation computers, i.e., these computers have the capability of holding more than one sets of instructions (programs) and operate on them apparently, what is described as multiprogramming. v) These computers can support more than one users at the same time, as connected through communication links from the work stations, which can be situated over a long distance or within the same locality of the host computer, that is to say in short that these computers have got the capability to support communication facilities, i.e., remote communication facilities. Examples of such computers are ICL 1900 Series, IBM 360. d) Fourth Generation (1971-1984) Integrated Circuits or Microprocessors The fourth generation computers were a modification of the third generation computer's technology. They use complex circuitry, an enhancement of the IC technology of the third generation computers. The design of this generation computer is based on Large Scale Integration (LSI) of circuitry and Very Large Scale Integration (VLSI) of circuitry. 3|Page  Introduction to ICT – Lesson 1 The microprocessor resulted from thousands of integrated circuits built onto a single silicon chip. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of Graphical user Interfaces (GUIs), the mouse and handheld devices. This generation marked the origin of mini computers in use today. e) Fifth Generation (1984-1990) VLSI technology The design of these computers was based on the VLSI technology, the micro chip technology that gave rise to the smaller computers, known as the micro computers in use today. Examples of microcomputers are IBM PC's (IBM personal computers), BBC micro etc. The micro computers are usually described as PCs or stand alone or desk top computers because they were designed primarily to serve single person at a time, though the trend is to have micro computers that can support more than one person at a time. The fifth generation is still a state of the art of technology that relies on predictions and further technological refinements. For example, the audio technology is still under technological refinement. f) Sixth Generation (1990 and beyond) Most of the developments in computer systems since 1990 have not been fundamental changes but have been gradual improvements over established systems. This generation brought about gains in parallel computing in both the hardware and in improved understanding of how to develop algorithms to exploit parallel architectures. Workstation technology continued to improve such as n-computing, with processor designs now using a combination of RISC, pipelining, and parallel processing. Wide area networks, network bandwidth and speed of operation and networking capabilities have kept developing tremendously. Personal computers (PCs) now operate with Gigabit per second processors, multi-Gigabyte disks, hundreds of Mbytes of RAM, colour printers, high-resolution graphic monitors, stereo sound cards and graphical user interfaces. Thousands of software (operating systems and application software) are existing today and Microsoft Inc. has been a major contributor. Finally, this generation has brought about micro controller technology. Micro controllers are ’embedded’ inside some other devices (often consumer products such as washing machines, cooling systems etc) so that they can control the features or actions of the product. They work as small computers inside devices and now serve as essential components in most machines. Research shows that the trend in the computer's technological revolution is that there is: i) Continual decrease in computer size; ii) Improved speed and power of processing; iii) Decrease in computers and its related facilities cost; iv) Number of components per circuit (IC) greatly increased, over 500,000 physical elements, e.g., transistors, capacitors, diodes, etc per chip (IC). CLASSIFICATION OF COMPUTERS Computers differ based on their data processing abilities. They are classified according to purpose, data handling and functionality. a) Classification according to Purpose According to purpose, computers are either: 4|Page  Introduction to ICT – Lesson 1 - General purpose computers are designed to perform a range of tasks. They have the ability to store numerous programs, but lack in speed and efficiency. - Specific purpose computers are designed to handle a specific problem or to perform a specific task. A set of instructions is built into the machine. b) Classification according to Data handling According to data handling and functionality, computers are analog, digital or hybrid. - Analog computers use continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. They work on the principle of measuring, in which the measurements obtained are translated into data. Modern analog computers usually employ electrical parameters, such as voltages, resistances or currents, to represent the quantities being manipulated. Such computers do not deal directly with the numbers. They measure continuous physical magnitudes. - Digital computers are those that perform calculations and logical operations with quantities represented as digits, usually in the binary number system that operate with information, numerical or otherwise, represented in a digital form. Such computers process data into a digital value (in 0s and 1s). They give the results with more accuracy and at a faster rate. - Hybrid computers incorporate the measuring feature of an analog computer and counting feature of a digital computer. For computational purposes, these computers use analog components and for storage, digital memories are used. They offer a combination of computers those are capable of inputting and outputting in both digital and analog signals. A hybrid computer system setup offers a cost effective method of performing complex simulations. c) Classification according to Size i) Super Computer They are the fastest and most powerful type of computers. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. For example, weather forecasting. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration. ii) Mainframe Computer They are very large and expensive computers capable of supporting hundreds, or even thousands, of users simultaneously. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe. The main difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programs as fast as possible, whereas a mainframe uses its power to execute many programs concurrently. iii) Mini Computer It is a midsized computer. In size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations. But in general, a minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously. iv) Micro Computer or Personal Computer A microcomputer is a computer with a microprocessor as its CPU. It is physically smaller than a mainframe and a minicomputer. Many microcomputers are equipped with a keyboard and screen for input and output. They were very common during the 1970s and 1980s. 5|Page  Introduction to ICT – Lesson 1 v) Desktop Computer: a personal or micro-mini computer sufficient to fit on a desk. Desktops and tower PCs are not portable because they rely on an outside power source and are not designed for frequent movement. Typically the desktop PC’s monitor is positioned on top of system unit component. The processing component of the tower PC is designed to sit upright. The tower may be placed in any convenient location like a nearby shelf or on the desk beside the monitor. vi) Workstations A terminal or desktop computer in a network. In this context, workstation is just a generic term for a user's machine (client machine) in contrast to a "server" or "mainframe." vii) Laptop Computer: a portable computer complete with an integrated screen and keyboard. It is generally smaller in size than a desktop computer and larger than a notebook computer. viii) Palmtop Computer/ Smart phones /Digital Diary /Notebook /PDAs: a hand-sized computer. A Smartphone is a cellular phone that performs many of the functions of a computer, typically having a touch screen interface, internet access and an operating system capable of downloading and running applications. Palmtops have no keyboard but the screen serves both as an input and output device. COMPONENTS OF A COMPUTER A computer system consists of both hardware and software. The hardware components of a computer system are the tangible electronic and mechanical parts while the software components of a computer system are the data, software and the computer programs. Hardware Components Hardware components include:- STORAGE DEVICES Processor Storage devices Input devices Output devices INPUT PROCESSOR OUTPUT Software Components Software refers to a set of instructions or programs that control computer hardware and all the other peripherals. The purpose of software is to cause the computer to provide the user with the data processing facilities required. Software is categorized into two:- a) Application Software These are programs that are designed to perform specific tasks by users and are installed for a particular Application and they are categorized as follows: - i) Word Processing e.g. Microsoft word, Word perfect ii) Spreadsheets e.g. Ms Excel, Lotus iii) Graphic Applications e.g. Corel Draw, AutoCAD iv) Accounting Packages e.g. Sage, Quick books v) Desktop Publishing e.g. Microsoft Publisher, PageMaker vi) Database software e.g. Microsoft Access, Microsoft Sql etc vii) 6|Page  Introduction to ICT – Lesson 1 b) System Software These are programs that control the operations of the computer and its devices also assist in the running of application software. Types of system software include Operating systems, Utility programs and Translators System software consists of the programs that control. Functions of System Software - Starting up the computer. - Opening, executing, and running applications. - Storing, retrieving, and copying files. - Formatting disks. - Reducing file sizes. - Backing up the contents of a hard disk. - System software serves as the interface between you (the user), your application software and your computer’s hardware. REVIEW QUESTIONS 1. Distinguish between a computer and a Peripheral 2. Discuss the history of computers 3. Outline the classification of computers based on function, data handling and size 4. Using relevant examples outline the components of a computer system 5. Discuss the different types of computers 7|Page