COMPUTERIZED OFFICE MANAGEMENT Module 1 (COMPUTER FUNDAMENTALS) COMPUTER FUNDAMENTALS : INTRODUCTION : The term computer is derived from the Latin word compute which means to calculate. Computer is a fast and accurate electronic device that accept data, process data and produce output based on a set of stored programme of instruction. Charles Babbage is considered as the Father of the Computer because he introduces the idea of working on stored programme concept. (inventor of Differential Engine and Analytical Engine). The American Heritage Dictionary (1980) gives its first computer definition as a person who computes. The computer remained associated with human activity until about the middle of the 20th century when it became applied to a programmable electronic device that can store, retrieve, and process data. Today, the word computer refers to computing devices, whether or not they are electronic, programmable, or capable of storing and retrieving data Computer follows the principal word GIGO : Good Input Good Output Grater Instruction Grater Output Garbage In Garbage Out APPLICATION AND USAGE OF COMPUTERS : Computer has grown beyond its original purpose of computing. Today, it is used in all walks of human life. Its applications range from simple data entry to complex global electronic commerce, and online training to technology development. Ever since its invention, the power of computer has been growing rapidly. A large number of application software packages are now available that make computers highly productive, versatile and easy to use. Areas of usage include telecommunication, transportation, education and training, entertainment, publishing, military and police, engineering, production, healthcare and electronic Commerce. The use of computer is spreading to more virgin areas of human activities to make life more comfortable and leisurely. Computer can capture, store, retrieve and process data. The data may be numbers, characters, audio, video, images VHSE ക മ പ യ ട ടറ സ ഡ ഓഫ സ ഡ മ ന ജ മമന റ Computer Fundamentals Page 1
CHARACTERISTICS OF COMPUTER : 1. Speed Modern computers have incredible speed of processing. Computer speed is measured in units of millisecond (one thousandth of a second), microsecond (one millionth of a second), nanosecond (one billionth of a second), and picosecond (one trillionth of a second). Advanced computers, including recent microcomputers called super microcomputers, operate in nanoseconds and can carry out millions of instructions per second (MIPS). 2. Accuracy : Computer can ensure consistently very high degree of accuracy in computations, If input data and procedures are correct, the output will be consistently accurate. 3. Huge storage and fast retrieval : Computer has huge storage capability. Storage capacity differs depends on hardware. The main memory can be upgraded further by inserting RAM (Random Access Memory). Cache memory is faster access memory device and hence it improves processor performance. Secondary or auxiliary storage devices are used for permanent storage. Modern computers have enormous secondary storage capacit, Pen drives, Memory Cards, DVDs, CD-ROMs, Magnetic tapes etc. are other secondary storage devices. Huge storage and fast retrieval capability makes computer a very special tool for data processing and communications. 4. Versatility : Computers are basically designed to carry out only arithmetic operations, yet they are capable of performing almost any task that has a series of finite logical steps. Computers can be used for communications, process control, research, weather, forecasting, healthcare, online trading, education, training, defence applications and so on. 5. Free from fatigue : Computer is free from fatigue. It does not get tired of work and never loses concentration like human being. It can perform basic operations with the same degree of speed and accuracy for any extent of time continuously, with the same amount of efficiency as the first transaction. LIMITATIONS OF COMPUTER : 1. Computer cannot think on its own. 2. It does not have insight It cannot draw a conclusion without going through all intermediate steps. 3. It can do a task only if it can be expressed in a series of finite steps. 4. It cannot learn from experience. VHSE ക മ പ യ ട ടറ സ ഡ ഓഫ സ ഡ മ ന ജ മമന റ Computer Fundamentals Page 2
GENERATION OF COMPUTERS : First Generation (1940-1956) : The first generation computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. The UNIVAC and ENIAC computers are examples of first-generation computing devices. Second Generation (1956-1963) : In second generation Computers used Transistors for circutary and magnetic core technology for memory. It leads computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. High-level programming languages were also being developed at this time, such as early versions of COBOL (Common Business Oriented Language) and FORTRAN (Formula Translator). Third Generation (1964-1971) : The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. Fourth Generation (1971-Present) : The microprocessor (VLSI Very Large Scale Integrated Circuit) brought the fourth generation of computers, 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. 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 GUIs (Graphical User Interface). Fifth Generation (Present and Beyond) 1982 onwards : Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization. VHSE ക മ പ യ ട ടറ സ ഡ ഓഫ സ ഡ മ ന ജ മമന റ Computer Fundamentals Page 3
TYPES OF COMPUTERS : 1. MINI AND MAINFRAME : They have large storage capacity. They can use wide variety of softwares. They can be used for more mathematical calculatrions. They are installed in large commercial places and Government organizations. 2. MINI COMPUTERS : They have less memory and storage capacioty than mainfarame computes, limited range of softwares can be used. The end users can directly operate it. 3. MICROCOMPUTERS They are also known as Personal Computers. Its main components includes CPU, Monitor, Keyboard, Mouse, Sound System, Modem, Scanner and Printer. It can use wide range of softwares, it mainly used in offices and homes. 4. SUPERCOMPUTERS The supercomputers are the biggest and fastest machines today and they are used when billion or even trillions of calculations are required. These machines are applied in nuclear weapon development, thermal power stations, accurate weather forecasting and as host processors for local computer. They perform complex mathematical calculations, qualified and trained operators are required to operate them. Their speed ranges from 100 million-instruction-per-second to well over three billion. Because of their size. 5. LAPTOP COMPUTERS : They are battery or AC powered personal computers, it is portable than desktop computers. It is not easy to upgrade as easily as Desktop. 6. SERVER : Server serves information to other computers on a network. When we browse a page seb server computer delivers the page you requested. 7. TABLET : Tablet uses a touch sensitive screen for typing and navigation. It don t required a keyboard or mouse. It is more portable than laptop. Eg: ipad 8. MACS : It stands Macintosh developed by Apple Inc., it uses Mac OS X operating system. It is the first widely sold personal computer with GUI. 9. GAME CONSOLE : It is a specilized kind of computer that is used for playing video games. VHSE ക മ പ യ ട ടറ സ ഡ ഓഫ സ ഡ മ ന ജ മമന റ Computer Fundamentals Page 4
CLASSIFICATION OF COMPUTER BY THEIR BASIC OPERATING PRINCIPLE : Using this classification technique, computers can be divided into Analog, Digital and Hybrid systems. They are explained as follows: I ANALOG COMPUTERS : Analog computers were well known in the 1940s although they are now uncommon. In such machines, numbers to be used in some calculation were represented by physical quantities - such as electrical voltages. The computing units of analog computers respond immediately to the changes which they detect in the input variables. Analog computers excel in solving differential equations and are faster than digital computers. II DIGITAL COMPUTERS : Most computers today are digital. They represent information discretely and use a binary (twostep) system that represents each piece of information as a series of zeroes and ones. Digital computers manipulate most data more easily than analog computers. III HYBRID COMPUTERS : These are machines that can work as both analog and digital computers. VHSE ക മ പ യ ട ടറ സ ഡ ഓഫ സ ഡ മ ന ജ മമന റ Computer Fundamentals Page 5
BLOCK DIAGRAM OF COMPUTER : VHSE ക മ പ യ ട ടറ സ ഡ ഓഫ സ ഡ മ ന ജ മമന റ Computer Fundamentals Page 6