Computer Fundamentals Computers have made great inroads in our everyday life and thinking. They are put to use for all sorts of application ranging from complex calculations in the field or frontline research, engineering simulations down to teaching, printing books and recreational games. The ease with which computers can process data, store and retrieve it painlessly has made them inevitable in office and business environment. Therefore, it is essential for every person to know computer, its strengths, its weakness and its internal structure. What is computer? A computer is an electronic device that can perform a variety of operations in accordance with a set of instructions called program. Functional components of computer system 1 / 8
1. Input unit 2. Output unit 3. CPU 4. Memory 5. Storage devices Input Unit Input unit is a unit through which user communicates with the computer. It acts as a translator between the user and the computer. it converts the given data into computer acceptable form. Functions of input devices are: 1. Accepts data and instructions from user. 2. Coverts accepted data into machine language. 3. Gives converted data and instructions to CPU for processing. 2 / 8
Examples of input devices are Keyboard, Mouse, Light pen, Joystick, Magnetic ball, MICR, OCR, etc. Output Unit Output unit is a unit through which computer communicates with the user. It acts as a translator between the computer and the user. It converts the processed data from machine language to some natural language like English, which user can understand easily. Functions of output devices are: 1. Accepts processed data from CPU. 2. Converts results from machine language to some natural language. 3. Displays results to user. Examples of output devices are Printer, Plotter, VDU, Magnetic disk drive, Speaker, Floppy disk drive, etc. CPU (Central processing unit) All the processing work of computer is performed by CPU. It controls all the parts of computer system and is termed as BRAIN of the computer. It has three components: 1. ALU (Arithmetic and Logic Unit) 3 / 8
2. CU (Control Unit) ALU: This unit performs all arithmetic and logic operations. CU: This unit controls and guides the interpretation, flow and manipulation of all data and information. Another important function of CU is the program execution. Memory It is also termed as primary memory or central memory or internal memory. It is only the memory which is in direct contact with CPU. It is quite costly and its storage capacity is small. It is used to store data and program that is being executed currently. It is of two types- RAM and ROM. Functions of main memory are: 1. It temporarily holds the data received from input devices. 2. It holds the data being processed and the intermediate results. 3. It holds the final results and releases them to output devices when required. 4. It holds the system software and the application software in use. 4 / 8
Storage devices Since computers main memory is temporary, secondary memory space is needed to store data and information permanently for later use. Some common secondary storage media are the floppy diskette, the hard disk and the CD-RWs, etc. The secondary memory devices are also known as STORAGE DEVICES. Hardware Hardware represents the physical and tangible components of the computer. Input devices, CPU, floppy disk, harddisk, etc are the example of computer hardware. Software It represents the set of programs that govern the operation of a computer system and make the hardware run. Strengths of computer 1. Its speed is much faster as compared to human beings. 2. It has high storage capacity. 3. It can perform all the calculations and comparisons accurately. 4. Computers are more reliable than human beings. 5 / 8
5. Computers are versatile to repetitive jobs. Limitations of computer 1. Computers cannot decide on their own which a great asset of human being is. 2. They have zero IQ. EVOLUTION OF COMPUTERS The word generation of computer refers to different hardware technologies used in computers. It provides an idea about the growth in the computer industry. Till today there are five generations of computers. 6 / 8
Major features of first generation of computers are 1. Main component: Vacuum tubes 2. Size: Equivalent to a room 3. Speed: Few hundred instructions per second 4. Main memory: Magnetic drum 5. Secondary storage: magnetic drum and magnetic tape 6. Language: Machine and assembly language 7. Reliability: Failure of circuits in hour 8. Processing: Sequential Processing 9. Example: EDVAC, UNIVAC, Mark-1, etc. 7 / 8
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