Basic concepts in_computer_hardware_and_software

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  • 1. COMPUTER BASIC CONCEPTS IN COMPUTER HARDWARE AND SOFTWARE COMPUTERTHE NEED FOR COMPUTER LITERACYInformation is power and Computers are amplifiers of informationWhen a pregnant woman collapsed into hepatic coma, a surgeon contacted amedical library. He needed immediateinformation on blood transfusions from the blood banks. Using a computerterminal and a retrieval program, the librarian searched more than half amillion documents in just a few minutes. Necessary information was given tothe surgeon and the patient recovered fully.Most information retrieval do not involve life-or-death decisions, but quickercomputer assisted retrieval saves time and aggravation for many people.Information is a powerful commodity and is the driving force in our economytoday. Since, the amount of available information doubles after every twoyears or so, managing it becomes vital. The computer in fact, helps us tomanage information.Most of us, if not all of us are affected by the computer even if we are notactually using it. In the years to come, understanding the computer and its

2. uses and being able to use it will become as necessary as being able to use apen.Before understanding the various parts that constitute the computer and theworking of the computer, let us list some of the benefits, applications andlimitations of the computer.Benefits of ComputersThe three main benefits of using computers are :3Speed3Accuracy3Capacity to take large amount of work.Computer work at a very high speed and are much faster than humans. Thehuman equivalent of an average computer would be morethan one millionmathematicians working 24 hours a day.In addition to being fast, computers are very accurate. If the input and theinstructions are accurate the output will also be accurate.Unlike humans, computers do not get bored or tired. The monotony ofrepetitive work for long hours do not affect the computers.Applications of ComputersComputers are used in various fields ranging from making cartoon films tospace research.Some applications of computers are:3Railway reservation3Banking and Accounts3Weather Forecast3Space Research3Medical Diagnosis 3. 3Chemical AnalysisLimitations of ComputersThe Computer is one of the most powerful tools ever developed. Yet, we readarticles about instances, when a man received a telephone bill of Rs.10000,when he did not even have a telephone. Such failures sound amusing, butthey happen because of human errors.Computers have to be expressively told what to do. They cannot performanything that is not defined.TYPES OF COMPUTERSComputers are categorized on the basis of size, sot and performance.Generally, the larger the system, the greater is its processing speed, storagecapacity, cost and ability to handle large number of devices. The varioustypes of computers are:3Microcomputer3Personal computers3Minicomputers3Mainframes3Super computersMicrocomputers Systems on the lower end of the size of the size scale aremicrocomputers. They may be tiny special purpose devices dedicated tocarrying out a single task such as one inside a camera.Personal ComputersThe most popular form of computer in use today is the Personal Computergenerally known as the PC. The PC can be used for various applications. Itcan be defined as a single user oriented and general purpose microcomputer. 4. It can perform a diverse range of functions, from keeping track of householdaccounts to keeping records of the stores of a large manufacturing company.Lap Top ComputerLately, the Palmtops and Laptops have become very popular with their powerand portability.Mini ComputersMini computers are small, general-purpose computers. They can vary in sizefrom a small desktop model to the size of a small filing cabinet. A typicalmini system is more expensive than a PC and surpasses of PC in storagecapacity and speed. While most PCs are oriented towards single users, minisystems are designed to handle the needs of multiple users, i.e., more thanone person can work on a mini at the same time.Mainframe ComputersA mainframe is another form of a computer system that is generally morepowerful than a typical mini. Mainframes themselves may vary widely in costand capability. They are used in large organizations for large scale jobs.However, there is an overlap between the expensive minis and smallmainframe models in terms of cost and capability.Super computersAt the end of the size and capability scale, are the super computers. Thesesystems are the largest, fastest and most expensive computers in the world.These computers are owned by large organizations. They are used forcomplex scientific applications.Special purpose and general purpose computers 5. You have read about the applications and types of computers. Computers canalso be categorized general purpose computers and special purposecomputers, depending on their area of application.Special purpose computers are designed to perform specific functions only.Computers used in industrial process control, for example, in a washingmachine, a space craft, or a robot fall under this category.General purpose computer on the other hand, are fast data manipulatingsystems. They are designed to automatically accept and store input data,process it, and output the information. Computers used in scientificapplications weather forecasting, research and business data-processing likepayroll fall under the general purpose category.DATA AND INFORMATIONThe word data is plural datum, which means fact or raw information.Information is organized or processed data. For example, 88, 99, 34 arenumbers i.e., data. But they alone do not give any information as to whatthey are. However, if they are written asSubject MarksEnglish 88Mathematics 99History 34then they become meaningful and are referred to as information.WorkingWorking principle of a computerJust as a human being can be seen as a combination of body and mind, so cana computer. The computer is a two part system consisting of a body that isthe hardware and a mind that is the software. A computer therefore, is acollection of electronic parts (body) with a set of instructions controlling it(mind).Most activities can be described in terms of the Input-Process-Output (I-P-O)cycle. This can be best illustrated by an example.Let us assume that, you are asked to add 1346 and 29363You first hear the two numbers.3Store the numbers in your memory. 6. 3 Your brain adds the two numbers.3 Then, the result (4281) is stored in your memory.3 You either speak out the result or write it down depending onrequirement.The numbers are input, added and the result is output here, the inputs are1346 and 2935. the output is 4281. Your ear is the input device, brain is theprocessing unit, and mouth is the output device.A computer system too, follows the I-P-O cycle. To understand the I-P-O cycleof a computer, let us take the example of an airline reservation system.A person who wishes to travel by air from Singapore to New York fills in areservation request slip. This slip contains relevant data, i.e., details of thename, age, place of destination, etc., of the customer. These customer detailsare the inputs. The process in this case, included examining the flightnumber, the date of the journey, the class requested, and determiningwhether seats are available as per the reservation details.As a result of this process, the information that either the person gets thereservation or is unable to get the reservation is output. The output may bein the form of a ticket, if seats are available, or a message turning down therequest. Incase the customer is given reservation, his details are stored in astorage device.Now, let us see how each component of the PC system is related to the I-P-Ocycle. The data in the form of request slip is input via the keyboard. Hence,the keyboard becomes the input device. The processing is performed by acomponent of the system unit called the microprocessor.The information regarding availability of seats is displayed on the displayunit; Hence, the VDU becomes the output device. If a ticket is to be issued, itis printed on a printer which is also an output device.Thus, each component of the PC system is involved in the I-P-O cycle. Thesystem unit does the processing. The other components -the VDU, theprinter, and the keyboard are necessary in the input or output part of the I-P-O cycle and are hence termed as I/O devices. Now you can identify thecomponents of a PC as:i.The monitor or the visual display unit (VDU) for outputii. The keyboard for input 7. iii. The system unit (CPU) for processingiv.The printer for outputHARDWARE AND SOFTWAREComputer hardware includes all the electrical, mechanical, and the electronicparts of a computer. Any part that we can see or touch is the hard ware.Computer hardware includes3System Unit3Peripheral devices3Input devices i.e. keyboard, mouse etc.3Output devices i.e. Display Unit, printer etc.3Storage devices like hard disk, floppy disks etc.Software:The functioning of the computer is not dependent on hardware alone. So,what else is required?It requires a set of instructions that tells the computer what is to be donewith the input data. In computer terminology, this set of instructions is calleda program and one or more programs is termed as software.Let us understand hardware and software with an example. An audiocassette when played gives you some sound. Here, the tape recorder and theaudio cassette can be compared to hardware. The sound which comes fromthe tape recorder can be compared to software.Software used for computers may be of different types. Some of which are :3Application Software3System Software 8. You read about application of computer and identified certain areas wherecomputers are used today.Applicatioin SoftwareSoftware specially suited for specific applications for example, railway andairline reservation, billing, accounting or software which enables creationand storage of documents are termed as application software