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Computer fundamentalUNIT: 1 INTRODUCTION TO COMPUTER1. WHAT IS COMPUTER? The word “computer” is comes from the word “TO COMPUTE” means tocalculate. A computer is normally considered to be a calculation device which can performthe arithmetic operations very speedily. A computer may be defined as a device which operates upon the data. Data can be in the form of numbers, letters, symbols, size etc. And it comes invarious shapes & sizes depending upon the type of computer application. A computer can store, process & retrieve data as and when we desired. The fact that computer process data is so fundamental that many people havestarted calling as “Data Processor”. A computer first it gets the Data, does Process on it and then producesInformation.DATA PROCESSINFORMATIONDEFINATION OF COMPUTERo A computer is an electronic device which takes input from the user,processes it and gives the output as per user’s requirement.o So the main tasks of performed by the computer are: Input Process Output2. WRITE DOWN THE CHARACTERISTICS OF COMPUTERSome important characteristics of the computer are as follow: Automatic:o Computers are automatic machines because it works by itself withouthuman intervention.o Once it started on a job they carry on until the job is finished.o Computer cannot start themselves.1Prepared By: Meghna Bhatt

o They can works from the instructions which are stored inside the system inthe form of programs which specify how a particular job is to be done.Accuracy:o The accuracy of a computer is very high.o The degree of accuracy of a particular computer depends upon its design.o Errors can occur by the computer. But these are due to human weakness,due to incorrect data, but not due to the technological weakness.Speed:o Computer is a very fact device. It can perform the amount of work in fewseconds for which a human can take an entire year.o While talking about computer speed we do not talk in terms of secondsand milliseconds but in microseconds.o A powerful computer is capable of performing several billion (109) simplearithmetic operations per second.Diligence:o Unlike human beings, a computer is free from monotony, tiredness & lackof concentration.o It can continuously work for hours without creating any error & withoutgrumbling.o If you give ten million calculations to performed, it will perform withexactly the same accuracy & speed as the first one.Versatility:o It is one of the most wonderful features about the computer.o One moment it is preparing the results of a particular examination, thenext moment it is busy with preparing electricity bills and in between itmay be helping an office secretary to trace an important letter in seconds.Power of remembering:o Computer can store and recall any amount of data because of its highstorage capacity of its storage devices.o Every piece of information can be retained as long as desired by the userand can be recalled as and when required.o Even after several years, if the information recalled, it will be as accurateas on the day when it was filled to the computers .No I.Q.o A computer is not a magical device; it processes no intelligence of its own.o Its I.Q. is zero.2Prepared By: Meghna Bhatt

o It has to be told what to do & in what sequence.o It cannot take its own decision. No Fallings:o A Computer has no feelings because they are machines.o Based on our feelings, task, knowledge and experience we often makecertain judgments in our day today life.o But Computer goes exactly the way which we have given the instructions .3. EXPLAIN THE DATA PROCESSING CYCLE OFCOMPUTER. The computer Data Processing is any process that a computer program does toenter data & summarise, analyse or convert data into useable information. The process may be automated & run on a computer. It involves recording, analysing, storing, summarising & storing data. Because data are most useful when it is well presented & informative.The Data Processing Cycle: Data Processing cycle described all activities which are common to all dataprocessing systems from manual to electronic systems. These activities can be grouped in four functional categories, viz., data input,data processing, data output and storage, constituting what is known as a dataprocessing cycle. The main aim of data processing cycle is to convert the data into meaningfulinformation. Data processing system are often referred to as Information System. The Information System typically take raw Data as Input to produce Informationas Output.DATAINPUTPROCESSOUTPUTINFORMATIONSTORAGE The data processing cycle contains main four functions:o Data input3Prepared By: Meghna Bhatt

o Data processo Data storageo Data outputDATA INPUTo The term input refers to the activities required to record data.o It’s a process to entered data in to computer system.o So before we input any data, it is necessary to check or verify the datacontext.DATA PROCESSINGo The term processing includes the activities like classifying, storing,calculating, comparing or summarising the data.o The processing means to use techniques to convert the data intomeaningful information.DATA OUTPUTo It’s a communication function which transmits the information to theoutside world.o After completed the process the data are converted into the meaningful ino Sometimes the output also includes the decoding activity which convertsthe electronically generated information into human readable form.DATA STORAGEo It involves the filling of data & information for future use.4. EXPLAIN THE CLASSIFICATION OF THE COMPUTER BYDATA PROCESSEDThe computers are divided mainly three types on the based on data processed:1. Analog computers2. Digital computers3. Hybrid computersAnalog computers: In Analog Computers, data is represented as continuously varying voltage andoperate essentially by measuring rather counting. As the data is continuously variable, the results obtained are estimated and notexactly repeatable. It can able to perform multiple tasks simultaneously and also capable to workeffectively with the irrational number. E.g. 1/8 0.125 and 1/6 0.16664Prepared By: Meghna Bhatt

Voltage, temperature and pressure are measured using analog devices likevoltmeters, thermometers and barometers.Digital Computers The digit computer is a machine based on digital technology which representsinformation by numerical digit. In Digital Computers data is represented as discrete units of electrical pulses. Thedata is measured in quantities represented as either the ‘on’ or ‘off’ state. Therefore, the results obtained from a digital computer are accurate. Virtually all of today’s computers are based on digital computers.Hybrid Computers It combines the good features of both analog & digital computers. It has a speed of analog computer & accuracy of digital computer. Hybrid Computers accept data in analog form and present output also indigitally. The data however is processed digitally. Therefore, hybrid computers require analog-to-digital and digital-to-analogconverters for output.5. EXPLAIN THE CLASSIFICATION OF THE COMPUTER BYDATA PROCESSING:The computers are classified in four types on the based on data processing. Micro computer Mini computer Mainframe computer Super computerMicro Computer: Micro computers are the computers with having a microprocessor chip as itcentral processing unit. Originated in late 1970s. First micro computer was built with 8 bit processor. Microcomputer is known as personal computer. Designed to use by individual whether in the form of pc’s, workstation ornotebook computers. Small in size and affordable for general people. Ex: IBM PC, IBM PC/XT, IBM PC/AT5Prepared By: Meghna Bhatt

Micro Computer: Mini computers are originated in 1960s. Small mainframes that perform limited tasks. Less expensive than mainframe computer. Mini computers are Lower mainframe in the terms of processing capabilities. Capable of supporting 10 to 100 users simultaneously. In 1970s it contains 8 bit or 12 bit processor. Gradually the architecture requirement is grown and 16 and 32 bit. Minicomputers are invented which are known as supermini computers. Ex: IBM AS400Mainframe Computer: A very powerful computer which capable of supporting thousands of usersimultaneously. It contains powerful data processing system. It is capable to run multiple operating systems. It is capable to process 100 million instructions per second. Mainframes are very large & expensive computers with having larger internalstorage capacity & high processing speed. Mainframes are used in the organization that need to process large number oftransaction online & required a computer system having massive storage &processing capabilities. Mainly used to handle bulk of data & information for processing. Mainframe system is housed in a central location with several user terminalconnected to it. Much bigger in size & needs a large rooms with closely humidity &temperature. IBM & DEC are major vendors of mainframes. Ex : MEDHA, SPERRY, IBM, DEC, HP, HCLSuper Computer: Most powerful & most expensive computer. Used for complex scientific application that requires huge processing power. Used multiprocessor technology to perform the calculation very speedy. They are special purpose computers that are designed to perform somespecific task.6Prepared By: Meghna Bhatt

The cost of the super computer is depended on its processing capabilities &configuration. The speed of modern computer is measured in gigaflops, teraflops andpetaflops.o Gigaflops 109 arithmetic operation per second.o Teraflops 1012 arithmetic operation per second.o Petaflops 1015 arithmetic operation per second. Ex: PARAM , EKA, BLUE GENE/P6. EXPLAIN THE GENERATION OF THE COMPUTERS.In Computer language, “Generation” is a set of Technology. It provides a frameworkfor the growth of the computer technology. There are totally Five Computer Generationstill today. Discussed as following.First Generation: Duration:1942-1955 Technology: vacuum tubeo Used as a calculating device.o Performed calculations in milliseconds.o To bulky in size & complex design.o Required large room to place it.o Generates too much heat & burnt.o Required continuously hardware maintenance.o Generates much heat so must air-conditioner rooms are required.o Commercial production is difficult & costly.o Difficult to configure.o Limited commercial use.o ENIAC, EDVAC, EDSAC are example of 1st generation computer.Second Generation: Duration:1955-1964 Technology:transistoro 10 times Smaller in size than 1st generation system.o Less heat than 1st generation computers.o Consumed less power than 1st generation system.o Computers were done calculations in microseconds.o Air-conditioner is also required.o Easy to configure than 1st generation computers.7Prepared By: Meghna Bhatt

o More reliable in information.o Wider commercial use.o Large & fast primary/secondary storage than 1st generation computers.Third Generation: Duration:1965-1975 Technology: IC chipo Smaller in size than 1st & 2nd generation computers.o Perform more fast calculations than 2nd generation systems.o Large & fast primary/secondary storage than 2nd generation computers.o Air –conditioner is required.o Widely used for commercial applications.o General purpose computers.o High level languages like COBOL & FORTAN are allowed to write programs.o Generate less heat & consumed less power than 2nd generation computer.Fourth Generation: Duration:1975-1989 Technology: Microprocessor chipo Based on LSI & VLSI microprocessor chip.o Smaller in size.o Much faster than previous generations.o Minimum hardware maintenance is required.o Very reliable as computer to previous generation computers.o Totally general purpose computer.o Easy to configure.o Possible to use network concept to connect the computer together.o NO requirement of air-conditioners.o Cheapest in price.Fifth Generation: Duration:1989 to Present Technology: ULSI microprocessor chipo Much smaller & handy.o Based on the ULSI chip which contains 100 million electronic components.o The speed of the operations is increased.o Consumed less power.o Air-conditioner is not required.o More user friendly interface with multi-media features.o High level languages are allowed to write programs.o Larger & faster primary/secondary storage than previous generations.8Prepared By: Meghna Bhatt

o Notebook computers are the example of 5th generation computers.7. EXPLAIN THE BLOCK DIAGRAM OF COMPUTER OREXPLAIN THE SIMPLE MODEL COMPUTER.A simple computer system comprises the basic components like Input Devices, CPU(Central Processing Unit) and Output Devices as under: Input Devices:o The devices which are used to entered data in the computer systems areknown as input devices.o Keyboard, mouse, scanner, mike, light pen etc are example of input devices.FUNCTION OF INPUT DEVICESo Accept the data from the outside worlds.o Convert that data into computer coded information.o Supply this data to CPU for further processing. Output Devices:o The devices which display the result generated by the computer are known asoutput devices.o Monitor, printer, plotter, speaker etc are the example of output devices.FUNCTIONS OF OUTPUT DEVICESo Accept the result form the CPU.o Convert that result into human readable form.9Prepared By: Meghna Bhatt

o Display the result on the output device. Memory Unit:o The data & instruction have to store inside the computer before the actualprocessing start.o Same way the result of the computer must be stored before passed to theoutput devices. This tasks performed by memory unit.FUNCTIONS OF MEMORY UNITo Store data & instruction received from input devices.o Store the intermediate results generated by CPU.o Store the final result generated by CPU. Arithmetical & Logical Unit:o The ALU is the place where actual data & instruction are processed.o All the calculations are performed & all comparisons are made in ALU.o Performs all arithmetical & logical operations.o An arithmetic operation contains basic operations like addition, subtraction,multiplication, division.o Logical operations contains comparison such as less than, greater than, lessthan equal to, greater than equal to, equal to, not equal to. Control Unit:o It controls the movement of data and program instructions into and out ofthe CPU, and to control the operations of the ALU.o In sort, its main function is to manage all the activities within the computersystem.o Controls the internal parts as well as the external parts related with thecomputer. CPU:o The Unit where all the processing is done is called as Central Processing Unit.o It contains many other units under it.o Main of them are:- Control Unit And ALU (Arithmetic & Logic Unit)10Prepared By: Meghna Bhatt

UNIT: 2 INPUT DEVICES1. WHAT IS INPUT DEVICES? The Input devices are the devices which are used to enter the data in thecomputer system. Keyboard, mouse, sca

The computers are classified in four types on the based on data processing. Micro computer Mini computer Mainframe computer Super computer Micro Computer: Micro computers are the computers with having a microprocessor chip as it central processing unit. Originated in late 1970s.