booklet of computer

8/7/2019 Booklet of Computer.

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COMPUTER

April 10

2011In this booklet I have tried my level best to provide basic information about

computer for beginners.

Basics of

Computer


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Introduction to Computer Science

COMPUTERComputer is an electronic machine, which accepts data, process on that data and provides suitableresult and store data for the future use. The word COMPUTER is derived from Latin wordCOMPUTE which means to CALCULATE

THERE ARE THREE MAIN PARTS OF COMPUTER

1. INPUT UNITa. Keyboard

b. Mousec. Scanner

2. CPU= CENTRAL PROCESSING UNITIt is Composed of Three Unit

CU= Control Unit ALU= Arithmetic Logic Unit MU=Memory Unit (RAM, ROM)

Brain of Computer3. OUTPUT UNIT

a. Monitorb. Printerc. Speaker

THERE ARE TWO MAJOR COMPONEN TOF COMPUTER

1. Hardware2. Software

1. HARDWARE

The physical component of computers and other attached input / output devices are called hardware.ORThe equipment associated with computer system is called HardwareExample: Keyboard, Central Processing Unit, Monitor, Mouse etc.

2. SOFTWAREThe set of instruction that tells the hardware what to do is called softwareExample: Ms-Office, Photo shop, Coral Draw EtcThere are two main types of software

1.

System Software2. Application Software

1. System Software

That software by which computer boot is called system softwareThe program directly related to the hardware of computer and which perform the fundamental tasks iscalled system software. A number of programs may be included in system software but following areessential for any computer.

Operating system e.g. Windows Xp ,Unix etc Editors we can typed, modified program Language Translators Compiler, Interpreter, Assembler. Utilities Debuggers, defragmenters, memory managers, virus detectors etc


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Introduction to Computer Science Linkers Create best link to object program Loaders Load the program form disk to memory for execution

System perform to basic functions It create environment b/w user and computer It maintain all the resources of computer

2. Application software

That software by which user achieve his own task is called Application softwareThere are two main types ofApplication software

1. General purpose2. Special purpose

1. General purpose Application software

To perform general task or by using such software we can fulfill our general need. Such Ms Office,graphical animation Photo shops etc that is called general purpose application software.

2. Special purpose Application softwareSuch Software that is developed for the specific needs and requirement for an organization orcompany is called special purpose application. For example Bank software, Medical store software.Insurance companys software etcDATA

Collection of raw facts and figures are called DataUnprocessed data or any thing before processing is called Data. Data can exist in many formsComputers can handles four types of data. Text, graphics, audio and video data.INFORMATION

Collection of meaningful data is called InformationProcessed data or meaningful data or any thing after processing is called information

Data + Process (Structure) = Information

IMPORTANCE OF COMPUTER OR WHERE COMPUTER IS USEDToday ComputerAre Used In Accounting Record Keeping, Education, Science, Biomedical, Aerospace Business, Etc

In Industry computers are used in manufacturing units for control it. Like computerized printingmachine in which special purpose computer is used to work speedily, save time and money. AlsoX-rays machine and wheel balance machine etc. are the example of special purpose computer which

pays important role in our life. In business, Computer is used for record keeping, for inventory controletc. In the modern age of computer, we can see all aerospace companies have their computerizedsystem. Aero- plane flies with the help of computer. For link in between one plane to another or planeto tower we use satellites for which computer is essential. Also computer can be a used in science and

biomedical field for researches computer saves our time, which is also prime importance.

The various fields computer are used some are given as under

1. Scientific


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Introduction to Computer Sciencea) Predication of weatherb) Predication of earth quakesc) Satellite Controlling

2. Engineeringa) Design of car, airplane or shipb) Design of a building or bridgec) Design of a new tool

3. Businessa) Word Processingb) Record Keepingc) Inventory controld) Pay roll processinge) Forecastingf) Planningg) Accountingh) Auditingi) Stock Marketingj) Ticket Reservation

4. Robotica) Welding or heavy machinesb) Soldering or electronic componentsc) Fabricating a microprocessord) Loading and unloading parts from machinese) Searching defects in an itemf) Move item from one place to another place

5. Educationa) Learn Alphabets or numbersb) Describing the human biological systemc) Describing the basic arithmetic operationsd) Solving statistical probleme) Solving complex mathematical problems

6. Lawa) Keeping Record of criminalb) Keeping Record of courtsc) Keeping Record of decisions

7. Publishing

a) Compile news paperb) Design books, Brochures, posters, etc.c) Design wedding ,eid or visiting cards

8. Graphicsa) Prepare titles or slides for TV commercialb) Prepare cartoon filmsc) Preserve paintingsd) Drawing maps


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Introduction to Computer Science9. Entertainment

a) Play simple gameb) Play video and audio songs

10. Home computinga. Business work done at homeb. School worksc.Communication (E-mails)

11. Government

a. Population,b. Taxes ,c. Militaryd. Police Etc

Advantage of Computer or Capabilities of ComputerSome important capabilities or advantages are defined below.

1. SpeedThe most important advantage of computer over the human being is the speed with which it performInstructions. An older computer is capable to perform several thousand instructions per second. Whilea latest computer is capable to perform several million instruction per second.

2. AccuracyThe result of computer are much accurate than manual work. If one uses a computer to perform somecalculations the answer obtained would be accurate up to seventh decimal place

3. Storage CapabilityComputer system can store tremendous amount of data which can be located and retrieved efficiently.The capability to stored volume of data is especially important in an information age4. Diligence

Computer is performing repetitive jobs benignly it means computer never board with repetitive jobs

5. Run for Long PeriodComputer can operate with out failure for long period of time while a human has to exhaust after acertain period of time.6. Automatic Operation

In automatic mode the sequence of these operation stored in memory as a program7. Decision Making Capability

It is true that the computer can not think but the computer can take simple decision such as 15 isgreater than 10 or not. In the same way computer can decide that two values are equal or not.

8. Variety of TaskThe computer is capable of performing a wide variety of tasks

CLASSIFICATION OF COMPUTERComputer can be classified according to function, according to size and capacity and according topurpose. That is defined below.

Classification of Computer According To Function or Types of ComputerAccording to Function There are three major types of Computer.

1. Digital Computer2. Analog Computer3. Hybrid Computer

1. Digital Computer


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Introduction to Computer ScienceThose computers, which deals with discrete data, is called Digital Computer. Digital computers arehigh-speed programmable electronic machine that perform mathematical calculation.Example: - Microcomputer, Mini Computer, Mainframe Computer and Super Computer are theexample of Digital Computer

2. Analog ComputerThose computers, which deal with continuous physical data, are called Analog Computer.

An Analog Computer is an electronic machine that measure physical values such as temperature orpressure that all along a continuous scale, Circular motion, distance, velocity of sound and voltage.

Example: - A service station petrol pump contains an analog processor that converts fuel flowmeasuring in quantity and price.

3. Hybrid Computer

Hybrid Computer is the combination ofAnalog and Digital Computer. Hybrid computer represent data both discrete and approximately. Hybrid computers contains feature of both analog and digitalcomputer

Example: - ECG machine, Electronic fuel pump, digital speedometer, Electronic weight Balance etc

Classification of Computer According to Size and CapacityWhen we classify the computerAccording to size and capacity there are four major computers areincluded.

1. Micro Computer2. Mini Computer3. Mainframe Computer4. Super Computer

1. Micro Computer

Microcomputer is sometime called personal computer. It is small in size and capacity. Amicrocomputer consists of two basic systems. One is central processing unit. And other is peripheralsubsystem. The Central Processing Unit composed of internal memory (RAM -ROM). Arithmeticlogic unit and control unit. The peripheral subsystem consist of input, output and mass storage device.Microcomputer is used in small companies. Banks, educational institution and at home

Note Book (Laptop computer) handheld computer, desktop computer are types of microcomputer

Cost: 1000 dollars to over 5000 dollarSpeed: speed depends on processor installed in the computer (30 million instructions per

second) approximatelySize DesktopProcessing Memory: 4- 128MB

2. Mini Computer

Minicomputer has small storage capacity and slow processing speed comparatively Mainframecomputer and much more storage capacity and high processing speed comparatively Microcomputer.Minicomputers are used to perform intensive calculation let many terminal to share the same data

Cost: 25000 dollars to over 150,000 dollarSpeed: 150 million instructions per seconds

Size Filling cab net sizeProcessing Memory: 32- 256MB


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Introduction to Computer Science3. Mainframe Computer

Mainframe computers are large in size, storage capacity and high processing speed. The mainframecomputers are designed to handle tremendous amount of input, output and mass storage. A mainframecomputer has more than one arithmetic logic unit and control unit.IBM-370, DEC-10000, IBM ES-2 are some mainframe computers.Mainframe computers are used in large organization such as Bank, airline, and insurances companies,

government agencies, universities, and college for processing million of transaction.

Cost: Several thousand dollars

Speed: 250 million instructions per secondsSize Refrigerator Size

Processing Memory: 64- 1024MB

4. Super ComputerSuper computers are the largest, fastest and most expensive computer. Supercomputer can handles

over 10,000 users. Super computer are based on the principle of parallel processing. Super computershave capabilities to understand the symbol, graphs and even human speech. A supercomputer mayhave many processing units which working together to perform a billion of instruction or more

scientific arithmetic operation in second. Super computer are manufactured by Cray Corporation inUSA. They are

Cray-1, Cray-2, Cray-3, Cray-xmp, Cray-T90, Cray-C90, Cray-T3-E, EtcSuper computer are used for solving the complex application such as global weather forecasting,creating graphic images, engineering design and testing and space exploration. Super computer arealso used for top secret weapons, researches, calculation of governments, scientific laboratorySuper computer are designed to process scientific applications

Cost: Several Million dollars

Speed: 60 Billion instructions per secondsSize Automobile or Refrigerator/Box size

Processing Memory: 8- 192 GB

Classification of Computer According to PurposeWhen we classify the computer according to purpose then there are two major purpose of computer

1. General Purpose2. Special Purpose

1. General Purpose of computerGeneral Purpose of computer is those computers which have a many to task to perform at a time. Just

like our PC (Personal Computer) systems which can perform multiple task for example it can solve themathematical calculation and it can process on word through word processors. It can be used in many

fields like health, financial Institutions, Industries. Military ETC.

2. Special Purpose of ComputerSpecial purpose computer are those computers which can perform on task at a time. These computerwere built for only one purpose, For Example Petrol Pump machine, it can measures the petrol thathow much petrol wastage. X-rays machine and wheel balance machine etc. are the example of special

purpose computer

Generation of ComputersEach new generation has seen the following changes in computer characteristic.

Increase in speed Increase in storage capacity


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HISTORY AND DEVELOPMENT OF COMPUTEROr GENERATION OF COMPUTER

Period 1st

Generation1942-1955

2nd

Generation1955-1964

3rd

Generation1964-1975

4th

Generation1975-1990

5th

Generation1990-onward

Internalcomponent of

computer Tech:

Vacuum Tube Transistors IntegratedCircuit (LSI)

MicroprocessorVLSI

Furtherimprovement in

Microprocessor

Size of computer Very LargeMainframe

computer

Smaller than1st Generation

computer

Much smallerthan 2nd

generationComputer

Very SmallComputer

Laptop

Tiny ComputerDiary

Speed of the

computer

Low speed

computer

Ten time faster

than 1st

generation

100 time faster

than 2ndgeneration

10 time faster

than 3rd

generation

Much faster than 4th

generation

Storage Device Magnetic Tape Magnetic tape Magnetic Disk

Hard Disk

Disk storage

Floppy Disk

Floppy Disk, Disk

Storage, CD-ROM

Main Memory MagneticDrum

ROMRAM

PROMDRAM

EPROMSRAM

EPROMSIMM

Language used

for Programming

Machine andAssemblylanguage

High LevelLanguageFortran, PL-1Cobol, Basic

Much EasierHigh LevelLanguageOOP, C++

Very HighLevel LanguageQuery languageVB,SQL ETC

ArtificialIntelligence

Natural Language

Typical Computer Mark1-EDVAC,

EDSAC,ENIAC,

UNIVAC-1IBM-650

IBM 1400,IBM 700,

GenericElectric-635,

CDC -6600and control

data 3600

IBM 360ICL 900,

PDP-5,PDP-8,

ETC

IBM 370 andIBM 4300

Cyber205,Apple,

commodoreETC


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CENTRAL PROCESSING UNIT (CPU)

CPU is the Abbreviation ofCentralProcessingUnit. The CPU is the brains of the computer.The Central Processing Unit (CPU) is a complex set of electronic circuitry that executes

program instruction. The CPU is the most important element of a computer system. The entireCPU is a single unit called microprocessor.This Unit is divided into four main parts as described.

1) Control Unit (CU)2)

Arithmetic Logic Unit (

ALU)3) Memory Unit (RAM, ROM)

4) Register1) Control Unit (CU)The control unit directs and coordinates all activities of a computer.The control unit is the most important part of the CPU. It controls and co-ordinates theactivities of all other units such as ALU, Memory Unit, Input and Output Unit. It is thecontrol unit which interprets instructions and transfers data from the main memory to theALU for processing.2) Arithmetic Logic Unit (ALU)The Arithmetic logic unit performs actual processing of data which includes addition,subtraction, multiplication and division. This unit also performs certain logical operationsuch as comparing two numbers to see one is greater than other or they are equal. In thisway computer is able to make simple decision.3) MEMORY UNIT (MU)In a computer, memory is one or more set of chips that store data or program instruction eithertemporarily or permanently.

Memory Unit is divided into two parts1. RAM= Random Access Memory2. ROM= Read Only Memory

1. RANDOM ACCESS MEMORY (RAM)

RAM is an abbreviation ofRandom Access Memory.Memory that provides temporary storage for data and program instruction is called Random accessMemory. RAM memory is a volatile meaning that if a computer loses power, shut off the contentsof its memory are lost. Therefore it is important frequently save any valuable work to secondarydisk storage. Random Access means that because each memory location has an individual addressthe computer can go directly to the instruction and data it wants. Using the address rather thansearching individual location one after another (Sequentially).RAM has a tremendous impact on the speed and power of computer. RAM memory is bothreadable and writable meaning that contents of any memory locations can be changed and or readat any time.


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There are two main types of RAM1. SRAM ( Static Random Access Memory)2. DRAM (Dynamic Random Access Memory)

Static RAM (SRAM)

Static RAM is a type of RAM that holds its data without external refresh, for as long as power issupplied to the circuit. SRAMs are used for specific applications within the PC, where their

strengths outweigh their weaknesses compared to DRAM:

y Speed: SRAM is faster than DRAM.y Cost: SRAM is, byte for byte, several times more expensive than DRAM.y Size: SRAMs take up much more space than DRAMsDynamic RAM (DRAM)

Dynamic RAM is a type of RAM that only holds its data if it is continuously accessed by speciallogic called a refresh circuit. The reading action itself refreshes the contents of the memory. If thisis not done regularly, then the DRAM will lose its contents, even if it continues to have powersupplied to it. This refreshing action is why the memory is called dynamic.All PCs use DRAM fortheir main system memory, instead of SRAM, In fact, DRAMs are both more complicated and

slower than SRAMs. DRAMs are smaller and less expensive than SRAM.

2. READ ONLY MEMORY (ROM)Computers almost always contain a small amount of read-only memory that holdsinstructions for starting up the computer. ROM chip store fixed startup instruction. UnlikeRAM, ROM cannot be written to.

PROM (Programmable Read-Only Memory):A

PROM is a memory chip onwhich you can store aprogram. But once the PROM has been used, you cannot wipe itclean and use it to store something else. Like ROMs, PROMs are non-volatile.

EPROM(Erasable Programmable Read-Only Memory):An EPROM is a specialtype of PROM that can be erased by exposing it to ultraviolet light.

EEPROM (Electrically Erasable Programmable Read-Only Memory): AnEEPROM is a special type of PROM that can be erased by exposing it to an electricalcharge


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INPUT DEVICES Input DeviceAny machine that feeds data into a computer is called Input Device.Input device are categorized as three types.

1. Keyboard2. Pointing Device3. Source Data Entry Device

1. KEYBOARDA keyboard is a device that converts letters, numbers and other characters into electricalsignals that can be read by the computers processor. Desktop computer consist of 104-108keys and Notebook computer consist of 85 keys.

TYPES OF COMPUTER1. QWERTY KEYBOARD

QWERTY keyboard developed by Sholes in 1868.

2. DVORAKKEYBOARDDVORAK keyboard developed by DR. August Dvorak in 1936

But still QWERTY Keyboard is official standard computer keyboard (ISO 9995) Due to thebest Alpha Keys arrangement.

KEY CATEGORIZED OF KEYBOARD

The Alphanumeric KeysIt consist Alphabet and Number keys The Modifier KeysThese keys modifies Input, shift, Alt(Alternate),ctrl (Control)

keys

The Function KeysThese keys used for input command directly.F1, F2 F12. The Cursor Movement Keys Numeric Keypad Special Purpose key star key, short cut keys

KEYBOARD WORKINGWhen a key press, Keyboard controller (a tiny chip) records the key and place its code

in keyboard buffer (its memory) and sends a signal to system then system reads the code of keyfrom location of keyboard buffer and process the request.

2. POINTING DEVICEPointing device control the portion of the cursor or pointer on the screen and allow the user to s

elect options displayed on the screen.I

t uses physical gesture, point, click and drag.

Types of Pointing Device Mouse Trackball Touchpad Pointing Stick Light Pen Touch screen Joystick


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MOUSEI

n computing, a mouse (plural mice ormousse) functions as a pointing device by detectingtwo-dimensional motion relatives to its supporting surface

Types of Mousey Mechanical Mouse: - It uses one ball and two rollers with one spring for movement

observation.

y Optical Mouse: - it uses a light emitting diode and photodiodes to detect movementrelatives to the underlying surface, rather than moving some of its parts- as inmechanical mouse.Optical mouse sensor processes 1512 frames per second. It has image processing chipto process frames on the basis of these frames coordinates are being calculated.

y LASER Mouse:- It uses a small laser instead of an LED which increase the resolutionof the image taken by the mouse

TRACKBALLA trackball is a pointing device consisting of a ball house in a socket containing sensors todetect rotation of the ball about two axes. ORThe Trackball is movable ball, mounted on top of a stationary device that can be rotatedusing your finger or palm.

y It mostly uses for CAD, as it can draw fine then mousey In Air Traffic control, Submarine.y Public Terminals, as easy to fix then mouse.TOUCH PAD

Atouchpad is a pointing input device commonly used in laptop computers. They are used tomove the cursor, using motions of the users finger. They are a substitute for a computermouse.

Capacitive sensors are re-laid out along the horizontal and vertical axes of thetouchpad.

The location of the finger is determined from the pattern of the capacitance (electriccharges) of finger.

POINTING STICKA Pointing Stick is an input device commonly used in laptop computers. They are used tomove the cursor. A pointing stick looks like a pencil eraser protruding form the keyboard

between the G, H, and B keys. When you move the pointing stick with your finger, the screenpointer moves accordingly. IBM developed pointing stick for use with its notebook computers.

The pointing stick operates by sensing applied force.y The velocity of the cursor depends on the applied force.y Pros over mouse and touchpad.

Very near to keyboard. Cursors motion is not dependant to on fingers motions

LIGHT PENA light pen is a pointing input device in the form of light sensitive wand used in conjunctionwith the computers CRT monitor. It allows the user to point to displayed objects, or draw onthe screen. OR


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Introduction to Computer ScienceThe light pen is a light sensitive pen-like device that uses a wired connection to a computerterminal.Light pens are used by engineers, graphic designers and illustrators.

Not for LCD screen, projections or other display devices.The light pen works by sensing thesudden small change in brightness of a point on the screen when the electron gun refreshes thatspot.Cons: holding arm in front of the screen for long periods of time.

TOUCH SCREENA touch screen is a video display screen that has been sensitized to receive input from thetouch of a finger. Touch screen device accept input by allowing user to place a finger tripdirectly on the screen.Touch screens also have assisted in recent changes in the design of personal digital assistant(PDA), satellite navigation and mobile phone devices, making these devices more usable

JOYSTICKAjoystick is a control device consisting of a handheld tick that pivots about one end andtransmits its angle in two or three dimension to a computer.

Joy sticks are often used to control games. Joy sticks are also used for controlling machines such as elevators, cranes, trucks and

powered wheelchairs.

MICROPHONEMicrophone, sometimes referred to as a mike is an acoustic to electric transducer or sensorthat converts sound into an electrical signal.It takes analog signal, sound waves and transfer to computerA sound Card is required for converting signal from analog signal and digital format.This process termed as digitizing. Used for audio recording and video conferencing.

WEB CAMERAA web camera (orWebcam, real camera) is a real time camera (usually, though not alwaysa video camera) whose image can be accessed using the world Wide Web, or a PC videocalling application like Video conferencing. It can be using for image as well a video transfer.

SOURCE DATA ENTRY DEVICES Scanner Barcode Reader Mark & Character Recognition Devices Fax machine

SCANNERA scanner converts graphic and pictorial data to digital (binary form) which can be directlyfeed and store in a computer. Scanners or Optical scanners are use light sensing (optical)equipment to translate images of text, .photos into digital form.In computing, a scanner is a device that analyzes images, printed text, or handwriting, or an

object (such as an ornament) and converts it to a digital image.There are three types of scanner

y Flatbed Scannery Sheet feed Scannery Handheld Scanner

FLATBED SCANNERA flatbed scanner or Desktop scanner which works much like a photocopier. The image beingscanned is placed on a glass surface, where it remains stationary, and the scanning beam movesacross it. They are used to scan simple drawing. Graphs, charts etc. Flatbed scanners arecostlier and more powerful.

SHEET FEED SCANNER


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Introduction to Computer ScienceIn a sheet feed scanner motorized rollers feed the sheet across the scanning headLarger scanners include machines into which you can feed sheets of paper. These are called

sheet-fed scanners. Sheet-fed scanners are excellent for loose sheets of paper, but they areunable to handle bound documents.

HANDHELD SCANNERHandheld scanner is very small in size .the picture is place on a flat surface and the scanner ismoved downward by hand onto that picture to start scanning. Hand-held scanners are adequate

for small pictures and photos, but they are difficult to use if you need to scan an entire page oftext or graphics.

BARCODE READERAbarcode reader (orbarcode scanner) is an electronic device for reading printed barcodes.

Like a flatbed scanner, it consists of a light source, a lens and a photo conductor translatingoptical impulses into electrical ones. Barcode Readers are photoelectric (optical) scanners that

translate the symbols in the bar code into digital code. in this system, the price or a particularitem is set within the stores computer.

MARK-RECOGNITION AND CHARACTER RECOGNITION DEVICEThese are three types of scanning devices that sense marks or characters. They are usuallyreferred to by their abbreviations- MICR, OMR and OCR.

Magnetic - Ink Character Recognition (MICR) Optical Mark Recognition (OMR) Optical Character Recognition (OCR)

MAGNETIC - INKCHARACTER RECOGNITION (MICR)Magnetic Ink Character Reorganization, or MICR, a character recognition technology adoptedmainly by the banking industry to facilitate the processing of cheques. Magnetic Ink CharacterRecognition, or MICR, is a character recognition system that uses magnetizable ink ad specialcharacter.

OPTICAL MARKRECOGNITION (OMR)Optical-Mark Recognition (OMR) uses a special scanner that reads bubble marks andconverts them into computer usable form. The best well known example is the OMRtechnology used to read GRE and SAT Test. Or multiple choice question. In these cases thescanner read pencil marks that fill in circles or bubbles, on specially designed documents.OMR is also used in form and surveys.

OPTICAL CHARACTER RECOGNITION (OCR)Optical Character Recognition (OCR) is the mechanical or electronic translation of images ofhandwritten or typewritten text (usually captured by a scanner) into machine-editable text. OrSoftware converts scanned text from images (picture of the text) to an editable text format(usually ASCII) that can be imported into a word processing application and manipulated.OCR characters appear on utility bills and price tags on department store merchandise. Thewand reader is a common OCR scanning device.

FAX MACHINE

A fax-machine or Facsimile transmission machine scans an image andsends it as electronicsignals over telephone lines to receiving fax machine which prints out the image on printer.Fax-machine Short forfacsimile machine, a device that can send or receive pictures and textover a telephone linefax machine translates a picture into a series of zeros and ones (called a

bit map) that can be transmitted like normal computer data


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OUTPUT DEVICES Output Device

All those devices which is used to see the result (output) of the computer is called Outputdevice. The output device can be divided into two categories.

1. Soft Copy Device2. Hard Copy Device

Soft Copy deviceSoft copy is data that is shown on a display screen or is in audio or voice form. It exists

electronically. This kind of output is known as not tangible or it can not be touched. Monitor,Display screen is an example of Soft copy device.

Hard Copy deviceHard Copy is printed output. Hard copy is data that is shown on a Printer as printed form. Thiskind of output is known as tangible or it can be touched. Printer is an example of hard copydevice.

MONITORA display screen used to provide computer output to user is called Monitor Example includeCathode Ray Tube (CRT) Monitor, Flat Panel monitor and Liquid Crystal Display MonitorQuality of monitor is determined by two hardware

1. Monitor itself2. Video Controller

There are two Categories by the way monitor display color

1. Monochrome monitor2. Color Monitor3. Gray Scale Monitor

MONOCHROME MONITOR

A monitor that display only one color (such as Green, Amber and White) against contrasting

background which is usually BlackCOLOR MONITOR

A computer monitors whose screen can display data in color. A Colors monitor capabilitiesare based on a variety of factors current high resolution color monitors can display more than16 million colors but they also can be set to display as few 16 color or varying shades of gray.GRAY SCALE MONITOR

A monitor that display shades of gray on white or off-white background.

TYPES OF MONITORThere are basic two types of monitor

1. Cathode Ray Tube (CRT) monitor2. Flat Panel Display/ Liquid Crystal Display (LCD) Monitor

1. CATHODE RAY TUBE (CRT) MONITORA Cathode Ray Tube (CRT) is a vacuum tube used as a display screen in a computer or videodisplay terminal. ORA Cathode Ray Tube (CRT) is a type of monitor that uses a vacuum tube as a display screen.CRT monitor are mostly & commonly used with desktop computer

2. FLATE PANEL DISPLAY MONITORSA thin, light weight monitor is used in Laptop computer and notebook computer. Most Flat

panel display uses LCD Technology. Several types of Flat Panel but most common used isLiquid Crystal Display (LCD).


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LIQUID CRYSTAL DISPLAY (LCD).A flat panel monitor on which an image is created when the Liquid Crystal Display becomescharged used primarily in Notebook. LCD uses a special kind of liquid crystal display that isnormally transparent but becomes opaque when charges with electricity.

PRINTERPrinter is an output device that produces text and graphics on paper. A printer receives theinformation from the computer and prints that information on the paper.

MAJOR TYPES OF PRINTERPrinters are classified into two categories.

1. Impact Printer2. Non- Impact Printer

1. IMPACT PRINTERImpact Printer is a printing device that prints the information by striking against the paper.

Impact printers include all printers that work by striking an ink ribbon. Daisy wheel, dotmatrix, and line printers are impact printers.

1.

DOT MATRIX PRINTER2. DAISY WHEEL PRINTER3. LINE PRINTER

DOT MATRIX PRINTERDot Matrix Printer Creates characters by striking pins against an ink ribbon. Each pin makes a

dot, and combinations of dots form characters and illustrations. ORA type of printer that produces characters and illustrations by striking pins against an inkribbon to print closely spaced dots in the appropriate shape. Dot-matrix printers are relativelyexpensive and do not produce high-quality output. However, they can print to multi-pageforms (that is, carbon copies), something laser and ink-jet printers cannot do.Dot-matrix printers vary in two important characteristics:

Speed: Given in characters per second(cps), the speed can vary from about 50 to over 500

cps. Most dot-matrix printers offer different speeds depending on the quality of print desired.Print quality: Determined by the number of pins (the mechanisms that print the dots), it canvary from 9 to 24. The best dot-matrix printers (24 pins) can produce near letter-quality type,although you can still see a difference if you look closely.

DAISY WHEEL PRINTERDaisy-wheel printer - like a typewriter but with the preformed letters on the ends of spokes toform a wheel. The letters strike an inked ribbon onto paper. They are very slow 1/2 PPM (page

per minute). Very noisy and can only print the characters provided on the wheel and nographics (line drawings, pictures).

LINE PRINTERA line printer can print an entire line at a time, which normally covers 80 or 132 characters per

second. Therefore these printers have 80 or 132 printing head for each character.A

normal lineprinter can print 2500 line per minute

PLOTER

A plotter is a printer that interprets commands from a computer to make line drawings on paperwith one or more automated pens. Unlike a regular printer, the plotter can draw continuous

point-to-point lines directly from vector graphics files or commands. They are used in

engineering applications where precision is mandatory.


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2. NON IMPACT PRINTERA printer that prints without striking the paper; for example, a laser printer or an inkjet printer.

Non-impact printers are quieter than impact printers, ORA type of printer that does not operate by striking a head against a ribbon. Examples of non-impact printers include laser and ink-jet printers. The term no impactis important primarily inthat it distinguishes quiet printers from noisy (impact) printers.

1. LASER PRINTER2. INKJET PRINTER3. THERMAL PRINTER

LASER PRINTERLaser printer is a type of printer that utilizes a laser beam to produce an image on a drum. Thelight of the laser alters the electrical charge on the drum wherever it hits. The drum is then

rolled through a reservoir of toner, which is picked up by the charged portions of the drum.Finally, the toner is transferred to the paper through a combination of heat and pressure ORLaser printers are non-impact printers which can print text and images in high speed and highquality resolution, ranging from 600 to 1200 dpi.The LASER (Light Amplification by Stimulated Emission of Rays) printers are quiet and

produce high quality output. Laser printer use toner (Black or Colored powder) instead ofliquid inks. A laser printer consists of these major components: drum cartridge, rotating mirror,toner cartridge and roller. The drum cartridge rotates as the paper is fed through. The mirrordeflects laser beam across the surface of the drum. Laser beam creates charges the causes thetoner to stick to the drum. As the drum rotates and presses on paper, tone to paper. Coloredlaser printers add colored toner in three additional passes

INKJET PRINTERInk jet printers are non-impact printers which print text and images by spraying tiny dropletsof liquid ink onto paper. They are the most popular printers for home use.

Inkjet printers are a type of computer printer that operates by propelling tiny droplets ofliquid ink onto paper. Inkjet printers spray onto paper small, electrically charged droplets of

ink from four nozzles through holes in a matrix at high speed. The ink jet printers have a dpi300 to 2400 and spray ink onto the page a line at a time, in both high quality black and white

text and high quality color graphics. There are three main technologies in use in contemporaryinkjet printers: thermal, piezoelectric, and continuous.

THERMAL PRINTERThermal printers are using colored waxes and heat elements to produce images by burning dotsonto special. Thermal printer used ribbons that hold the ink (a wax binder ), and as the hot pins

in thermal print head press the ribbon against the paper the wax melts and the ink intransferred to the paper.

SPEAKERSpeaker is an output device. An electro-acoustic transducer that converts electrical signals intosounds loud enough to be heard at a distance


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Storage devices

Astorage device is a hardware device designed to store information. There are two types ofstorage devices used in computers; a 'primary storage' device and a 'secondary storage' device.PRIMARY STORAGE

A storage location that holds memory for short periods of times. For example, computerRAMis an example of a primary storage device

SECONDARY STORAGEA storage medium that permanently holds data and information as well as. For example, afloppy disk drive or a hard disk drive is an example of a secondary storage device.

FLOPPY DISKSA floppy disk often called a diskette or simply disk is a removable flat piece of Mylar plastic

packaged in 3.5 inch plastic case. Data and programs are stored on the disks coating by meansof magnetized spots. Floppy disks are slower to access than hard disks and have less storagecapacity, but they are much less expensive. And most importantly, they are portable.

Floppies come in three basic sizes:

8-inch: The first floppy disk design, invented by IBM in the late 1960s and used in theearly 970s as first a read-only format and then as a read-write format. The typicaldesktop/laptop computer does not use the 8-inch floppy disk.

5-inch: The common size for PCs made before 1987 and the predecessor to the 8-inchfloppy disk. This type of floppy is generally capable of storing between 100K and 1.2MB(megabytes) of data. The most common sizes are 360K and 1.2MB.

3-inch:Floppy is something of a misnomer for these disks, as they are encased in a rigidenvelope. Despite their small size, microfloppies have a larger storage capacity than theircousins -- from 400K to 1.4MB of data. The most common sizes for PCs are 720K (double-density) and 1.44MB (high-density). Macintoshes support disks of 400K, 800K, and1.2MB.

HARD DISKSA magnetic disk on which you can store computer data is called Hard Disk. Hard disks holdmore data and are faster than floppy disks. A single hard disk usually consists of severalplatters. Each platter requires two read/write heads, one for each side. All the read/writeheads are attached to a single access arm so that they cannot move independently. Each platterhas the same number oftracks, and a track location that cuts across all platters is called a

cylinder.Hard disks are thin but rigid metal, glass or ceramic platters covered with a substance that

allows data to be held in the form of magnetized spots. Hard Disk stores and providesrelatively quick access to large amounts of data on an electromagnetically charged surface or

set of surfaces. Today's computers typically come with a hard disk that contains several billionbytes (gigabytes) of storage. Computer's main storage media device also called a hard diskdrive or abbreviated as HD orHDD. The hard drive was first introduced on September 13,1956.

FLASH MEMORY

Flash memory is non-volatile computer memory that can be electrically erased andreprogrammed. It is a technology that is primarily used in memory cards, and USB flash drives(thumb drives, handy drive, memory stick, flash stick, and jump drive) for general storage andtransfer of data between computers and other digital products.


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MAGNETIC TAPEMagnetic tape is a non-volatile storage medium consisting of a magnetic coating on a thin

plastic strip. Magnetic tape used for video, audio storage or general purpose digital data storageMagnetic tape is thin plastic tape coated with a substance that can be magnetized spots(representing 1s) or non- magnetized spots (representing 0s). Today magnetic tape is used for

backup and archiving that is for maintaining historical records where there is no need for quickaccess. In computing, magnetic tape was first used to record data and programs in 1951 as partof the UNIVAC 1 system. It was very popular as a storage medium for external memory in the

1950s and 1960s.OPTICAL DISK

An optical disc is an electronic data storage medium that can be written to and read using alow-powered laserbeam. Originally developed in the late 1960s, the first optical disc, created

by James T. Russell, stored data as micron-wide dots of light and dark. A laser read the dots,and the data was converted to an electrical signal, and finally to audio or visual output.An optical disk is a removable disk usually 4.5 inches in diameter and less expensive than one-twentieth of an inch thick, on which data is written and read through the use of laser beamOptical disc storage, is non-volatile and sequential access. The following forms are currently

in common use:[4]

CD, CD-ROM, DVD: Read only storage, used for mass distribution of digitalinformation (music, video, computer programs)

CD-R, DVD-R, DVD+R: Write once storage, used for tertiary and off-line storage CD-RW, DVD-RW, DVD+RW, DVD-RAM: Slow write, fast read storage, used for

tertiary and off-line storageThere are two common types of optical technology. The most widely used type is compact disk(CD) Technology which is used in CD-ROM, WORM, and CD-Recordable. The other typewhich has been steadily gaining in popularity over the fast few years is a hybrid that combinesmagnetic and optical technology. These devices are known as magneto Optical Drive.

CD-ROMCD-ROM Pronouncedsee-dee-rom. Short forCompactDisc-Read-Only Memory, a type ofoptical disk capable of storing large amounts of dataCD-ROM (Compact Disc, read-only-memory) is an adaptation of the CD that is designed tostore computer data in the form of text and graphics, as well as hi-fi stereo sound.CD-ROMs are popularly used to distribute computer software, including games andmultimedia applications CD-ROM discs are read using CD-ROM drives, which are nowalmost universal on personal computers

DVD- ROMDVD (also known as "Digital Versatile Disc" or "Digital Video Disc) is a popular optical discstorage media format. Its main uses are video and data storage.DVD-ROM has data which can only be read and not written,DVD-Rcan be written once and then functions as a

DVD-ROM, and DVD-RA

M orDVD-RW holds data that can be re-written multiple times.

MAGNETO- OPTICAL DRIVE

Magneto Optical Diskcombine some of the best features of both magnetic and opticalrecording technologies. An MO Disk is the capacity of an optical disk but can be written withthe ease of a magnetic disk. MO disk are available today in various size and capacities.Amagneto-optical drive is a kind ofoptical disc drive capable of writing and rewriting data

upon a magneto-optical disc. . The technology was introduced at the end of the 1980s


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OPERATING SYSTEMOperating system is a set of program that lies between application software and the computerhardware. It is the fundamental software that control access to all other software and hardwareresources. ORThose software which boot the computer machine and manages all the hardwareand software resources. Operating system provides an environment between the user andcomputer where desire task/goal can be achieved. Operating System consists of master system

of programs that manage the basic operation of the computer.Operating system perform the following tasks

Co-ordinate processing Manage the use of main memory Allocates use of peripheral devices Check equipment mal function and display error message Manages file stored on disk

TYPES OF OPERATING SYSTEMThere are two types of operating system

1. Single user operating system2. Multi user operating system

SINGLE USER OPERATING SYSTEM

Those operating system which do not provide multi-user environment because of not havingnetworking feature Example DOS.

1. DOS = DISKOPERATING SYSTEMDOS stand for Disk Operating System. DOS is a single user operating system DOS is

primarily use on IBM & IBM compatible microcomputer. DOS uses a character user interface(CUI). It is text user interface operating system. There two version of DOS.1. PC DOS Personal Computer DOS made forIBM Computer2. MS- DOSMicrosoft DOS, developed for 16-bit microcomputers

MULTI USER OPERATING SYSTEM

Those operating system which provide multi-user environment because of having networkingfeature is called multiuse operating system Example Windows, Unix, Linux.

1. WINDOWSWindows is an operating system made by Microsoft Company that lays graphical user

interface shell around the MS-DOS and PC-DOS and extend the Doss Capabilities. Windowsis a multi-user, multitasking operating system. Windows operating system is designed to

support desktop and portable computer. Windows is Graphical User Interface (GUI). Thatenable user to select menu option by choosing picture called icon that correspond the

appropriate processing option. The most widely used version of the Microsoft Windows familyis Windows XP, released on October 25, 2001

Example: Windows 95. Windows xp, windows vista etc

2. UNIXUNIX is a multi-user centralized operating system originally developed in 1969 by a group ofAT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and DouglasMcElroy Unix was designed to be portable, multi-tasking and multi-user in a time-sharingconfiguration. UNIX is an operating system for multi-user and with built-in networkingcapability the ability to run on all kinds of computer from micro to mini to mainframecomputer. The primary user of UNIX is large corporation and Banks etc


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3. LINUXLINUX is a full 32-bit, multi-tasking operating system that supports multiple user and multiple

processors. LI NUX can run on nearly any compute and can support almost any type ofapplication. Linux uses a command line interface but windows based GUI environment calledshell are available. Linux kernel and other components are free and open source software

APPLICATION SOFTWAREPrograms that help people accomplish specific tasks are referred to as application softwareThese programs, called application software are designed and created to perform specific

personal, business, or scientific processing tasks, such as word processing, tax planning,computer games, spreadsheets, data base management software, Graphics multimedia,

presentation application, utilities and communication software.

WORD PROCESSING SOFTWARE

Word processing software provides an extensive set of tools for working with text it is used tocreate all kinds of documents, from the simplest notes to complete books containing hundredsof pages, every day, millions of people use word processing software to create and edit memos,

letter brochures, resumes reports and many other kinds of documents. Commonly used wordprocessor MS-WORD.SPREADSHEET:

A spreadsheet is a software tool for entering, calculating, manipulating and analyzingset of numbers. Spreadsheets have a wide range uses from family budgets to corporate profitand loss statements.You can setup a spreadsheet to show information in any number of ways, such as thetraditional row-and column format or a stick report format with heading and charts.Commonly in used spreadsheet Lotus 123 and MS-Excel.

DATABASE MANAGEMENT SYSTEMA database is a repository for collections of related data or facts.

A database management system (DBMS) is a software tool that lets users add, view, and workwith the data in a database.Large databases and DBMS are commonly used by companies, but many productivityapplications are built around database concepts Commonly used Database management systemis MS-ACCESS, ORACLE, SQL Etc. The main working of Database is Creating DatabaseTables, Viewing Records, Sorting Records, Querying a Database, Generating Reports

PRESENTATION PROGRAM

Presentation programs are used to create slidessingle-screen images that contain text,graphics, charts, and more. A collection of slides is called a presentation.A presentation program lets you create a set of slides and show (present) them to an audience.Presentation programs provide many of the same editing and formatting tools found in word

processors and other common applications commonly presentation program is MS - POWERPOINT.


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HIERARCHY OF LANGUAGES:Languages are types of application software and consist on three types as mentioned

bellow.MACHINE LANGUAGE:This is the language, which can be directly understood by the computer. Earlier programmers

wrote their programs in machine language. Any information or instruction in this language isto be represented in terms of 0s and 1s. The digits 0 standing for the absence of an electric

pulse and 1 for the present of an electric pulse. As a computer a is able to recognize thepresence or absence of an electric pulse, it is able to understand the machine language. Eachinstruction in the machine language was usually broken into two parts which are known asoperation code (p-code) and the operand.The operation code specified the operation to be done, and the operand gave the location oraddress of the data to be processed. If there is only one address of a memory location in aninstruction then such an instruction is called a single address instruction. If there are twoaddresses of memory locations following the operations code then this instruction is called astwo address instruction.

ASSEMBLY LANGUAGE:Here the sequence of zeros and ones that serve at operation codes in machine language arereplaced by mnemonics (memory aid or alphabetic codes). The operands are symbolizedtemporarily in later choosing by the program.Each assembly language instructions may have three parts, not all of which need occur in agiven instructions. These are the first part is the label or tag. These are the programmer definedsymbols that give the address of the instructions. Then follow the OPS code and the operand aswith the machine language instruction.LOW LEVEL LANGUAGE:Low level language is machine oriented language. Which require extensive knowledge ofcomputer circuitry? For Example the number of bits required to represent one instruction isdetermined by the word length of a location in central memory. Normally, an instruction oflow level language consist of two parts, which are known as a function part (i.e. do someactivity) and an address part (i.e. using the contents of an address location). The number of bitsin the function part will determine. The number of possible unique instruction a computer canobey. The number of bits for the address part must complete the overall size (word) of thecentral memory.To prevent insanity on the part of the people who program at this low level, differentmnemonics are used to represent the different binary patterns for each machine codesinstruction. When using these machine mnemonics instead the pure machine code, this methodof programming is called Assembly language programming. Therefore, the low level languagefurther divided into machine language and Assembly language.HIGH LEVEL LANGUAGE:Today one normally writes computer programs almost in English computer languages such

FORTRA N, COBOL, BASIC and other many, These are called High Level language todistinguish them from the low level languages that is machine and assembly languages. Theyare also called compiler languages, since the each require a special program called a compilerwhich translates programs written in that language into machine language. The original

program written in high level language is called sources program and its translation in machinelanguage is called object program.High level language shares three important advantages.

Simplification

Standardization

Diagnostic error decision


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Introduction to Computer ScienceSince the terminology in high level language is almost the languages can be easily read andunderstood. Infect most people can write simple programs after few days study. The high levellanguage has been standardized. Thus programs written in FORTRAN can be understood by

people throughout the world. In particular these languages are machine independent. In so faras a high level language program can be accepted by any computer which has a compiler forthat language. Each high level language has its own syntax or set of rules that govern the

writing of the statements in the languages. Hence, before a program is translated and executed,the compiler checks the each statement in the program for syntax errors. All such errors areoutput and translation is not begun by the complier until all the errors have been correct by the

programmer.FORTRAN: (Formula Translation):

FORTRAN developed in 1957 was one of the first high level languages. As its name suggests,it syntax is similar to that of mathematically formulas, and scientific application, FORTRANS

primary advantages or its excellent mathematical capability and its compactness. Further moreits compiler needs a relatively mall amount of memory and this can be used in the smaller

computer.COBOL: (Common Business Oriented Language):

COBOL was developed in the late 1959 as a universal for business applications. There are

three advantages of COBOL as follow. It closely resembles English, so that programs writtenin COBOL can be followed by nonprogrammers.It can easily manipulate alphanumeric data example it can easily convert 0123456 to $ 123456in COBOL, while it is difficult to do so in FORTRAN. It can handle I/O operations. Thus it is

particularly useful for processing large data files. A disadvantage of COBOL is that it compilerrequires a large amount of memory and so the use of COBOL is limited to medium and largecomputer.

BASIC: (Beginners All Purposes Symbolic Instructions Code):Basic was developed in the late 1965 at DARMOUTH COLLEGE mainly to make it easier forstudent to use the computer for simple problem. It is similar to FORTRAN With slightly moreEnglish like qualities and with more ease and handling input and output data. An importantadvantage of BASIC as it is an interactive language .The programmer can directly interact with

the computer via a keyboard terminal quickly writing, correctly and obtaining partially resultsof its program. Finally we not that basic is the language normally use with micro computers.


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DATA COMMUNICATION

DATA COMMUNICATION

Data Communication is the transfer of data from on device to another device via some form oftransmission medium

NETWORK

Network is a group of interconnected computer system. Sharing services and interacting bymeans of shared communication link is called networkTYPES OF NETWORK

LAN =Local Area NetworkMAN = Metropolitan Area NetworkWAN= Wide Area Network

1. LOCAL AREA NETWORK(LAN)A Local Area Network (LA N) is a group of computer and network communication device

interconnected within a geographically limited Area Such as Building or Campus or betweennear By building ORA LA N is a data communication system within building, plan, campus or between near by

building. A LAN tends to use only one type of transmission medium (Cabling)

2. METROPOLITAN AREA NETWORK(MAN)A Metropolitan Area Network (MAN) is a group of computer and network communicationdevice interconnected within a geographically limited Area of City. A Metropolitan Area

Network can interconnect with local area network that uses different hardware andtransmission medium.A MAN is a data communication system covering an area the size of town or city.

3. WIDE AREA NETWORK(WAN)A Wide Area Network (WA N) interconnects with LANS OR MANS.A Wide Area Network

(WAN) may be located entirely within a state or country it may be interconnected around theworld. A WAN is data communication system spanning states, countries or the whole world

Network Topologies for LANsA network's topology is the layout of the cables and devices that connect the nodes. The fourmost common network topologies are:Bus. Each node is connected in series along a single conduit.Star. All nodes are connected to a central hub.Ring. Nodes are connected in a circular chain, with the conduit beginning and ending at thesame computer.Mesh. Each node has a separate connection to every other node.

MODEMThe word MODEM stands forMOdulator, DEModulator. A modem is a device that convertsdigital signal to Analog signal and vice versa.

PROTOCOL

A protocol is a set of rules that govern how computers talk to each other.

TCP/IP=TRANSMISSION CONTROL PROTOCOL / INTERNET PROTOCOL


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Introduction to Computer ScienceTCP/ IP Stand for Transmission Control Protocol / Internet Protocol. TCP / IP is a widelyused popular protocol. DARPA (Defense Advanced Research Project Agency) was an agencywho developed the TCP/IP suite protocol and implemented in internet work called ARPANET(Advance Research Project Agency Network). By TCP/IP different computer system canreliable to exchange data on an interconnected network. It also provides a consistent set ofapplication programming Interfaces to support application development. This means that

software programs can use TCP/IP to exchange data. An example is web server and webbrowser

HTTP= HYPER TEXT TRANSFER PROTOCOLHTTP stands HyperText TransferProtocol. HTTP is the set of rules for exchanging files(Text, graphic image, sound, video and other multimedia files) on the World Wide Web(www). HyperText TransferProtocol is the main protocol that is used to access the data onthe World Wide Web. HTTP transfer data in the form of plane text, hypertext, sound, video&so on. How it is called HyperText TransferProtocol because it use in hypertext environmentwhere there are rapid jumps from one document to another

INTERNETThe Internet was created by the Advanced Research Projects Agency (ARPA) and the U.S.

Department of Defense for scientific and military communications.It was conceived by the Advanced Research Projects Agency (ARPA) of the U.S. government

in 1969 and was first known as the ARPANETThe Internet, sometimes called simply "the Net," is a worldwide system of computer networks- a network of networks in which users at any one computer can, if they have permission, getinformation from any other computer (and sometimes talk directly to users at other computers)The Internet uses high-speed data lines, called backbones, to carry data. Smaller networksconnect to the backbone, enabling any user on any network to exchange data with any otheruser

WORLD WIDE WEB (WWW)The World Wide Web is a part of the Internet, which supports hypertext documents, allowingusers to view and navigate different types of data.A Web page is a document encoded with hypertext markup language (HTML) tags.HTML allows designers to link content together via hyperlinks.

Every Web page has an address, a Uniform Resource Locator (URL)ELECTRONIC MAIL (E-MAIL)

Electronic mail (e-mail) is the most popular reason people use the Internet.To create, send, and receive e-mail messages, you need an e-mail program and an account

on an Internet mail server with a domain name.To use e-mail, a user must have an e-mail address, which you create by adding your user name

to the

E-mail server's domain name, as [email protected] Browsers:Web Browsers are applications used to navigate and view documents on the Web. There aretwo browsers commonly used in the world. Netscape Navigator and Microsoft Internet

booklet of computer

Documents