Chapter 1 Basic Computer Skills PDF

CHAPTER1 BASIC COMPUTER SKILLS INTRODUCTION WHAT IS A COMPUTER? The word “Computer” is derived from the word „compute". It means „to calculate" We apply mathematical operations like addition, subtraction, multiplication, division, etc. and many other formulae for calculations...

CHAPTER1 BASIC COMPUTER SKILLS INTRODUCTION WHAT IS A COMPUTER? The word “Computer” is derived from the word „compute". It means „to calculate" We apply mathematical operations like addition, subtraction, multiplication, division, etc. and many other formulae for calculations So man explored with the idea to develop a machine, which can perform this type of arithmetic calculation faster, and with full accuracy DEFINITION OF A COMPUTER “A computer is an electronic device, which can be programmed to perform high speed mathematical or logical operations to put it simply. CHARACTERISTICS OF A COMPUTER LET US IDENTIFY THE MAJOR CHARACTERISTICS OF A COMPUTER 1. SPEED It takes only few seconds for You will be surprised to know that calculations that we take hours to computer can perform several million complete of instructions and even more per second Therefore, we determine the speed of computer in terms of microsecond or nano-second 2. ACCURACY Suppose someone calculates faster but commits a lot of errors in computing, then such a result is useless But a computer can give up to 100 decimal places within a fraction of second and that too accurately Hence, in addition to speed, the computer provides very high level of accuracy or correctness in computing 3. DILIGENCE If millions of calculations Due to this capability, it is A computer is free from are to be performed, a better than human being tiredness, lack of computer will perform in routine and repetitive concentration, fatigue, etc every calculation with the types of work same accuracy 4. VERSATILITY IT MEANS THE CAPACITY TO YOU MAY USE YOUR COMPUTER PERFORM COMPLETELY TO PREPARE PAYROLL SLIPS DIFFERENT TYPE OF WORK NEXT MOMENT YOU MAY USE IT FOR INVENTORY MANAGEMENT OR TO PREPARE ELECTRICITY BILLS OR PREPARE ACCOUNTS, ETC 5. MULTI- A human being cannot do more than one TASKING task at the same time without losing his concentration or with his full efficiency But for a computer, it is a normal thing to do many tasks simultaneously without compromising in its efficiency This is known as multi-tasking 6. POWER OF MEMORY OR STORAGE Computer has the power of storing huge amount of information or data Information can be stored and recalled if you require it, for any number of years You can also store data in secondary storage devices such as floppies and CDs, which can be kept outside your computer and can be carried to other computers 7. NO IQ Believe me! Computer is a dumb machine, and it cannot do any work without instructions from the user It is considered as a faithful idiot that can only perform the instructions given to it at a tremendous speed and with high accuracy without understanding of the work being done by it 8. NO FEELINGS Computers do not have feelings or emotion, taste, knowledge and experience Thus, a computer does not get tired even after doing long hours of work It does not distinguish between users and different kinds of work being done by it HISTORY OF COMPUTERS This process of counting of large numbers generated various systems of numeration like Babylonian system of numeration, Greek system of numeration, Roman system of numeration and Indian system of numeration Out of these the Indian system of numeration has been accepted universally It is the basis of modern decimal system of numeration CALCULATING MACHINES It took generations for early man to build mechanical devices for counting large numbers The first calculating device called ABACUS, was developed by the Egyptian and Chinese people The word ABACUS means calculating board NAPIER’S BONES English mathematician John Napier built a The device was known as mechanical device for the Napier"s bones purpose of multiplication in 1617 AD SLIDE RULE ENGLISH MATHEMATICIAN THIS MACHINE COULD PERFORM EDMUND GUNTER DEVELOPED OPERATIONS LIKE ADDITION, THE SLIDE RULE SUBTRACTION, MULTIPLICATION, AND DIVISION IT WAS WIDELY USED IN EUROPE IN 16TH CENTURY PASCAL’S ADDING AND SUBTRACTION MACHINE You might have heard the name of Blaise Pascal He developed a machine at the age of 19 that could add and subtract The machine consisted of wheels, gears and cylinders LEIBNIZ’S MULTIPLICATION AND DIVIDING MACHINE The German philosopher and mathematician Gottfried Leibniz built around 1673 a mechanical device that could both multiply and divide BABBAGE’S ANALYTICAL ENGINE IT WAS IN THE YEAR 1823 THAT A LATER HE DEVELOPED A GENERAL FAMOUS ENGLISH MAN CHARLES PURPOSE CALCULATING MACHINE BABBAGE BUILT A MECHANICAL CALLED ANALYTICAL ENGINE MACHINE TO DO COMPLEX MATHEMATICAL CALCULATIONS YOU SHOULD KNOW THAT CHARLES BABBAGE IS CALLED THE FATHER OF COMPUTERS MECHANICAL AND ELECTRICAL CALCULATOR In the beginning of 19th century, the mechanical calculator was developed to perform all sorts of mathematical calculations, and it was widely used till Later the routine part of mechanical calculator was replaced by electric motor It was called the electrical calculator MODERN ELECTRONIC CALCULATOR The electronic calculator used in 1960s was run with electron tubes, which was quite bulky Later it was replaced with transistors and as a result the size of calculators became too small The modern electronic calculators can compute all kinds of mathematical computations and mathematical functions COMPUTER GENERATIONS You know that the evolution of computer started from 16th century and resulted in the form that we see today The present day computer, however, has also undergone rapid changes during the last fifty years This period, during which the evolution of computer took place, can be divided into five distinct phases known as Generations of Computers FIRST GENERATION These computers were large in size and writing programs on them was difficult COMPUTERS Some of the important computers of this generation were: ENIAC: It was the first electronic computer built in 1946 at University of Pennsylvania, USA by John Eckert and John Mauchly The ENIAC was 30 x 50 feet long, weighed 30 tons, contained 18,000 vacuum tubes, 70,000 resistors, 10,000 capacitors and required 150 kilowatts of electricity SECOND GENERATION COMPUTERS Around 1959 an electronic device It is in the second generation that the called Transistor replaced the bulky concept of Central Processing Unit , vacuum tubes in the first-generation memory, programming language and computer input and output units were developed Some of the computers of the Second Generation were IBM 1920 : Its size was small as compared to First Generation computers and mostly used for scientific purpose THIRD GENERATION COMPUTERS The third-generation computers were introduced in Some of the computers developed during this period were IBM-360, ICL-1900, IBM-370, and VAX The features of computers belonging to this generation were: (Used tiny Ics, Relatively very small in size , Made use of operating system, High processing speed, More reliable, Power efficient and high speed, Use of high-level languages, Large memory, and Low cost. FOURTH GENERATION COMPUTERS The present day computers that you see today are the fourth-generation computers that started around It uses Large Scale Integrated Circuits built on a single silicon chip called microprocessors Due to the development of microprocessor it is possible to place computer's central processing unit on a single chip FIFTH GENERATION COMPUTERS The computers, which can think and take decisions like human beings have been characterized as Fifth generation computers and are also referred as thinking machines The concept of Artificial Intelligence has been introduced to allow the computer to take its own decision A lot of research and development work is going on in this area in United States and Japan, but it will take some time before such machines are produced for use by the industry CLASSIFICATION OF COMPUTERS Differences in certain computer characteristics have led to the development of major computer classifications based on the type of electronic signal and memory size Micro Computers:- Microcomputer is at the lowest end of the computer range in terms of speed and storage capacity The first microcomputers were built of 8-bit microprocessor chips Supercomputer is mainly used for weather forecasting, biomedical research, remote sensing, aircraft design and other areas of science and technology Examples of supercomputers are CRAY YMP, CRAY2, NEC SX- 3, CRAY XMP and PARAM from India APPLICATIONS OF COMPUTERS IN VARIOUS FIELDS We find their applications in almost every sphere of life-particularly in fields where computations are required to be done at a very fast speed and where data is so complicated that the human brain finds it difficult to cope up with As you must be aware, computer now-adays are being used almost in every department to do the work at a greater speed and accuracy Some of the prominent areas of computer applications are in Tourism, Banks, Industries, Transportation, Education, Entertainment and so on. ENTIFY THE MODELS OF COMPUTERS Hard drive for storage These computers do not have keywords but relay on touch screen technology for user input CONCEPTS OF HARDWARE AND SOFTWARE Computer hardware is the collection of physical elements that comprise computer system Computer hardware refers to the physical parts or components of computer such as monitor, keyboard, hard disk, mouse, etc Computer software or just software, is a collection of computer programs and related data that provides the instructions for telling a computer what to do and how to do it PHYSICAL COMPONENTS OF COMPUTER Mother Board: It is also called as system board / panel board / main board Processor Chip: It is also called as Central Processing MEMORY Memory: It is a storage device used to store information in computers The semiconductor memory is organized into memory cells or bistable flip-flops, each storing one binary bit The memory cells are grouped into words of fix word length, for example 1, 2, 4, 8, 16, 32, 64 or 128 bit Each word can be accessed by a binary address of N bit, making it possible to store 2 raised by N words in the memory What are bits, bytes, and other units of measure for digital information? So in computer jargon, the following memory units are used: There are different types of memories in computers:- Registers: Small memory, internal to processor, where actual processing is done MEMORY Other memory devices can access the storage data only in a predetermined order, because of mechanical design limitations SECONDARY MEMORY Both hard disk and hard disk drive comes in a single unit, it is permanently fixed in a system unit A Hard Disk Drive is device for storing and retrieving digital information, primarily computer data A typical HDD design consists of a spindle that holds flat circular disks, also called platters, which hold the recorded data The platters are made from a nonmagnetic material, usually aluminium alloy and are coated with a shallow layer of magnetic material typically 10-20 nm in depth, with an outer layer of carbon for protection FLOPPY DISK DRIVE A floppy disk, or diskette, is a disk storage medium composed of a FDD : Floppy disk drive is a It has a control circuit which disk of thin and flexible magnetic mechanism which drives FD to transfers data between FD and storage, sealed in a rectangular rotate for read / write operations computer plastic carrier lined with fabric that removes dust particles COMPACT DISK DRIVE : The CD-Drive is a mechanism used to read / write digital information on a CD CD-Drives are available in different forms, CD drive is an optical disc drive that uses LASER light or Electromagnetic waves of suitable wavelength as part of the process of reading or writing data to or from CD CD drives are commonly both readers and recorders, also called burners or writers Compact Disc , Digital Versatile Disc and Blue-ray Disc are common types of A recorder encodes data onto a recordable CD-R, DVD-R, DVD+R For rewritable CD-RW, DVD-RW, DVD+RW, DVD- RAM, or BD-RE media, the laser is used to melt a crystalline metal alloy in the recording layer of the disc COMPACT DISK DRIVE CD data is stored as a series of tiny indentations Instead, nonreturn-to-zero encoding is used: a known as "pits", encoded in a spiral track moulded change from pit to land or land to pit indicates a into the top of the polycarbonate layer one, while no change indicates a series of zeros SWITCHED MODE POWER SUPPLY SMPS: It refers to Switched Mode Power Supply Ports:- Ports are the sockets available on the system box Serial Port :- It is a Serial Communication physical interface through which information transfers in or out one bit at a time Parallel Port It is a type of interface used to connect a printer to the computer USB :- It combines all the advantages of multi- platform serials ports VGA / SVGA / AGP SOUND CARD It is an expansion card that records and plays back sound by translating the analog signal from a microphone into a digitized form that the computer can store and process and then translating back the modified data into analog signals or sound Network Card;- If we want to connect our computer to another computer we will need a Network Interface Card MODEM ;- In order to go online and surf the web or check E-mail, we need a modem to connect to an internet service provider INPUT DEVICES Input Devices: The input devices are used for transferring / entering user command or data or choice to the computer Input unit captures or reads data / information and converts these data into form that computer understands and transfers these data to memory unit for execution Eg: Keyboard, Mouse, Scanner, Joystick, Floppy, CD, DVD etc KEYBOARD The keys on a keyboard is almost similar to typewriter keys with some additional keys such as programmed function keys, programmable keys, cursor control keys and numeric keys Standard"full-travel"alphanumeric keyboards have keys that are on three-quarter inch centers , and have a key travel of at least 0.150 inches Windows standard keyboards has 104-keys, which includes alphabetic characters, punctuation symbols, numbers and a variety of Function keys MOUSE The mouse sometimes features other elements, such as "wheels", which allow the user to perform various system-dependent operations, or extra buttons or features that can add more control or dimensional input The mouse's motion typically translates into the motion of a pointer on a display, which allows for fine control of a graphical user interface Optical mice make use of one or more Light Emitting Diodes and an imaging array of photodiodes to detect movement relative to the underlying surface, rather than internal moving parts as does a mechanical mouse SCANNER Scanner is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image Common examples found in offices are variations of the desktop scanner where the document is placed on a glass window for scanning Scanner consists of two components, the first one to illuminate the object so that the optical image can be captured and the other to convert the optical image into digital format for storage by computer JOYSTICK A joystick is an interactive input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer OUTPUT Output Devices: An output device is a computer hardware DEVICES equipment used to communicate the results of data processing carried out by computer by converting the electronically generated information into human-readable form Output devices produces information in the form of printouts, display on monitor etc., Output devices converts processeddataintoformthattheuserunderstands instantly Eg: Monitor, Printer, Plotter, Speakers, Headphones, Projectors etc MONITOR The monitor comprises the display device, circuitry, and an enclosure The display device in modern monitors is typically a Thin Film Transistor or Liquid Crystal Display thin panel, while older monitors use a Cathode Ray Tube about as deep as the screen size The first computer monitors used Cathode Ray Tubes TFT-LCD Thin film transistor liquid crystal TFT LCD is one type of Active display is a variant of LCD which matrix LCD, though all LCD- uses thin-film transistor screens are based on matrix technologytoimproveimagequality addressing LED AND OLED Organic light-emitting diode monitors provide higher contrast and better viewing angles than LCDs, and are predicted to replace PRINTER A printer is a peripherals which produces the hard copy output of a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a USB cable to a computer which serves as a document source There are two types of printers PLOTTER Plotter is an output device similar to printer, which produce hard copy output of graphs, maps, charts, etc., on any sort of paper The plotter is very convenient and invaluable tool in business graphics applications for printing on very large size papers like Film posters, AutoCAD building drawings etc OPERATING SYSTEM An Operating System is a program that controls the overall activity of your computer It manages the various files in your computer It allows the computer hardware to interact with your computer software