Book 6 Author Er. Shankar N. Adhikary Oasis Radiant Computer Science Oasis Publication (P) Ltd. Anamnagar, Kathmandu Phone :0977-01-4313205
Oasis Radiant Computer Science, Book 6 2 Oasis Radiant Computer Science Class 6 Author Er. Shankar N. Adhikary Layout Design: Zeeta Computer Service Pvt. Ltd. Ghantaghar, Kathmandu Publisher: Oasis Publication (P) Ltd. Anamnagar, Kathmandu Nepal Tel: 977-01-4313205 www.oasispublication.com.np Printed in Nepal © Publisher First edition : 2019 Second edition : 2020 Third revised edition : 2022 This book belongs to... Name : Mr./Miss ................................................................... Class : .................. Section. .................. Roll No.................. School : ................................................................................. ..............................................................................................
3 Oasis Radiant Computer Science, Book 6 CONTENTS Unit Chapter Page No. 1 Introduction to Computer 5 2 Computer Hardware 15 3 Input and Output Devices 20 4 Storage Devices 28 5 Computer Software 35 6 Operating System 40 7 Computer Graphics Photoshop 54 8 Microsoft Word 69 9 Microsoft Excel 112 10 Microsort PowerPoint 140 11 ITC and Its Uses 163 12 Introduction to the Internet 169 13 Multimedia 177 14. Programming Tools and Techniques 182
Acknowledgement We are in the 21st century. This is the age of Information and Communication Technology (ICT). ICT has become an integral part of our daily life. It facilities business people, academicians, students, and professionals in the banking and other sectors. Computer education has become a fundamental right of children. Today’s children need the knowledge of computer, from basic to advanced level, to cope with the changes unfolding now and coming in the future. The Curriculum Development Centre (CDC) of Nepal government has prescribed the syllabi and course outlines for computer education from primary to higher secondary level. Students are deprived of quality computer education due to the lack of quality course books and limited access to the computer system in schools. To address this issue, I have developed a complete series of computer books under the banner “Oasis Radiant Computer Science” from grade I to grade XII. I have devoted a lot of time in the research and development of this book. It provides a comprehensive and balanced coverage of the CDC syllabus. All this has been possible thanks to the comprehensive support I received from my family members, colleagues, students and teachers. I would like to acknowledge all who have directly or indirectly encouraged me to prepare this book for their contribution. Specially, my thanks go to the students and teachers of different schools for their regular interactions with me and inspirations they gave me to prepare this book. I am grateful to my parents Tek Nath and Chisa Maya Adhikary, family members Lachhima Adhikary, Jagan Adhikary, Sarashwati Adhikary and lovely kids Samridhi, Sampada, Prasamsha, Ballavi, Ragavi, Suyash and Suyasha Adhikary for their valuable contributions from their place as I prepared this book. OASIS PUBLICATION family deserve kudos for their innovative help in preparing and publishing this book. Finally, all the suggestions and comments are acknowledged. Thanking all, Er. Shankar N Adhikary, Tarkeshwor, Kathmandu
Introduction to Computer 1 Chapter 8 Capacities of computer 8 Characteristics of computer 8 Application areas of computer 8 Limitations of computer
Oasis Radiant Computer Science, Book 6 6 This is the age of electronics. Almost all fields of life depend on the electronic system. Housewives, officers, bankers, businessmen, teachers and students are all directly or indirectly dealing with electronic devices. Computer is the leading electronic device, which is very versatile. It is used in different fields to make tasks easier. It is also called the data processor because it accepts the data and processes them to give meaningful information. Computer is an electronic device which can perform computation as well as logical action at a very high speed. We can set the programme in the computer that leads the system to work automatically by using a sequence of arithmetic and logical operations. It can process both numerical and non-numerical data arithmetically and logically and save the information for the future. As you know from the previous classes, computer consists of three sections: input, processing with storage and output. Input devices are used to capture input from the user. CPU (Central Processing Unit) is used to process the data arithmetically and logically. Output devices are used to give output to the user. Components of Computer System Computer system is the collective use of computer hardware structures and software applications. Computer system consists of the standard hardware structure to support the operational activities of the software. Basically computer architecture has the following processing units: Introduction to 1 Computer Chapter
7 Oasis Radiant Computer Science, Book 6 1. Input/ Output (I/O) Unit, 2. Central Processing Unit (CPU), and 3. Memory Unit. The I/O unit consists of the Input Unit and the Output Unit. CPU performs calculations and processing on the input data to generate the output. The memory unit is used to store the data, the instructions and the output information. Following figure illustrates the typical interaction among the different components of the computer. Input and Output Unit • User interacts with the computer using the input and output (I/O Unit) of computer. The Input Unit accepts data from the user and the Output Unit provides the processed data i.e. the information to the user. The Output Unit converts the data that it accepts from the user, into a form that is understandable by the computer. Similarly, the Output Unit provides the output in a form that is understandable by the user. The input is provided to the computer using input devices like keyboard, trackball and mouse. Some of the commonly used output devices are monitor and printer. • Central Processing Unit, or CPU, controls, coordinates and supervises the operations of the computer. It is responsible for the processing of input data. CPU consists of Arithmetic Logic Unit (ALU) and Control Unit (CU).
Oasis Radiant Computer Science, Book 6 8 • ALU performs all the arithmetic and logic operations on the input data. • CU controls the overall operations of the computer i.e. it checks the sequence of execution of instructions, and, controls and coordinates the overall functioning of the units of computer. • Additionally, CPU also has a set of registers for temporary storage of data, instructions, addresses and intermediate results of calculation. Memory Unit Stores the data, instructions, intermediate results and output, temporarily, during the processing of data. This memory is also called the main memory or primary memory of the computer. The input data that is to be processed is brought into the main memory before processing. The instructions required for processing of data and any intermediate results are also stored in the main memory. The output is stored in memory before being transferred to the output device. CPU can work with the information stored in the main memory. Another kind of storage unit is also referred to as the secondary memory of the computer. The data, the programmes and the output are stored permanently in the storage unit of the computer. Magnetic disks, optical disks and magnetic tapes are examples of secondary memory. Characteristics of Computer High Speed: Computers have very high speed. They can execute millions (1,000,000) of instructions and even more per second. They can perform tasks in a fraction of a second. Their speed of performance is measured in Milli, Micro, Nano and Pico seconds. Unit of time Part of second Milliseconds (ms) Microseconds (µs) Nanoseconds(ns) Picoseconds(ps) One thousandth 1/1,000 One millionth 1/1,000,000 One billionth 1/1,000,000,000 One trillionth 1/1,000,000,000,000
9 Oasis Radiant Computer Science, Book 6 Accuracy: Computers are very accurate devices. If the logic and the input are correct it never makes mistakes. The errors in computer are due to users and inaccurate data. If input is wrong, output also will be wrong. This concept is called GIGO (Garbage in Garbage Out). Automatic: Computers are software guided system so they are automatic devices. They perform the task without any intervention of user. They work automatically after providing the data and instruction. Versatile: The capability to perform the task in multiple areas is called versatility. Computers can be used for various purposes such as for home, business, weather forecasting, teaching, railways, banking, medicine, etc. In our daily life also we can use the computer for typing, watching movie, designing and browsing the internet. Memory: Computer system has become popular due to its memory system. It can store data which the user wants to retrieve for future use. Different types of secondary storage devices are Hard Disk, Pen Drives, Memory Cards, CDs and DVDs, Zip drives etc. Application Fields of Computer Computers are used in a wide range of areas such as banking, education, hospital, industries, research, data processing, science and engineering, offices, railways, advertisement, communication, library, simulation, weather forecasting, communication, etc. 1. Banking and financial companies Computers are used in banks and financial companies for electronic money transfer, balance sheet, etc. There are different systems used in banks such as ATM (Automated Teller Machine), EFTS
Oasis Radiant Computer Science, Book 6 10 (Electronic Fund Transfer System), etc. 2. Education Computer is used as the teaching-learning tool in schools and colleges. Students can use DVDs and internet for collecting and processing educational materials. They can attend the online classes and use the computer for preparation of their project work. 3. Industries Computers are used in the industrial field to support the manufacturing process. New concepts like CAD (Computer Aided Design), CAM (Computer Aided Manufacturing) and CID (Computer Integrated Design), etc. are being used in the industrial sector. 4. Research Computer is used in research in fields such as account, database, graphics, mathematics, etc. Researchers can collect data using online system and process the data with statistical tools. 5. Hospitals Computers are used in hospitals for record keeping. They are used for the billing system. Different types of medical equipment use computer to collect and process the data. 6. Science and engineering Computer is a powerful tool for every branch of engineering: civil, electrical, computer, aeronautic, ceramics, chemical, leather technology, etc. We can use it to design the electric circuit, mother board, building models and machine models.
11 Oasis Radiant Computer Science, Book 6 7. Offices Computers are used in offices, small or large. They are used for preparing reports, storing records, deleting records, updating records, etc. Most offices use word processing package, spreadsheet package, graphics package, presentation package and database package, etc. to support their daily work. 8. Advertisement Computers are used in the field of advertisement. We can see TV advertisement, film animation and paper advertisement which are designed by using computer. 9. Communications E-mail, e-fax, internet, etc are computer-based communications. We can send email and use the internet system for communication. 10. Library Computer software is used for library management. It is used for keeping, borrowing, recording and updating books. Some libraries provide online access and educational DVDs to the user for collecting educational materials. Key Points • A computer is an electronic device, which can perform computation as well as logical action at a very high speed. • The main part of the computer is the Central Processing Unit (CPU) without which nothing can be done on computer. • Computer can perform millions (1,000,000) of instructions in fractions of a second. • The degree of accuracy of computer is very high and every calculation is performed with the same accuracy. • Computer can be used as personal computers, for home uses, for business, weather forecasting, teaching, railways, banking, medicine etc.
Oasis Radiant Computer Science, Book 6 12 Exercise 1. Answer the following questions: a. What is a computer? Write any four capabilities of computer. b. What are the limitations of computer? c. What are the features of computer? Explain any four. d. Why is computer called a versatile machine? e. Write briefly about any four application areas of computer. f. What is animation? • Versatile means the capacity to perform completely different types of work. • Computer systems are used in a variety of areas including education and training, information processing, entertainment, virtual reality and combination of these areas. • The moving graphics image is called animation. • Computers are also used in film making. • Animation system is used to prepare cartoons and documentary. • Computer system is the collective use of computer hardware structures and software applications. Computer system consists of the standard hardware structure to support the operational activities of the software. • User interacts with the computer using the input and output (I/O Unit) of computer. The Input Unit accepts data from the user and the Output Unit provides the processed data i.e. the information to the user. • Central Processing Unit, CPU, controls, coordinates and supervises the operations of the computer. It is responsible for processing of the input data. CPU consists of Arithmetic Logic Unit (ALU) and Control Unit (CU). • Memory Unit stores the data, instructions, intermediate results and output, temporarily, during the processing of data.
13 Oasis Radiant Computer Science, Book 6 2. Fill in the blanks: a. A computer is an …………..device. b. Computer is a …………machine designed to automatically carry out a sequence of arithmetic and logical calculations. c. Computer can process data at a very ………speed. d. Computer is a ………..because it can be used everywhere. e. Computer can perform task in ................ of seconds. f. The movement of graphics image is called ……….. 3. State whether the following statements are True or False. a. CPU is the main processing part of the computer. b. CPU consists of three sections they are input, process and versatile. c. Computer is slower than other computing devices. d. Computer can store data in Hard Disk. e. The degree of accuracy of computer is very high. f. Storage devices are used for data storing. g. We can also attend an online exam with the help of computer. h. Computer gets tired very fast. 4. Write short notes on: a. Accuracy b. Versatile c. Animation 5. Project work a. Collect some pictures of storage devices and paste them on a chart paper. b. Visit some organisations and write some paragraphs about the use of computer there.
Oasis Radiant Computer Science, Book 6 14 Hospital: School: Business House: Furniture Shop:
15 Oasis Radiant Computer Science, Book 6 Computer Hardware 2 Chapter 8 Input and output hardware 8 The storage hardware 8 The system and utility software 8 Applications software
Oasis Radiant Computer Science, Book 6 16 Hardware A computer system is a collection of different physical components. These components are called computer hardware. We can define computer hardware as the components which we can touch and feel. Without hardware, software cannot work. Computer hardware is a body structure of computer and software is the life of the computer. According to the uses and processing capabilities of the computer, we have different types of computer hardware. These are input hardware, processing hardware and output hardware. Computer Hardware 2 Chapter
17 Oasis Radiant Computer Science, Book 6 Input Hardware All the input devices like keyboard, scanner, mouse, etc. are called the input hardware. These are essential to give data and instruction to the computer. Some input hardware are used to capture the text and number data; some are used to capture audio and video data. Without input hardware, user cannot give the commands and data to the computer. Output Hardware Devices connected to the output section of the computer are output hardware. These are the parts of computer used to communicate the results to the outside world. There are different types of output hardware like monitor, printer, speaker, etc. Computer system has two types of output. They are soft output and hard output. Display type hardware like monitor gives soft output and printer type hardware gives hard output.
Oasis Radiant Computer Science, Book 6 18 Storage Hardware Hardware that holds and stores data and instructions for further processing are storage hardware. They store the intermediate and final results before they are sent to the output devices. Various storage devices of a computer system are divided into two categories: primary and secondary. Primary storage devices are internal memory of computer like the RAM, ROM, etc. and secondary storage devices of the computer are external memory like Hard Disk, DVDs, Pen drive, etc. Floppy Disk Memory Pen Drive DVDs Hard Disk Key Points • Hardware is the physical component of a computer system. Without hardware software cannot be installed. • Input hardware is essential to give data and instruction to the computer. • Output hardware is any part of computer hardware used to communicate the results to the user. • The storage hardware of the computer holds and saves data and instructions that are entered through the Input Unit.
19 Oasis Radiant Computer Science, Book 6 Exercise 1. Answer the following questions. a. What is hardware? b. What is output hardware? How many types of output are there? List them. c. Define storage hardware with some examples. 2. Fill in the blanks: a. Hardware is the ………. components of computer system. b. ……… hardware is essential to give data and instructions. d. Keyboard, mouse, light pen, etc. are the examples of ………. hardware. e. The types of output forms are soft copy and ……….. f. The …….. hardware of the computer holds and stores data and instructions that are entered through the Input Unit. g. Computer system is nothing without the ………… 3. Write short notes on: a. Input hardware b. Output hardware 4. Project work a. Collect some pictures of input and output hardware and paste them on chart paper.
Oasis Radiant Computer Science, Book 6 20 Input and Output Devices 3 Chapter 8 Input and output of computer 8 Input devices such as mouse, keyboard and scanner 8 Output devices such as monitor, printer and speaker
21 Oasis Radiant Computer Science, Book 6 Devices connected to the computer system are called computer peripherals. The processing unit of the computer requires the input devices to accept the data and instructions and output devices to deliver the result to the user. Input devices Data and instructions are the input for the computer system. The devices that are used to accept such input and deliver them to the processing part of the computer are called input devices. They allow for communication between the user and the computer. Input devices capture data and instructions then convert them into machine code to process. There are various types of input devices such as keyboard, mouse, scanner, light and pen. Keyboard The keyboard is a standard input device that accepts the data and instructions given by the user. It accepts the text and numeric data. It is a popular data entry platform of computer. The layout of the keyboard is like that of traditional QWERTY typewriter. Technically we have two types of keyboard: Wired and Wireless. But according to the number of keys we can classify the keyboard into three types. • AT(Advanced Technology):101 keys • XT(Extended Technology):83 keys • Enhanced Technology: 103 keys Input and Output 3 Devices Chapter
Oasis Radiant Computer Science, Book 6 22 Mouse Mouse is a small handheld pointing and clicking input device. It is used to control the position of the pointer on the screen and select the options to operate the system. It has two buttons to select and control the operation. Most mouse types have the middle scroll button that supports to scroll the windows. The mouse was invented by Douglas Engelbart in 1963. According to the technology used in the mouse, it is classified as: wireless mouse, mechanical and optical mouse. Scanner It is an optical input device that captures images from photographic prints, posters, magazine pages and similar sources for computer editing and display. Scanners come in hand-held, feed-in, and flatbed types. It can scan black-and-white and colour pictures. Very high resolution scanners are used for scanning highresolution printing, but lower resolution scanners are sufficient for capturing images for ordinary work. Different types of scanners are: Flatbed Scanner Desktop Scanner, Sheet-fed Scanner, Handheld Scanner, Drum Scanner, etc. Light Pen It is an advanced technology based input device. Light pen is a pointing type input device used to draw diagram on Visual Display Unit (VDU) directly. It is connected with VDU. It is used in engineering drawing, architect design, circuit design and other several graphics and art works. It needs special type of display unit and pen to draw diagrams.
23 Oasis Radiant Computer Science, Book 6 Output Devices Devices that interact with the user and deliver results are called output devices. They are printer, monitor, plotter, speaker, etc. Output Unit is used to present soft and hardcopy of the result to the user. VDU (Visual Display Unit) and printer are commonly used Output Units. Softcopy output is shown on a display screen using visual unit and hardcopy output is printed on the paper using printer. Monitor This is a common Visual Display Unit (VDU) used to deliver output to the user. It is a softcopy output device. There are various types of monitor like CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) and LED (Light Emitting Diode). CRT (Cathode Ray Tube) Traditional monitor that looks like a television screen is CRT Monitor. It occupies more space and consumes more electric power. Ferdinand Braun developed the first Cathode Ray Tube in 1897. The cathode ray tube is an evacuated glass tube in which phosphor coated screen is used to display information. LCD (Liquid Crystal Display) A liquid crystal display (LCD) is a flat panel display that uses the light modulating properties of liquid crystals. LCDs are used in a wide range of applications, including computer monitors and television. LCDs have replaced Cathode Ray Tube (CRT) displays these days.
Oasis Radiant Computer Science, Book 6 24 LED (Light Emitting Diode) A Light Emitting Diode (LED) is a semiconductor device that emits visible light when an electric current passes through it. LED is different from the standard light bulb seen in most homes because it uses an electrified semi conductive material to produce light instead of an electrified filament. Printer Printer is an output device that prints the result on the paper. It produces a hard copy output. Printers can print all types of data like text, picture and other form of document. There are two types of printer: impact and nonimpact. Impact Printer Impact printers are the printers where characters are printed by pressing a typeface against an inked ribbon, which makes a mark on the paper. The commonly used impact printer is the Dot Matrix Printer. Non-Impact Printer Non-impact printers are the printers where there is no contact between the typeface and the paper while printing. They are much quieter than impact printers because their printing heads do not strike the paper. Laser printer is non-impact printer with high-resolution. It can print 100-200 characters per seconds. Key Points • The devices that are used to input data to the computer are called input devices. • Input device is meant for entering data and programme into the computer system for processing.
25 Oasis Radiant Computer Science, Book 6 • The keyboard is a standard input device. It is a data entry platform of computer. • These days wired and wireless type of keyboards are available in the market. • Mouse is a small handheld pointing and clicking input device that is used to control the position of the cursor on the screen. • Mouse was invented by Douglas Engelbart in 1963. • Wired and wireless mouse types are available in the market. • The different types of scanners are: Flatbed Scanner or Desktop Scanner, Sheet-fed Scanner, Handheld Scanner, Drum Scanner etc. • Light pen is an input pointing device used to draw diagram on Visual Display Unit (VDU ) directly. • The devices from which the data are displayed or printed or showed are called output devices. • Softcopy output is shown on a display screen which can be changed. • Hardcopy output is printed on the paper which cannot be changed. • Monitor is a softcopy output device used to display the information after processing. • There are various types of monitors like CRT (Cathode Ray Tube) , LCD (Liquid Crystal Display) and LED (Light Emitting Diode). • CRT monitor looks like a television screen. Ferdinand Braun developed the first Cathode Ray Tube in 1897. • The cathode ray tube is an evacuated glass tube in which phosphor coated screen is used to display information. • A liquid crystal display (LCD) is a flat panel display that uses the light modulating properties of liquid crystals . • A Light Emitting Diode (LED) is a semiconductor device that emits visible light when an electric current passes through it. • Printer is an output device that prints the result of an operation on paper, which produces a hard copy. • In impact printers, characters are printed by pressing a typeface against an inked ribbon, which makes a mark on the paper. • Laser printer is non-impact with high-resolution. It can print 100- 200 characters per seconds or 15000 lines per minute.
Oasis Radiant Computer Science, Book 6 26 Exercise 1. Answer the following questions. a. What is input hardware? Write its functions. b. What is keyboard? Name some types of standard keyboard. c. Define mouse. d. What are the types of mouse available in the market? e. For what purpose is scanner used? f. Define light pen. g. Define output device. h. What is softcopy and hardcopy output? i. Define monitor and mention its types. j. What is printer? Define impact and non-impact printers. k. Name different types of software. 2. Fill in the blanks: a. Input devices convert ………into suitable form acceptable to a computer. b. Mouse and scanner are the example of ……….hardware. c. Extended technology keyboard has …….keys. d. Mouse is also called as pointing and ……..device. e. ……….is used to capture images, posters and even text also. f. …………is mostly used by engineers for architect engineers. g. The ………..unit is used to present soft and hardcopy of result to the user. h. VDU stands for …………………….. i. Printer is an …………..device. j. ……………printers can print 100- 200 characters per second.
27 Oasis Radiant Computer Science, Book 6 3. State whether the following statements are True or False. a. Advanced technology keyboard has 101 keys. b. Mouse was invented by Charles Babbage. c. Scanner is a popular output device. d. Monitor is also called as Visual Display Unit. e. Monitor is a hard copy output. f. Impact printer is a type of printer. g. CRT monitor looks like a typewriter. h. Laser printer is a non-impact printer. 4. Write the full forms of: a. AT b. XT c. VDU d. CRT e. LCD f. LED 5. Write short notes on: a. Keyboard b. Scanner c. Monitor d. Cathode Ray Tube 6. Class activity and Project work a. Draw the picture of Keyboard, Mouse, Scanner and Monitor on a chart paper. b. Collect the pictures of various types of printers and paste them on a chart paper.
Oasis Radiant Computer Science, Book 6 28 Storage Devices 4 Chapter 8 Primary memory 8 Secondary memory 8 Optical and magnetic storage 8 Storage devices
29 Oasis Radiant Computer Science, Book 6 Storage Hardware A computer system has huge memory. Storage section of the computer holds the working data and stores them for future purposes. Computer has two types of memories: primary and secondary. Both memories are equally important for the computer system. Primary Storage Primary memory holds the working data and instructions. It is generally made up of semiconductor device. Primary storage is also called main memory which holds instructions and data for rapid and direct access by the central processing unit (CPU). Primary memories are directly attached to the processing part of the computer. There are two types of primary memory. They are Random Access Memory and Read Only Memory. RAM (Random Access Memory) It is primary memory which is temporary in nature. It holds the working data and it will become empty when power is switched off. So RAM is called volatile memory. It is also known as temporary memory because data is stored in temporary form and it is placed in temporary form. It is different from non-volatile memory such as hard disks and flash memory. This is also called working memory. There are two types of RAM. They are (SRAM) Static Random Access Memory and (DRAM) Dynamic Random Access Memory (DRAM). Storage Devices 4 Chapter
Oasis Radiant Computer Science, Book 6 30 Difference between Static and Dynamic RAM Static Random Access Memory ( SRAM) Dynamic Random Access Memory (DRAM) It only stores data and programmes if power source is ON. It stores information in very short time if power source is ON. It is expensive. It is cheap. It does not need refreshing circuit. It needs to be refreshed. It is not widely used memory. It is widely used memory. ROM (Read Only Memory) ROM is a non-volatile memory. It is also called non-erasable or permanent memory. It is designed to perform a specific function and cannot be changed. There are four types of ROM. They are: • PROM - Programmable Read Only Memory • EPROM - Erasable Programmable Read Only Memory • EEPROM - Electrically Erasable Programmable Read Only Memory • Flash EEPROM Memory Random Access Memory (RAM) Read Only Memory (ROM) It only stores data and programmes if power source is ON. It stores information in very short time if power source is ON. It is expensive. It is cheap. It does not need refreshing circuit. It needs to be refreshed. It is not widely used memory. It is widely used memory. Secondary Storage Memory section which is connected with the data cable and not directly attached to the processing part of the computer is called secondary storage. It is also called external storage or Auxiliary Memory. It stores several programmes, documents, data, etc. The programmes that you run on the
31 Oasis Radiant Computer Science, Book 6 computer are stored in secondary memory. Whenever the results are saved, they will be stored in the secondary memory. They are slower and cheaper than the primary memory. Some of the commonly used secondary memory devices are Floppy disk, Hard disk, CD, DVD, etc. Floppy Disk It is a very portable storage device. In 1972, IBM launched Floppy diskette in market to store data and programmes. Floppy is made up of Mylar plastic or Polly vinyl plastic. Its storing capacity is 1.44 to 2 MB and rotates with speed of 360 rpm (revolution per minute). Now-a-days this disk is replaced by other storage media like pen drive. Hard Disk Fixed disk which can store huge amount of data is Hard Disk. It is the most popular type of storage media for every type of PC. The first hard disk was developed in 1956. At the early stage, it was the size of a dishwasher, with fifty platters. Seagate technology announced the first Winchester 5.25” hard disk drive with four platters capacity of 5MB data in 1980. We have various capacity of hard disks from Gigabytes to Terabytes these days. It is represented as C, D and E drive in computer system. Hard Disk has the following advantages over floppy disk. • Hard disk can store large amount of data than floppy disk. • Hard disk can store data for longer time compared to floppy disk. • Hard disk is better protected from dust, smoke and external heat than floppy disk. • Data are safely stored in hard disk than that in floppy disk. Optical Drives Disks that can store the data in terms of optical spot are called optical disks. Optical drives are more commonly known as CD and DVD drives. They are considered optical because the drive uses a laser to see the data etched onto the plastic disk.
Oasis Radiant Computer Science, Book 6 32 Now-a-days all computers have DVD and CD drives. DVD drives are becoming a new standard in portable data storage. Compact Disk (CD) Portable optical disk specially used to store the audio, visual, text and picture data are CD. Compact Disk (CD) is a small optical disc used for the storage of digital data. It is covered with a transparent coating so that it can be read by a laser beam. The first Compact Disk (CD) was developed by Sony and Philips Corporations to store music in early 1980s. DVDs (Digital Versatile Disks) Advanced optical disk frequently used to store the audio, video, text and picture data are DVD. It is also called Digital Versatile Disk. Its storing capacity is at least 15 times greater than a CD-ROM. A DVD can hold approximately 4.7 to 20 gigabytes (GB) of information. The DVD of 4.7GB, 8.5GB, 20GB are available in the market. It is also called Super Density Disk (SD). It is available in two formats: Video Format and DVD-ROM (Read Only Memory) Format. The DVD- Video Format is used for movies and DVD-ROM Format is used to store interactive games, photographs, videos, etc. Key Points • The storage unit of the computer holds and stores data and instructions that are entered through the Input Unit. • Primary memory is also called main memory, which holds instructions and data for rapid and direct access by the computer’s central processing unit (CPU). • The primary memory is temporary in nature. The data is lost when the computer is switched off. • The cost of the primary storage is higher compared to the secondary storage. • RAM is volatile memory. It is also called temporary memory. It loses its contents once power is cut off.
33 Oasis Radiant Computer Science, Book 6 • ROM is non-volatile and is also called non-erasable or permanent memory. • Secondary storage is also called Auxiliary Memory. It stores several programmes, documents, data bases, etc. • In 1972, IBM launched Floppy diskette in the market which is a portable storage device. • Hard Disk is the most popular type of storage media for all types of computers. • First hard disk was developed in 1956. • Hard disk can store larger amount of data than floppy disk. • Optical drives are more commonly known as CD and DVD drives. • Compact Disk (CD) is used for the storage of digital data. • A digital video disk (DVD), also called Digital Versatile Disk, is an optical data disk that can hold multimedia information and data storage. • DVDs of 4.7GB, 8.5GB, 20GB are available in the market. Exercise 1. Answer the following questions. a. What is the use of storage hardware? b. Define primary memory with its types. c. What are RAM and ROM.? d. Differentiate between SRAM and DRAM. e. Discuss various types of ROM. f. What is secondary storage? g. Define hard disk and floppy disk. h. List some advantages of Hard Disk. i. What is Compact Disk? j. What is DVD? What is the minimum and maximum storage capacity of DVD? 2. Fill in the blanks. a. Primary memory is also called ……….. b. The primary memory is ………..in nature.
Oasis Radiant Computer Science, Book 6 34 c. The two types of primary memory are RAM and ……… d. The two types of RAM are SRAM and ……………… e. PROM is a type of ………….. f. In ….... IBM launched floppy disk in the market. g. The storage capacity of floppy disk is measured in …….. h. Hard disk can store ………data than floppy. i. Compact disk is a small ……….. disk used for the storage of digital data. j. The storage capacity of DVD is …….times greater than a Compact Disk. 3. State whether the following statements are True or False. a. RAM is a secondary memory. b. The cost of primary memory is higher compared to the secondary memory. c. SRAM is a type of PROM. d. Static Random Access Memory is cheaper than Dynamic Random Access Memory. e. Floppy disk can store more data than hard disk. f. First hard disk was developed in 1950 AD. g. The first CD was developed by Sony and Phillips Corporations. h. Primary memory and secondary memory do the same function. i. ROM is a volatile memory. j. Compact disk cannot store the digital data. 4. Write down the full forms of: a. RAM b. ROM c. SRAM d. DRAM e. PROM f. EPROM g. EEPROM h. CD i. DVD j. CD-RW k. CD-ROM l. DVD ROM 5. Write short notes on: a. Random Access Memory b. Floppy Disk c. Compact Disk d. Digital Video Disk 6. Project work a. Make a list of primary and secondary storage used in the computer system. b. Draw the figure of RAM, Floppy Disk, Hard Disk and Pen Drive.
35 Oasis Radiant Computer Science, Book 6 Computer Software 5 Chapter The concept of software Types of software System and utility software Applications software
Oasis Radiant Computer Science, Book 6 36 Software The computer system is controlled and managed by the use of sets of instructions and programmes. They are called the software. We can define software this way: “Software is the collection of programmes and other associated documents that help to control, manage and integrate the components of computer system to perform a specific task.” Without software, a computer system will be an idle object which cannot perform any task. Computer system is nothing without the software. These programmes are organised and collected in a systematic order to tell the computer what to do and how to do it. For example, software instructs the hardware, what to display on the user's screen, what kinds of input to take from the user and what kinds of output to generate. So software works like a driver of a car to drive and control the hardware system smoothly. Types of Software Basically software system is designed for different purposes. Some are designed to control the system and some are designed to support day to day activities of the users. We can classify them as system, application and utility software. ● System software ● Application software ● Utility software Computer Software 5 Chapter
37 Oasis Radiant Computer Science, Book 6 System Software Basic software that gives life to the computer system is system software. It helps to activate the computer system and provides operating environment for other application software. It is developed for the computer system so these are called system software. Its primary work is to control, integrate and manage an individual’s hardware components of the computer system. This software provides an operating and programming environment where the programmer and user can create the application software for their day to day application. Application Software Application software is developed for specific purpose, so we can define it as user’s purpose software. This software is developed using high level language in the form of creative project work by the software industries. There are many types of application software. They are MS Word, MS Excel, MS PowerPoint, MS Access, etc. Utility Software System software which are developed to maximise the utilisation of the computer resources are utility software. Special types of system software Fig: Windows 8 on Tablet PC
Oasis Radiant Computer Science, Book 6 38 which are used to maximise the utility of the hardware devices and computer system are utility software. We can use these software for scanning the hard disk, repair and maintenance of computer system and removing the viruses of computer. Popular utility software are scandisk, antivirus and other toolkits used to repair and maintain the computer. 1. Answer the following questions. a. What is software? b. What are the various types of software? c. What is system software? d. Why is application software developed? Name some application software. e. Define utility software with some examples. 2. Fill in the blanks: a. Without ………software cannot work. b. MS PowerPoint is a …………..software. c. Antivirus programme is a ……….software. d. We can use utility software to …….and maintain the computer system. Exercise
39 Oasis Radiant Computer Science, Book 6 3. State whether the following statements are True or False. a. Software needs hardware to work. b. Software is the collection of programmes. c. Software tells the computer how to work and how to operate. d. Antivirus is system software. e. PowerPoint programme is system software. f. The function of application software and system software is same in the computer system. g. Application software is developed by using low level language. 4. Elaborate on: a. Application software b. Utility software 5. Project work a. Make a list of any five system software and utility software with the help of your teacher.
Oasis Radiant Computer Science, Book 6 40 Operating System 6 Chapter 8 The concept of operating system 8 Types of operating system 8 Use of MSDOS 8 Use of Windows system
41 Oasis Radiant Computer Science, Book 6 Introduction The common platform between the user and computer system is called an operating system. It is the most popular system software that enables the computer hardware to communicate and operate with the computer software. Without operating system, computer does not function. An operating system (OS) is a set of software that manages computer hardware resources and provides common services for computer programmes. The main job of operating system is to manage files on hard drive and control peripherals, like printers, scanners, keyboard, mouse, etc. Some common features of operating system are: • It provides the common interface for the user and computer system. • It controls hardware resources like Input, Output and other peripheral devices. • It recognises the hardware components attached to the computer system. • It gives security to the system by assigning password. • It manages the use of main memory. • It interprets the command given to the computer system. Types of OS OS is the system software and its main function is to provide working platform to the computer. According to the interface used and the processing style, we have different types of OS. Some popular OS are single user processing, Operating System 6 Chapter
Oasis Radiant Computer Science, Book 6 42 multi user, single tasking and multi-tasking operating systems. According to the interface of the OS, we have two types of OS. - Command or Character User Interface (CUI) - Graphical User Interface (GUI) Command User Interface is a single user and single tasking traditional OS like Microsoft Disk Operating System (MSDOS). GUI is the advanced OS with multi user, multi programming platform like a Windows system. Microsoft Disk Operating System (MS-DOS) CUI operating system developed by Microsoft Company is MSDOS. Microsoft Disk operating system is the most basic form of operating system. Commonly known as DOS, the disk operating system is specially designed to provide support to secondary devices of computer system. Disk operating system establishes an operational link between the users and outside devices of computer system. It controls the overall operating system of modern computers. It has the Character Use Interface (CUI) and interprets the command to perform the task. Functions of Disk Operating System MSDOS has the same features like the other OS. The main function of disk operating system is to coordinate the user and outside devices used in the computer system. Disk operating system converts the commands into the machine readable form. DOS also converts the error messages generated by computers into an understandable format. It helps to start the computer by loading system files and accepts the command to function. File and Directory File is a collection of related data. The name of each file must be unique within the directory where it is stored. File has a unique path name in the
43 Oasis Radiant Computer Science, Book 6 file system. Directory is the location where we can store various other files and directories. It is like a table of contents of your book. We can store so many files and also can create a sub-directory inside a directory. In Windows system, directory is called folder. Folders are the collection of files. Windows Operating System Microsoft Windows is a Graphical User Interface (GUI) based operating system developed by Microsoft Corporation. The first version of Windows was released in November 1985. In August 1995, Windows 95 was released. Windows XP was released in October, 2001. Newer versions of Windows operating system are Windows vista, Windows 7 and Windows 8, Windows 10. Starting Windows Start the computer, Windows will automatically get started. We will see the following components on the Windows system. The taskbar view When multiple windows are open in a programme, the icon will look “stacked” on the taskbar. • Aero Peek will show you a thumbnail of each window when you hover the mouse over the icon on the taskbar.
Oasis Radiant Computer Science, Book 6 44 • If you wish, you can change the order of the icons by clicking and dragging the icon to whatever space you desire on the taskbar. Pin a programme to the taskbar Placing the programme on the taskbar is called Pin a programme. You can place programmes to the taskbar and access them with a single click of the mouse. • To Pin a programme, drag the programme to the taskbar from desktop or other places and release. • To Unpin a programme is to remove the programme name from the taskbar. To unpin simply right-click on the icon and select Unpin. Access a Jump List A Jump List is like a mini-menu for a programme. It allows quick access to recent files, frequently viewed items, performance tasks, and more. For example, you can select frequently used websites with a simple click from the Internet Explorer Jump List.
45 Oasis Radiant Computer Science, Book 6 • Right-click an icon to open the programme’s Jump List. • Select the programme to open from the jump list. Show desktop When you are working with other programmes and you need to go to the desktop you have to choose this option. Follow the given steps to show the desktop without closing windows: • Hover the mouse over the Show desktop button. • The windows will become transparent, allowing you to see the desktop. • Click the Show desktop button to close the windows. • Click again, and the windows will return. Personalise your desktop’s background and themes
Oasis Radiant Computer Science, Book 6 46 Windows has some amazing themes and backgrounds. They include vivid photography and digital artwork themes that use colour and glass effects in an attractive way. Themes and backgrounds • In the Search bar of the Start Menu, type and select Personalisation. Alternatively, you can right-click the Desktop and select Personalise. • Review and select a desired theme or background. You can search online for more themes by selecting Get more themes online in My Themes. Personalise font settings You can adjust the font settings and ClearType on your desktop based on your preferences. To change the font: 1. From the Search bar in the Start Menu, type and select Fonts.
47 Oasis Radiant Computer Science, Book 6 2. Select the font you desire from the Fonts pane. To change font size: 1. Adjust the font size by selecting Change Font Size from the menu on the left of the Fonts pane. 2. Select the desired font size, and click Apply. Please note that a larger font size may interfere with how some items are displayed on the screen.
Oasis Radiant Computer Science, Book 6 48 Gadgets Gadgets are programmes that run on your desktop so you can see information at a glance. Gadgets can give you information about the weather, date and time, news, traffic, and more. To add gadgets to your desktop: 1. Right-click your desktop and select Gadgets. 2. Select and drag the gadgets you desire, and place them anywhere you want on the desktop. Finding Your Files with Search and Libraries Libraries are collections of your stored content that can be easily accessed through the Desktop Search function. Libraries do not replace your folders; they simply house them in a single collection. When files are placed in a Library, their properties are indexed by the Search function. There are four default Libraries in Windows : Documents, Pictures, Music, and Videos. Windows Explorer Windows Explorer helps to find and manage files and folders in an easy manner.
49 Oasis Radiant Computer Science, Book 6 • Click the folder icon on the taskbar to open Windows Explorer. • You will get a dialogue box: • Get your content by double-clicking folders, clicking on the Back and Forward buttons and by clicking on headings in the Address bar. • Preview files by selecting the Show the Preview pane button. • When you double-click a file, it will open in the default programme.
Oasis Radiant Computer Science, Book 6 50 To change the view of the content in your folders You have several options for how you can view content in your folders. • To change the view, select the View button and choose your preference. Select as Large icons, Extra Large icons, Small Icons, Details, Tiles and Content. To change how your content is arranged Depending on the Library, you can Arrange content by month, day, rating, and other factors. • Select the Arrange by button, and choose your preference. Using Search You can search the files and folders from the disk. Use the following steps: 1. Locate the Search bar at the top right corner of the Windows Explorer pane. 2. Start typing a file name or keyword. 3. Search will start displaying matching items even before you finish typing.