Flipp Book class 9

Lab Activities 1. Perform the following activities in the com- puter Lab with the supervision of computer teacher, then prepare the activities report. b. List out the various input/output devices used in your com- puter lab. c. Get old computer system and recognize the connection port. c. Disassemble and assemble the computer system. 2. Watch the YouTube Video in the following topics or Scan the following image: a. Printing process of impact and non-impact printers demo b. Disassemble and assemble computer system. c. OMR scanning Process Project Work 51 1. Prepare a depth project work in any one of the following topic: a. Soft Copy Output Devices b. Hard Copy output devices The project work includes the following a. Text b. Image c. Illustration figure d. Video clip e. Digital Presentation Smart Computer Science Book-9

Computer Memory CHAPTER 4 Chapter Includes • Introduction of Computer Memory • Primary Memory & its type • Register memory • Secondary Memory its & Type • Cache memory • Unit of Memory Measurement INTRODUCTION Memory is an essential hardware component of the computer that is assembled on the motherboard. It is the storage space in the computer that is used to store data, information, programs on a temporary or permanent basis. The memory is divided into a large number of small parts called cells, which is also called memory location. Each location or cell has a unique address, which varies from zero to memory size minus one. For example, if the computer has 65 kb words, then this memory unit has 65 * 1024 = 66560 memory locations. The address of these locations varies from 0 to 66559. On behalf of space or location, The computer memory is categorized into four types: i) Register memory ii) Cache memory iii) Primary memory iv) Secondary memory REGISTER MEMORY Register memory is the smallest and fastest memory in a computer. It is the tiny data holding particle which is located in the CPU in the form of registers. They temporarily hold frequently used data, instructions, intermediate result and memory address which are being processed in the CPU. All the data are required to pass through registers before they can be processed. So, this memory is used by the CPU. Specially, this memory is used by CPU to process the data and prepare the result. 52 Computer Memory

CACHE MEMORY Cache memory is a very high speed semiconductor memory. In the earlier computer, cache memory was located between the CPU and RAM as a separate chip on the motherboard, but in the modern CPUs, it is integrated with directly into the CPU chip. It is faster than the main memory (RAM). The CPU can access it more quickly than the main memory because it is directly integrated with CPU and CPU looks the cache first to get the required data and instruction. So, it helps to improve the performance of the CPU. It plays the role of buffer between the CPU and main memory. Cache memory holds the data and programs which are most frequently used by the CPU. So, it makes sure that the data is instantly available for CPU whenever the CPU needs. In other words, if the CPU finds the required data or instructions in the cache memory, it doesn't need to access the primary memory (RAM). So, it is also called reserved memory of RAM and internal memory of the CPU. PRIMARY MEMORY Primary memory is also commonly known as main memory, may also refer to internal memory or primary storage. All those types of computer memories that are directly accessed by the processor using data bus are called primary memory. It is used for storing data, instructions and programs while they are being used in a computer. It is the only memory which is directly accessible to the CPU. The data and instruction required to be processed resides in the main memory. It has a limited capacity. It is generally made up of semiconductor device. These memories are not as fast as registers but It is usually faster to read/write, expensive and low storage capacity compared to secondary memory. Basically it is divided into two subcategories: i) RAM (Random Access Memory) ii) ROM (Read Only Memory) RAM (Random Access Memory) RAM is the main memory or internal memory of the computer for storing data, program, and processed result temporarily for current use. Smart Computer Science Book-9 53

When data and program are fetched through the input device or secondary storage, they are stored first in the RAM. All the essential program to run the computer are stored in this memory. So, it is also called system memory. It stores data until the machine is working, as soon as the machine is switched off due to any circumstances, all the information are erased from this section. So, it is also called volatile memory. Hence, a backup Uninterruptible Power System (UPS) is often used with computers. RAM is a small memory, both in terms of its physical size and storage capacity, but it is a faster memory because it is randomly accessible and made by semiconductor silicon chip. The RAM is classified into two types: i.) DRAM ii) SRAM SRAM (Static Random Access Memory) As the name implies static which indicates the memory retains its contents as long as power is being supplied. However, data is lost when the power gets down or switched off due to volatile nature. SRAM chips use a matrix of 6 transistors and no capacitors. Transistors do not require power to prevent leakage, so SRAM need not be refreshed on a periodically. So, it is very fast access and works as cache memory. DRAM (Dynamic Random Access Memory) DRAM, unlike SRAM, must be continually refreshed in order to maintain the data. It is an integrated circuit (IC) made of millions of transistors and capacitors. A memory cell of a DRAM has one transistor and one capacitor and each cell stores a single bit of data either 0 or 1 in its capacitor. The transistor acts as a switch that allows the electric circuit on the memory chip to read the capacitor and change its state. Capacitors needs to be refreshed continuously to maintain its data otherwise it would forget what it is holding. This is achieved by placing the memory chip on a refresh circuit that rewrites the data several hundred times per second. So, It is slower than SRAM. ROM (Read Only Memory) ROM is a memory device or storage medium that stores information permanently. It is also the primary memory unit of a computer along with RAM. It is called read only memory as we can only read the programs and data stored on it but 54 Computer Memory

cannot write on it. ROM stores programs containing instructions that help to start up a computer which is known as a bootstrap. However, there are some types of ROM where you can modify the data. Broadly the ROM comes in the following types: i) MROM(Masked Read Only Memory) ii) PROM (Programmable Read only Memory) iii) EPROM(Erasable Programmable Read Only Memory) iv) EEPROM(Electrically Erasable Programmable Read Only Memory) v) Flash ROM MROM(Masked Read Only Memory) It is the oldest technology of read only memory (ROM). Nowadays it is outdated, it is not used anywhere. MROM, in which programs and instructions are stored at the time of manufacturing by the manufacturer. So it is programmed during the manufacturing process and can't be modified, reprogrammed, or erased later. So, its name had implied as ROM which is still common and popular. PROM (Programmable Read only Memory) PROM is a blank chip. It is manufactured as blank memory and programmed after manufacturing. You have to purchase blank one and then store the program according to your requirement with the help using a special tool and technique called a PROM programmer or PROM burner. However, once the chip has been programmed, the recorded information can not be changed, so it is also called one-time programmable device. EPROM(Erasable Programmable Read Only Memory) EPROM can be erased many times and reprogramed as we like. Ultraviolet light is passed in a specific frequency with a quartz window for around 40 minutes to erase the data. When it is exposed to the ultraviolet light, it won't retain the content, it is totally blank. Now, using the special device called a PROM programmer or PROM burner, you can reprogram the EPROM. EEPROM(Electrically Erasable Programmable Read Only Memory) EEPROM is a type of read only memory that can be erased and reprogrammed repeatedly. It is erased and reprogrammed electrically without using ultraviolet light. The data in this memory are written or erased one byte at a time; byte per byte. So it is faster than EPROM. The BIOS (Basic Input Output System) of a Smart Computer Science Book-9 55

computer is stored in this memory. FLASH ROM It is an advanced version of EEPROM. It stores information in a block of memory cells. You can delete or write blocks of data around 512 bytes at a particular time. Whereas, in EEPROM, you can delete or write only 1 byte of data at a time. So, it is faster than EEPROM. The BIOS (Basic Input Output System) of many modern computers is stored on a flash ROM. SECONDARY MEMORY The devices which are connected to the computer for storing data, programs, and information permanently are known as a secondary memory. It always retains stored data even when the computer is turned off or until this data is overwritten or deleted, so it is called non volatile memory, external memory, auxiliary storage, or backup memory. It is also used for carrying data from one computer to another. Secondary memory is not directly accessible to the CPU. It is accessed indirectly via input/output routines. So, it is slower than the main memory for read/write. When the secondary memory is accessed, the contents of secondary memories are first transferred to the main memory, and then the CPU can access it. However, it is cheaper, larger storage capacity and portable memory. HDD (Hard Disk Drive), SSD(Solid State Disk), CD, DVD are examples of secondary storage. The common types of secondary storage are: i) Magnetic Memory ii) Flash memory iii) Optical Memory Magnetic Memory Magnetic memory uses the property of magnet for storing data. It is in use since first generations of computer as a secondary storage. It contains data storing surface coated with magnetic oxide. Magnetic memory is further divided as: i) Magnetic Drum ii) Magnetic tape iii) Magnetic disk Magnetic Drum Magnetic drum contains a metallic drum coated with magnetic oxide on the outer surface of the drum, data is stored in this surface. It was in use in first and second generations of computer to store data. 56 Computer Memory

Magnetic tape Magnetic tape contains thin plastic ribbon, only one side of the ribbon is used for storing data. The data storing side is coated with magnetic oxide. It is a sequential access memory. So, the data read/write speed is slower. It is mainly used for storing data and playing audio and video. It is highly reliable but old technology. It requires magnetic tape drive for reading and writing data. Magnetic disk Magnetic disk contains a circular disk made of metal or plastic. Both sides of the disk are usually used for storing data. The disk is coated with magnetic oxide. The disk is divided into multiple concentric circles known as track. Tracks are further divided into the small area known as sectors. Data are stored in sectors. Example: Hard disk, floppy disk, zip disk, super disk, Winchester disk, Jaz disk. HDD (Hard disk Drive) The hard disk is also known as a hard drive. It is used as the main storage device of the computer. The hard disk is located within a drive unit on the computer's motherboard and comprises one or more platters packed in an air-sealed casing. The data is written on the platters by moving a magnetic head over the platters as they spin. The data stored on a computer's hard drive generally includes the operating system, installed software, programs and the user's files and pictures, music, videos, text documents, etc. It uses 2-4 metallic disk (platter). The disk is usually made of aluminum. Both sides of the disk are used for storing data except the upper side of the uppermost disk and lower side of the lowermost disk. The data storing surface is coated with magnetic oxide. Each data storing surface contains separate read/write head. During data read/write process platter rotates at the rate of 3600-15000 rpm(revolution per minute). Hard disk is also known as hard drive because both data storing disk and data read/write components are combined together. It has Smart Computer Science Book-9 57

the storage capacity of few Mega Bytes to Terra Bytes. Flash Memory Flash memory is a solid-state chip that maintains stored data without any external power source. It is commonly used in portable electronics and removable storage devices, and to replace computer hard drives. Solid-state drives are a practical replacement for large hard drives with flash memory chip. SSD (Solid State Disk) An SSD is a type of mass storage device similar to a hard disk drive (HDD). It supports reading and writing data and maintains stored data in a permanent state even without power. Internal SSDs connect to a computer like a hard drive, using standard IDE(Integrated Drive Electronics) or SATA(Serial Advanced Technology Attachment) connections. While SSDs serve the same function as hard drives, their internal components are much different. Unlike hard drives, SSDs do not have any moving parts. So, they don't have to \"spin up\" and no need to move a drive head to different parts of the drive to access data. Therefore, SSDs can access data faster than HDDs. Instead of storing data on magnetic platters, SSDs store data using flash memory and rely on an embedded processor. So it offers many advantages over SSD, such as faster access time, noiseless operation, less power consumption, defragmenting is not necessary, lighter and more. Pen drive Pen drive is a compact secondary storage device. It is also known as a USB flash drive. It connects to a computer via a USB port. It is mainly used for transferring data between computers. It is the most popular data-storage devices among consumers. Due to the micro, lightweight and handy, 58 Computer Memory

a pen drive can be easily carried from place to place. The flash memory chip is used in the pen drive. It has faster read/write speed compared to magnetic memory. Pen drive has storage capacity of few MB(Mega Byte)-GB(Giga Byte). It is also called plug and play device. SD Card (Secure Digital Card) SD card is a micro secondary storage. It includes the flash memory to store data and information. It is most often used in portable and mobile devices such as smart phones and digital cameras. You can remove it from your device and see the things stored in it using a computer with a card reader. Optical Memory Optical memory uses the light beam for reading and writing data. It is mainly used for storing audio/video, backup as well as for carrying data. It requires an optical drive for its reading/writing operation. Its read/write speed is slower compared to hard disk and flash memories. CD, DVD, BD, are examples of optical disk. CD (Compact Disk) It is a an optical storage, which can store about 700 MB data. The CD contains hard circular plastic, single side of this plastic is coated by aluminum alloy. This alloy stores data. The CD requires CD drive for its operation. Data can be stored once in the CD during the manufacturing time. After storing data it is converted into the CD-ROM (Compact Disk Read Only Memory) which cannot be erased. CD are two types: i) CD-R (Compact Dic-Recordable) ii) CD-RW (Compact Disc-ReWritable) DVD (Digital Versatile Disk) It is an optical storage device having the storage capacity 4.7 GB to 17 GB. DVDs are widely used for storing, distributing and viewing movies, software, programs and other data files. Its shape and size is similar to CD, but high storage capacity due to different chemical composition and data is compressed before Smart Computer Science Book-9 59

storing. It requires DVD drive for its operation. Types of DVD are: DVD-R, DVD- ROM, DVD-RW. BD(Blueray Disk) Blu-ray is an optical disk format such as CD and DVD. It was developed for recording and playing high-definition (HD) video and for storing large amounts of data. A single Blu-ray disc can hold up to 25 GB of data. Dual-layer Blu-ray discs will be able to store 50 GB of data. MEMORY MEASUREMENT Computer memory contains may cells, which is known as a storage location. Each cell of memory can store a bit (binary digit) which is the smallest unit of memory that represents 0 or 1. All the information can be stored in the computer memory in the form of such binary digits. Any alpha character and special symbols represent 8 bits, for example: Capital 'A' represents 0100 0001, in this way, any numeric digit represent four bits. For example 9 represents : 1001. A collection of 4 bits called nibble and a collection of 8 bits called a byte. 1024 bytes=1 KB (Kilo bytes) . The summary of the memory measurement is illustrated by following table. Unit Equivalent Bit 0 or 1 Nibble 4 bits=1 nibble Byte 8 bits= 1 byte Kilobyte 1024 bytes =1 Kilobyte Megabyte 1024 Kilobyte =1 Megabyte Gigabyte 1024 Megabyte =1 Gigabyte Terabyte 1024 Gigabyte =1 Terabyte Petabyte 1024 Terabyte =1 Petabyte Exabyte 1024 Petabyte=1 Exabyte Zettabyte 1024 Exabyte =1 Zettabyte Yottabyte 1024 Zettabyte =1 Yottabyte 60 Computer Memory

Points to Know • Memory is the storage space in the computer that is used to store data or programs on a temporary or permanent basis for using in an electronic digital computer. • Register memory is the tiny data holding particle which is located in the CPU. • Cache memory holds the data and programs which are most frequently used by the CPU. • All those types of computer memories that are directly accessed by the processor using data bus are called primary memory. • RAM is the main memory or internal memory of the computer for storing data, program, and processed result temporarily for current use. The RAM is two types: i.) DRAM ii) SRAM. • ROM stores such instructions that are required to start a computer. • ROM stores such instructions that are required to start a computer which is known as a bootstrap. MROM, PROM, EPROM, EEPROM, Flash ROM are its types. • The devices which are connected to the computer for storing data, programs, and information permanently are known as secondary memory. Examples: HDD, SSD, CD, DVD, pen drive, SD card, etc. • Each cell of memory can store a bit (binary digit) which is the smallest unit of memory that represents 0 or 1. Terms to Know Assemble : Gather together in one place for a common purpose Register : One of a small set of data holding places that are part of the computer processor. Semiconductor : A substance, usually a solid chemical element or compound, that can conduct electricity. Data bus : A group of electrical wires used to send information (data) between two or more components. Transistors : A semiconductor device with three connections used to amplify or switch electronic signals and electrical power. Capacitors : A device used to store an electric charge, consisting of one or more pairs of (conductor) electric charger separated by an insulator. Integrated Circuit : A set of electronic circuits on one small flat chip of semiconductor material that is normally silicon. Bootstrap : A program that initializes the operating system (OS) during startup the computer. Ultraviolet light : A type of electromagnetic radiation that makes black-light posters glow. Smart Computer Science Book-9 61

Auxiliary storage : A data storage device that is not the main memory of a computer. Magnetic oxide : Solvent prepared with magnetic material and iron used as a sensitive coating on magnetic tape. Track : A circular path on the surface of a disk. Sector : A subdivision of a track on a magnetic disk or optical disc. Drive : A device which allows a computer to read from and write on to computer disks. Card reader : An electronic device that reads and transfers data from various portable memory storage devices. Light beam : A directional projection of light energy radiating from a light source. Aluminum alloy : A chemical composition where other elements are added to pure aluminum. Intermediate result : A quantity or value derived from an operation performed in the course of a program or subroutine which is itself used as an operand in further operations. Memory : A place which is capable to store and retain information. Worksheet Objective Questions 1. Fill in the blanks: a. The memory is divided into a large number of small parts called ........................ b. ..................... memory is the smallest and fastest memory in a computer. c. Cache memory is a very high speed ........................ memory. d. .............................. memory is the internal memory of the CPU. e. ............................memory is also known as the main memory of the computer. f. Primary memory is directly accessible to ....................... g. RAM is the .......................... memory of the computer. h. DRAM made of millions of ............................ and ................................ i. .............................. is programmed during the manufacturing process and can't be modified. j. ......................... is manufactured as blank memory and program after manufacturing. 62 Computer Memory

k. The tool and technique used to store the program in PROM is called .................. l. ........................... can be erased many times and reprogrammed using ultraviolet light . m. The accessed contents of secondary memory are first transferred to ................. n. Magnetic disk contains a ........................... disk made of metal or plastic. o. Hard disk is known as ............................. .......................... p. The data is written on the ............................ by moving a magnetic head. q. Pen drive is connected to the computer via ..................... port. r. ................................ is a practical replacement for large hard drives. 2. Write 'T' for true and 'F' for false statements: a. Memory is assembled on the motherboard. b. Register memory is located in the CPU. c. CPU never access the RAM. d. Cache memory is the reserved memory of RAM. e. RAM is an auxiliary memory. f. Primary memory is faster, expensive and low in storage capacity than secondary memory. g. Primary memory is faster than register memory. h. Ram is a temporary memory. i. SRAM works as cache memory. j. Transistors act as switches in the DRAM. k. Capacitor stores single bit of data in DRAM. l. MROM is outdated memory. m. EEPROM is erased electrically without using ultraviolet light. n. Magnetic drum was in use in the first and second generation as a storage device. Smart Computer Science Book-9 63

o. Magnetic tape is a sequential access storage device. p. Magnetic disk is coated with the magnetic oxide. q. Data are stored in sectors in the magnetic disk. r. Hard disk uses two metallic disks (platter). s. Both side of all the disks (platters) are used for storing data. t. Flash memory is a solid state chip. u. Pen drive is known as USB flash drive. v. CD is converted into the CD-ROM after storing data. 3. Write the full forms of: a. CPU ............................................ b. HDD .............................................. c. RAM ............................................ d. SSD ................................................ e. ROM ............................................ f. bits .................................................. g. UPS............................................. h. rpm ............................................. i. DRAM .......................................... j. KB ................................................ k. SRAM .......................................... l. CD-R ............................................ m. IC ............................................... n. CD-RW............................................. o. MROM ........................................ p. CD-ROM......................................... q. PROM ......................................... r. DVD-R............................................. s. EPROM ....................................... t. DVD-RW......................................... u. BIOS ........................................... v. EEPROM........................................ w. CD ............................................. x. BD................................................... y. DVD ............................................. z. USB ............................................... aa. MB ............................................. bb. GB ................................................. 64 Computer Memory

4. Circle for the correct option: a. Intermediate result is stored in the: i) Register ii) RAM iii) ROM iv) All of these b. Cache memory plays the role of buffer betwwen : i) CPU and RAM ii) CPU and ROM iii) CPU and HDD iv) CPU and SSD c. Types of primary memory: i) RAM ii) ROM iii) Both i) and ii) iv) None of these d. Types of RAM : ii) SRAM iii) Both i) & ii) iv) None of these i) DROM e. Backup of power system: i) BIOS ii) UPS iii) SSD iv) All of these f. Circular disk on which magnetic data is stored in a hard disk drive. i) Platter ii) Magnetic disk iii) Solid state disk iv) All of these g. The memory which needs to refresh periodically: i) SRAM ii) DRAM iii) PROM iv) EPROM h. DRAM uses the : iii) Both i) and ii) iv) All of these i) Capacitors ii) Transistors i. Secondary memory is known as: i) Auxiliary memory ii) Backup memory iii) External Memory iv) All of these j. Types of secondary memory: i) Magnetic memory ii) Optical memory iii) Flash Memory iv) All of these k. The data stored on a hard disk includes : i) Opearting system ii)Installed software iii) Text document iv) All of these l. Optical disks are : ii) DVD iii) BD iv) All of these i) CD m. The storage capacity of CD: i) 700 MB ii) 25 GB iii) 17 GB iv) 4.7 GB Smart Computer Science Book-9 65

5. Match the following: a. Primary memory Bootstrap b. Main memory Magnetic oxide c. DRAM Optical memory d. ROM Magnetic tape e. EEPROM RAM f. Magnetic memory ROM g. Plastic ribbon Flash memory h. Magnetic disk Speed up the CPU i. Light beam Exabyte j. Memory unit Periodically Refreshed k. Cache memory Concentric circle 6. Write the terms for the following: f. The memory which is used to store data and program a. Smallest part of memory. permanently. Ans:......................................... Ans:......................................... b. Smallest and fastest memory located in the CPU. g. The disk which is used to install programs and operating system. Ans:......................................... c. Collection of 1024 bytes. Ans:......................................... h. The memory which is commonly Ans:......................................... used in the removable and d. The memory which does not need portable electronic device. to refresh periodically. Ans:......................................... Ans:......................................... e. The program, which controls the i. A micro storage device that input-output routine. includes flash memory. Ans:......................................... Ans:......................................... 66 Computer Memory

j. Memory which is mainly used for j. The memory which is used to store storing , audio, video, software, data, program, and processed backup as well as carrying data. result temporarily for current use. Ans:......................................... Ans:......................................... Descriptive Questions 1. Answer the following questions in depth: a. What is computer memory? b. What do you mean by storage location? c. What is register memory? What is its function? d. What is primary memory? e. Differentiate between SRAM and DRAM. f. What is ROM? g. What is the principle of being the name of the ROM? h. What is secondary memory? i. What is magnetic memory? j. What do you mean by magnetic disk? k. What is hard disk? l. What is SSD? m. What do you mean by optical memory? Logic based Questions 1. Answer the following questions logically: a. How does cache memory speed up the performance of the CPU? b. Why is RAM faster than secondary memory? c. Why does computer need backup of power supply? d. Why is the performance slower of DRAM compared to SRAM? e. Why is ROM essential in the computer? f. Why is secondary memory called non-volatile? g. Why is hard disk called hard drive? h. Why is SSD more efficient than HHD? i. Why is pen drive popular storage device? j. How does hard disk read and write the data? k. Why are optical disks used? Smart Computer Science Book-9 67

Application Case Studybased questions 1. When Tiya is started her computer, she got such information as shown in the picture. a. Which program helps to start up her computer? Where is it stored? b. What is going on in the picture? c. Where was this Windows program stored in the computer? d. Where is this windows program being stored? 2. Stream Nepal Musical Film Pvt. Ltd. is record- ing a music video 'Sadain rati spanama ....' sing by Devi Gurung. a. During the recording of the song, where does it store? b. After recording, where do they store the song for further processing in the computer? c. The music video editor Hikmat Chauddhay wants to take the intermediate edited file form official computer to home computer to complete the editing task, Which device would be used by him? d. To distribute this music video in the market, which storage device would be convenient for the company? Mention your strong logic. 3. Gorke and Gorki are doing their computer project work in the computer. When typing computer switched off due to load shedding problem. When they switch on the computer after getting power, they found some of the work is lost and they were able to get some part of the work. a. Why is some of the work is lost? State your logic. b. How were they able to get some part of the work? c. What should have been done by them to not get the work lost? d. They don't have a printer at home, they have to take the project work outside to print. How do they take it to print? e. After completing the project work they have to submit the hard copy as well as soft copy in the school. How would they submit the soft copy? Mention your strong logic. 68 Computer Memory

4. Saru Chamling is a tourist photographer. She captures new photos of different types of nature. a. When she clicks the photo, where does it store in her camera? b. How will she transfer photos from her camera to a computer for further processing? 5. Ganga Ram is going to establish a graphic design office. He has to buy two computers, one is very fast access to design the heavy work and run the heavy graphics design as well as video editing software. Another is for light work such as just typing the text and store data. For these two computers, which types of storage disk would you suggest to Gangaram? 6. Pandit Matrika Prasad told his children about playing a tape recorder for listening songs in his age. Which storage device was used by Pandit Matrika to play songs in his tape recorder? 7. Muskan Passa is a driver. He is interested to listen songs while driving, but he doesn't have any idea about it. Since he asked his son to solve his problem that he could listen song. How would his son suggest his father Muskan Pasa? Jitini Yadab 8. Look at the picture, Jitini Yadab typed some Class-9 information about her. Now, how much memory space is required by the computer to store this Jitini's information? Space bar and symbols needs 8 bits each of memory cell. Smart Computer Science Book-9 69

Activities 1. Organize an inter class speech competition on the topic \"Memory of the computer\" 2. Organize a chart paper presentation about \"HHD.\" 3. Write an article for your school's news bulletin on School Bulletin the topic \"SSD is going to replace HDD\" 4. Organize a debate competition in the topic of \"Role of Primary Memory is more important than Secondary Memory.\" 70 Computer Memory

Lab Activities 1. Perform the following activities in the Computer Lab with the supervision of computer teacher, then prepare the ac- tivities report. c. Get old unused Hard disk and dismantle and rec- ognized the inner parts of the hard disk. c. Fix all the parts of Hard disk. 2. Watch the YouTube Video in the following topics: a. Deassembled and assembled the HDD. b. HDD Defragmentation and working principal c. Principle of RAM memory d. Principle of Cache Work Project Work 1. Prepare the depth project work in any one of the following the topics: a. Secondary Storage b. Primary Memory The project work includes the following: a. Text b. Image c. Illustration figure d. Videos clip e. Digital Presentation Smart Computer Science Book-9 71

Computer Software CHAPTER 5 Chapter Includes • Introduction of Software • Introduction of Software • System Software and its types • System Software and its types • System development Software • Application Software and its types INTRODUCTION As we know, computer does not work itself, it needs our step by step instruction to perform the task. Since such instructions are written to instruct the computer as a computer program which is commonly known as computer software. Software is a collection of programs or apps which is designed to perform a well- defined function. A program or app is a sequence of instructions written to solve a particular problem. It directs all the peripheral devices on the computer system what to do, when to do and how to do a task. It brings life to the computer, without software, even the computer can not be started up. So, software is a soul of the computer. The software can be of three types: i) System software ii) Application software SYSTEM SOFTWARE The system software is a collection of programs designed to operate, control, and extend the processing capabilities of the computer itself. System software is generally prepared by the system programmers. These software include such programs written in low-level languages, which interact with the hardware at a very basic level. System software serves as the interface between the hardware and the end users. The common functions of system software are: i) Manage hardware devices and their functions such as input, output, processing and storage. ii) Manage files folder and other application and programming software. iii) Create operating platform. iv) Perform a language translation 72 Computer Software

v) Perform the maintenance tasks. The system software is classified into two types in the basis of its functionality: i. System Management Software ii) System Development Software SYSTEM MANAGEMENT SOFTWARE The software which is responsible to manage the computer system and make computer ready to work is called system management software. It includes start up the computer, create an operating platform to run the other programs and manage the overall function of hardware devices like input/output, process and storage task management. The common system management software are: i) Operating System ii) Device Drivers iii) Utility Software Operating System An operating system is the system software that works as an interface to enable the user to communicate with the computer. It manages and coordinates the functioning of peripheral devices and other software and make the computer ready to work. Every computer must have an OS(Operating System) to run the computer. Without an operating system, it won't create the working environment in the computer. The commonly used operating systems are Microsoft Windows, Linux, and Apple Mac OS X. Device Drivers Software A device driver is a system management software. It is a group of files that enables one or more hardware devices to communicate with the computer's operating system. These are not independent software, always assisted with the operating system for proper functioning. Without drivers, the computer would not be able to send and receive data correctly to hardware devices, such as a printer, scanner, USB devices, etc. System Utility Software A utility software is computer system software which is designed to analyze, configure, monitor, or help to maintain and keep a computer system up to date. Using utility we can perform formatting hard disk, taking backup files, virus protection, reduce the file size, defragment the disk etc. So, Smart Computer Science Book-9 73

it also called housekeeping software. Usually, a utility is smaller than a standard program in size and may be included with an operating system or installed separately. WinZip, WinRAR, Register cleaner, Antivirus software are examples of utility software. SYSTEM DEVELOPMENT SOFTWARE Systems development is the process of defining, designing, testing and implementing a new software application or program. So, the software which is used to perform such task is known as the system development software or programming software. The system development software includes appropriate programming language and language processor. Programming Language A programming language is a computer language which is used in computer programming to develop software or programs to execute. Most programming languages consist of instructions which are used in the program to instruct the computer as we like. In the basis of these collected instruction, computer works for us. The programming languages are categorized into three types: machine level language, assembly language and high level language. Nowadays high level programming language is more popular for programming. Examples of high level programming languages are QBASIC, Java, C, C++, Python, etc. Language processor A computer understands instructions in machine code, i.e. in the form of 0s and 1s. It is a tedious task to write a computer program directly in machine code. The programs are written in high level language or assembly language are called source code. Such source code cannot be executed directly by the computer and must be converted into machine language code. Hence, a special translator system software is used to translate the source code into machine code and vice- versa is called language processor. The language processors are three types: i) Assembler ii) Interpreter iii) Compiler Assembler : The Assembler is used to translate the program written in assembly language into machine code. The source program is an input of assembler that contains assembly language instructions. The output generated by assembler is the object code or machine code understandable by the computer. Source Code Assembler Object Code 74 Computer Software

Interpreter : Interpreter is a language translator makes translation of single statement of source program into machine code and executes it immediately before moving on to the next line. If there is an error in the statement, the interpreter terminates its translating process at that statement and displays an error message. The interpreter moves on to the next line for execution only after removing the error. An Interpreter directly executes instructions written in a programming or scripting language without previously converting them to an object code or machine code. Perl, Python, QBASIC has the such type of translator. Compiler : The language processor that reads the complete source program written in high level language and translates whole program it into an equivalent machine coded program is called a Compiler. We get such translator in C, C++, C#, Java. In a compiler, the source code is translated to object code successfully if it is free of errors. If there are any errors in the source code, the compiler specifies the errors at the end of compilation with line numbers. The errors must be removed before the compiler can successfully recompile the source code again. Object Code APPLICATION SOFTWARE The software which is capable of dealing with user inputs and helps the user to complete the task is called application software. It is also called end-user program or App because they enable the user to complete tasks, such as creating documents, spreadsheets, databases and publications, doing online research, sending e-mail, designing graphics, running businesses, and even playing games. The end user uses applications software for a specific purpose. It is programmed for simple as well as complex tasks, as a simple calculator application or complex word processing application. It can be either installed or accessed online. It can be a single program or a group of small programs that refers to an application suite. Some examples of application software are word processing software, Smart Computer Science Book-9 75

spreadsheet software, presentation software, graphics software, educational software, business software, entertainment software, etc. The application software is classified into two types: i) Packaged software ii) Customized or tailored software Packaged Software The software which is designed to meet the requirement of common varieties of users in different working fields is called packaged software. So, it is a generalized set of programs. It performs the common specific task and it's used in a wide range . MS-Word, Ms-Excel, PowerPoint, Photoshop, etc are examples of packaged software. Such types of software are used in different fields for common purposes. For example, MS-Word can be used in schools, hospitals, airlines, general offices, government offices for the word processing task. There are different types of packaged software, some examples of packaged software are Word processing,Graphic design, Video editing software, Spreadsheet software, etc. Customized or Tailored Software The software which is designed to meet the requirement for a specific group of users within an organization is called customized or tailored software. So, it is a specialized software, such custom software is designed to address the specific individuals or organization's needs precisely. It is more expensive than packaged software. Result processing software, telephone bill processing software, electricity bill processing software, are good examples of customized software, because such software cannot be used in other fields. For example, result processing software cannot be used in hospital, airlines, telephone office because it is specially designed for an academic organization. OPEN SOURCE SOFTWARE Open-source software (OSS) is software that is distributed with source code that may be read or modified by users. The OSS community generally agrees that open-source software should meet the following criteria: The program must be freely distributed. • Source code must be included with the program • Anyone must be able to modify the source code • Modified versions of the source code may be redistributed • As well, an open-source software license must not require the exclusion of, or interfere with, the operation of other software. 76 Computer Software

Points to Know • Software is a collection of programs or apps which is designed to perform a well-defined function. • The system software is a collection of programs designed to operate, control, and extend the processing capabilities of the computer itself. • The software which is responsible to manage the computer system and make computer ready to work is called system management software. • An operating system is the system software that works as an interface to enable the user to communicate with the computer. • A device driver is a system management software that enables one or more hardware devices to communicate with the computer's operating system. • A utility software is computer system software which is designed to analyze, configure, monitor, or help to maintain and keep a computer system up to date. • System development is the process of defining, designing, testing and implementing a new software application or program which includes programming language and language processor. • A programming language is a computer language which is used in computer programming to develop software programs. • A special translator system software which is used to translate the program written in high-level language into machine code and vice-versa is called language processor. It includes assembler, interpreter and compiler. • The software which is capable of dealing with user inputs and helps the user to complete the task is called application software. It includes package software and customized software. Terms to Know Interface : A point where two systems meet and interact. Source code : A text listing of commands prepared in the programming language. Object code : Code produced by a compiler or assembler. High level language : Programming language that enables to write a program in user friendly language like English language. Assembly language : A programming language that consists of instructions that are mnemonic codes for corresponding machine language instructions. Machine language Computer programming language consisting of binary 0s and 1s instructions which a computer can respond to directly. Database : Collection of information that is organized so that it can be easily accessed, managed and updated. Smart Computer Science Book-9 77

Worksheet Objective Questions 1. Fill in the blanks: a. Computer needs our step by step ........................ to perform the task. b. Software is a collection of ................................... c. System software is prepared by the ........................................... d. .............................. software is used to perform the maintenance task. e. A computer can understand instructions in .................................. code. f. Programming language is used to develop ................................. g. The programming language is categorized into ..................... types. h. ......................... makes translation of single statement of the source program. i. ............................. translates whole source program it into an equivalent machine coded program. j. Software can be either installed or accessed online. k. ........................... software is designed to address the specific individuals or organization's needs. 2. Write 'T' for true and 'F' for false statements: a. A program is a sequence of instructions. b. System software serves as the interface between hardware and end users. c. Every computer must have operating system software. d. Device drivers are dependent with the operating system. e. Nowadays assembly language is more popular for programming. f. Machine level language is understood by the computer directly. g. The program written in assembly language need not to be translated into machine code. h. The interpreter moves on to the next line for execution without removing the errors. 78 Computer Software

i. The compiler specifies the errors at the end of compilation with line numbers. j. The errors most be removed before the compiler can successfully recompile the source code again. 3. Circle for the correct option: a. Types of software: ii) Application software i) System Software iv) None of these iii) Both i) & ii) b. System management software: i) Operating system ii) Word processing iii) Spreadsheet iv) Compiler c. Operating system software: i) Linux ii) WinZip iii) WinRar iv) All of these d. Utility software are : i) Antivirus ii) WinZip iii) WinRar iv) All of these e. QBASIC is a : ii) Assembly language i) High level language iv) None of these iii) Machine level language f. Interpreter is a: ii) System software i) Language processor iv) All of these iii) Utility software g. Assembler is a: ii) Language processor i) Compiler iv) None of these iii) System software h. We get compiler with : i) C++ ii) C# iii) Both i) and ii) iv) Perl i. QBASIC has : i) Compiler ii) Interpreter iii) Assembler iv) All of these j. Microsoft Windows is a : ii) Utility software i) System software iv) None of these iii) Application software Smart Computer Science Book-9 79

4. Match the following: Language processor a. Interpreter Utility software b. WinZip Operating system c. Apple Mac OS X Programming language d. Java Package software e. Photoshop Result processing software f. Tailored software 0's and 1's g. Machine code App h. Application software Interpreter i. Python Compiler j. C Concentric circle k. Cache memory 5. Write the terms for the following: e. The code obtained by the assembler. a. Software which enables to complete their task. Ans:......................................... Ans:......................................... f. The language which is used to b. Software which is used in different write instructions in 0's and 1's. fields for a common purpose. Ans:......................................... Ans:......................................... c. The software which is used to g. The code obtained by the perform as housekeeping task. compiler. Ans:......................................... Ans:......................................... d. The software which is designed to h. Process of defining, designing, meet the requirement for a specific testing and implementing a group of users. new software application. Ans:......................................... Ans:......................................... 80 Computer Software

Descriptive Questions 1. Answer the following questions in depth: a. What do you mean by software? b. What is system software? Write the common functions of system software. c. What is system management software? d. What is operating system? e. What is device driver software? f. What do you mean by system development software? g. What is programming language? h. What do you mean by assembler? i. Differentiate between interpreter and compiler. j. What is application software? Logic based Questions 1. Answer the following questions logically: a. Why is software called soul of the computer? b. Why every computer must have an operating system? c. Why is utility software called housekeeping software? d. Why is language processor needed? e. Why is application software called end user program? f. Why is package software called generalized software? g. Why is customized software called specialized software? Application Case Study based questions 1. Rohit Chaudhary wants to send a file of 20 MB as an attachment using e-mail. The uploading process consumes too much time. a. What can Rohit do to reduce the file size and speed up the process? b. Name the program required for this case and the software category? 2. Muma Tamang is feeling slow performance of her computer. a. What can Muna do in this case? b. Which software is required for this case and name the category of the software ? 3. Dhana Saru has been assigned a task by his computer teacher to write a computer program. a. Which software is required by Bhurka for this task and name the category of the software. Smart Computer Science Book-9 81

b. Can computer understand his written program directly? Give you logical solution. Activities 1. Organize an inter class speech competition on the topic \"Customized software is more expensive than package software.\" 2. Organize the chart paper presentation about \"Programming Language\" 3. Write an article for your school's news bulletin in School Bulletin the topic \"Operating system\" 4. Organize a debate competition in the topic of \"Software is more important than Hardware.\" 82 Computer Software

Lab Activities 1. Perform the following activities in the computer Lab with the supervision of computer teacher, then prepare the ac- tivities report. a. Find the software used in your computer lab and list out them in the basis of following title: • Operating system • Package software • Utility software • Tailored software • Programming language 2. Watch the given video in the following topic. a. Why is the binary number system used in computer? b. Working principle of Assembler, interpreter and com- piler. Project Work 1. Prepare the depth project work in the following the topic: Computer Software The project work based on the activities report you pre- pared in the above activities. The project work includes the following: a. Text b. Image c. Illustration figure d. Videos clip e. Digital Presentation Smart Computer Science Book-9 83

Operating System CHAPTER 6 Chapter Includes • Introduction of Operating System • Introduction of Windows operat- • Functions of Operating System ing system. • Types of operating System • Files and Folder Management • GUI Environment. INTRODUCTION An operating system (OS) is the software component of a computer system that is responsible for the management and coordination of activities and sharing of the resources of the computer. The commonly required resources are input/ output devices, memory, file storage space, CPU (Central Processing Unit) etc. The operating system acts as a manager of these resources and allocates them to specific programs and users, whenever necessary to perform a particular task. Therefore, operating system is the resource manager which manage the resource of a computer system internally. In simple terms, an operating system is the interface between the user and the machine. Every computer must have at least one OS to run the computer. Without operating system, it won't create the working environment in the computer. It brings life to the computer system, then computer becomes ready to work. When we switch on the computer, the operating system is loaded in the main memory from secondary storage. The commonly used operating systems are Microsoft Windows, Linux, and Apple Mac OS X. FUNCTION OF AN OPERATING SYSTEM An operating system software performs each of the function: Process management: Process management helps OS to create and delete processes. It also provides mechanisms for synchronization and communication among processes. Memory management: Memory management module performs the task of allocation and de-allocation of memory space to programs in need of this resources. File management: It manages all the file-related activities such as organization storage, retrieval, naming, sharing, and protection of files. 84 Operating System

Device Management: Device management keeps tracks of all devices. This device management task is known as the I/O controller. It also performs the task of allocation and de-allocation of the devices. I/O System Management: One of the main objective of any OS is to hide the peculiarities of that hardware devices from the user. Secondary-Storage Management: Systems have several levels of storage, which includes primary storage, secondary storage, and cache storage. Instructions and data must be stored in primary storage or cache so that a running program can reference it. Security: Security module protects the data and information of a computer system against malware threat and authorized access. Command interpretation: This module is interpreting commands given by the and acting system resources to process that commands. Networking: A distributed system is a group of processors which do not share memory, hardware devices, or a clock. The processors communicate with one another through the network. Job accounting: Keeping track of time & resource used by various jobs and users. Communicationmanagement: Coordination and assignment of compilers, interpreters, and other software resource of the various users of the computer systems. TYPES OF OPERATING SYSTEM There are various types of operating systems, and single user and multiuser operating systems are two of them. In a single user operating system, only one user can access the system at a time. On the other hand, in a multiuser operating system, multiple users can access the system simultaneously. Single User Operating System In a single user operating system, a single user can access the computer system at a time. These types of operating systems are commonly found in home computers. There are two types of single user operating systems called single user, single task operating system and single user, multi-task operating system. In the single user, single task operating system, single user can perform only one task at a time. Palm OS for Palm handheld computers is an example for a single user, single task operating system. In a single user multitask system, a single user can perform multiple tasks at the same time. Microsoft Windows and Apple Mac OS allow a single user to work on multiple programs at the same time. For Smart Computer Science Book-9 85

example, a user can work on a word document and browse the WWW (World Wide Web) simultaneously. Most modern personal computers and laptops have single user multi-tasking operating systems. Multiuser Operating System A multiuser operating system allows multiple users to access the computer at the same time. The operating system manages the memory and resources among the various users according to the requirements. The task of one user will not affect the tasks of the other users. UNIX and Linux are examples of multiuser operating systems. WINDOWS OPERATING SYSTEM MS Windows is a multitasking operating system which uses a Graphical User Interface (GUI) to link the user to the computer. A GUI is an interface that helps users to interact with the computer by use of windows, icons, and menus. The interaction between the user and the computer heavily relies on the use of a mouse and keyboard which make it possible to enter data into the computer and also manipulate it the way we want. Components of Windows GUI Environment Icons DESKTOP Task Bar Desktop The desktop is the primary user interface of a computer. When you boot up your computer, the desktop is displayed once the startup process is complete. It includes the desktop background (or wallpaper), icons of files, folders and 86 Operating System

shortcut you may have saved to the desktop. In Windows, the desktop includes a task bar, which is located at the bottom of the screen by default. Icons An icon is a small graphical representation of a program or file. When you double- click an icon, the associated file or program will be opened. Icons are a component of GUI operating systems, including Apple macOS X and Microsoft Windows. Icons help users quickly identify the type of file represented by the icon. Taskbar The taskbar is an element of an operating system located at the bottom of the screen. It allows you to locate and launch programs through Start and the Start menu, or view any program that is currently open. Window A window is a separate viewing rectangular area on a computer display screen that allows multiple viewing areas. There are two types of window: i) Application Window ii) Document window. Title Bar Menu Bar Minimize, Maximize & Close Buttons (Windows Control Buttons) Vertical Scroll Bar Horizontal Status bar Resize Corner Scroll Bar Application Window: The application window is the one that is running your program. It can be opened, closed, resized and moved on the desktop. If MS- Smart Computer Science Book-9 87

Word, MS-Excel, PowerPoint, any program is running that has a own application window. Document Window : The smaller window, which is inside the Application window is called the document window. This window is used for typing, editing, drawing, and formatting the text and graphics. PARTS OF WINDOW Title Bar: The Title Bar is located at the top of the window. This bar shows the name of the Program or the window. The ‘Title Bar’ of ‘Calculator’ shows its name of the window which you can see 'Calculator'. Menu Bar: The Menu Bar is located just below the ‘Title Bar’. This menu has a number of options on it, such as File, Edit, Search etc. Whenever you click at any ‘Menu Pads’, a pull down menu opens up. Minimize button: It is used to minimize the window to a button on the ‘Taskbar’. If you click once on this button, a window will be minimized and transfer as a button on the ‘Task bar’. Maximize button: If the window is reduced, clicking on this button to increase the size of the window. If you click on this button, windows will be maximized and fit to the full screen. Restore button: When you maximize the window, the maximize button changes to ‘Restore button’. Clicking on the ‘Restore button’, it restores the ‘Paint window’ to its original size. If you click on this button, you will get the original size of the window. Close button: It is used to close the window. When you click on this button, ‘Paint window’ will be closed. Scroll Bars: The scroll bars help you to either move up or down in a window are known as vertical scroll bars. The scroll bars that help you to move either in the left or right side of the window are known as the ‘Horizontal Scroll Bars’. Status Bar: A status bar is a small area at the bottom of a window. It is used by some applications to display helpful information for the user. Resize Corner: Resize corners are known as the corner of bottom and top left- right corners which are used to increase or decrease the size of the Window proportionally. DAILOG BOX AND GUI CONTROLS A dialog box is a common type of window in the GUI of an operating system. It 88 Operating System

displays information, and asks a user for input. Basically, dialog box includes the following GUI controls: i) Buttons ii) Radio buttons iii) List Box iv) Combo Box v) Check Box vi) Text Box vii) Spin Buttons viii) Tab Buttons Check Box Spine Buttons Text Box Combo/List box Radio Buttons Buttons Tab Buttons MOUSE POINTER AND SHAPES A mouse cursor, also known as a mouse arrow, or mouse pointer, is a graphical image that is used to activate or control certain elements in a graphical user interface. In the basis of location, it changes the shapes of pointer. The following picture illustrates the shape and meaning of the mouse pointer. Smart Computer Science Book-9 89

MOUSE ACTION The basic actions of mouse are described in the given table: Mouse Action Description Pointing Place your mouse pointer over an object. Click Generally, pressing the primary (usually left mouse button) but- Double Click ton and releasing. Point to the item on the screen, and then click left mouse button Right Click twice quickly. Double-clicking is most often used to open items Dragging on your desktop. Point to the item on the screen, and then press and release the Scrolling secondary button (usually the right button). Point to the object on the screen, press and hold the primary button, move the object to a new location, and then release the primary button. To scroll down, roll the wheel backward (toward you). To scroll up, roll the wheel forward (away from you). 90 Operating System

FILES AND FOLDER MANAGEMENT A file is an item that contains information such as text , picture or music, video, etc. Files are represented by an icon that makes easy to recognize a type of file by looking at its icon. A folder is a container which is used to store files in it. You can create any number of folders and even store folders inside other folders are called sub folders. View the content of File/Folder To view the content of file/folder: Steps to Follow: Step-1 : Click any folder to see its contents. Step-2 : Double click on any file icon to view its contents. View the Computer Folder: A common reason to open the This Computer folder is to view the available space on your hard disks and removable media and access the Folder and files. To view the computer folder, do the following: Steps to Follow: Step-1 : Double Click the 'This PC / My Computer' icon; generally it is avail- able on the desk- top. Or Step-2 : Right mouse Click the 'This PC / My Computer' icon from the desktop. Step-3 : Click the 'Open' option of the context menu. Now, you get the window of Computer Folder as given. Creating a New Folder To create a new folder, follow the following steps: Smart Computer Science Book-9 91

Steps to Follow: Step-1 : Open the Location of the disk; where you want to create a folder. Step-2 : Right mouse click in the blank space of open location. You get a context menu. Step-3 : Select 'New' option. Step-4 : Select 'Folder' and click once. Step-5 : You get 'New folder'. Now, type your folder name and press Enter. Trick & TIP • A file or folder name can be given up to 255 characters long, includ- ing space. But, it can not contain any special characters such as / \\ : * ? < > etc. accept _ underscore. Copying File/Folder Copying a file/Folder refers to reproduce it in another location, without removing it from its original location. To copy a file/folder in new location, follow the following steps: Steps to Follow: Step-1 : Right mouse click on the folder and select 'Copy' option. Step-2 : Open your desired destination location to place file. Step-3 : Right mouse click on the open space. Step-4 : Select 'Paste' option. Step-5 : Now, you get a copy of file or folder in the new location. Moving File/Folder Moving a file or folder refers to shift it from its original location to another new 92 Operating System

location. To move file or folder, follow the following steps: Steps to Follow: Step-1 : Right mouse click on the folder and select 'Cut' option. Step-2 : Open your desired destination location to place file. Step-3 : Right mouse click on the open space. Step-4 : Select 'Paste' option. Now, you can notice that the file or folder is moved. Renaming a File/Folder To rename a file or folder, follow the following steps: Step-1 : Right mouse click on the folder. Step-2 : Select and click on the 'Rename' option from the context menu. Step 3 : Type the new name. Step 4 : Press ‘Enter’ key. Now, you will notice the name is changed. Deleting a File/Folder Deleting file/folder refers to remove file/folder permanently from the computer. To delete file/ folder, follow the following steps: Step-1 : Select the Folder to be deleted. Step-2 : Right mouse click the selected Folder. Step-3 : Click the 'Delete' option from the context menu. Fast Access Keys Combination Function Ctrl+C To copy selected file or folder. Ctrl+V To paste the copied item in the new location. Ctrl+x To cut the selected item. Del key To delete selected item. Shift+Del To delete file or folder permanently. Smart Computer Science Book-9 93

Trick & TIP • The deleted file/folder will be stored in the ‘Recycle Bin’ before being permanently removed from the hard disk. But if you delete from pen drive, it won't store on the recycle bin. • You can also delete a file or folder by dragging it to the Recycle Bin or by selecting the file or folder, and then pressing the Delete key. • You can select more than one file/folder by pressing the ‘Shift’ key and the left mouse button simultaneously. Lab Activities a. Create a folder with your name such as 'AMAN' on the desktop. b. Open your folder and create another folder naming 'PROJECT' inside it. c. Copy 'PROJECT' folder on the desktop. d. Move the folder having your name; inside the disk of D: Drive. e. Rename the folder 'PROJECT' to 'PROJECT WORK'. f. Delete your folder created with your name. g. Drag and drop folder 'PROJECT WORK' in the Recycle bin. Review Knowledge 1. Answer the following questions: a. Where do you find 'This Computer' icon folder? Why do you view it? Ans: ............................................................................................................................. ..................................................................................................................................... 94 Operating System

b. Why do you create a folder? Ans: ............................................................................................................................. ..................................................................................................................................... c. How do you select more than one file or folder? Ans: ............................................................................................................................. ..................................................................................................................................... d. What is the role of 'Paste' Command? Ans: ............................................................................................................................. ..................................................................................................................................... e. When do you use the delete command? Ans: ............................................................................................................................. ..................................................................................................................................... f. When do you use 'Cut' command ? Ans: ............................................................................................................................ ..................................................................................................................................... Finding Files and Folders If you forget the location of files and folders on the disk, Windows provides several ways to find them. To find the files or folders, follow the following steps: Steps to Follow: Step-1 : Type the part of the name in 'Search program and files' text box. Step-2 : Press 'Enter' key. Now, you get your possible list of files. Recycle Bin Recycle Bin is a folder which holds deleted files temporarily. When you delete a file from your computer, it will actually just move to the Recycle Bin and get stored until the Recycle bin is emptied. So, it is also called dust bin. This gives you an opportunity to recover accidentally deleted files and restore them to their original locations. Smart Computer Science Book-9 95

Restore Deleted File When you delete a file, it will usually move to the Recycle Bin so that you can restore the file later if it is necessary. To restore file, do the following: Steps to Follow: Step-1 : Find the 'Recycle Bin' on the desktop. Step-2 : Open the 'Recycle Bin' Win- dow. Step-3 : Select a file to be recovered. Step-4 : Click the 'Restore the select- ed item' option from the task bar. Now, your selected item is restored to its original location. Permanently Delete item from Recycle Bin Permanently deleting files from your computer and make free space of hard disk to use, you need to delete the files from the Recycle Bin. You can delete individual files from the Recycle Bin, or empty the entire Recycle Bin at once. Steps to Follow: Step-1 : Click to open Recycle Bin. Step-2 : Do one of the following: • To permanently delete one file, click it, press Delete, and then click Yes. • To delete all of the files, on the toolbar, click Empty the Recycle Bin, and then click Yes. Tricks & TIPS • You can empty the Recycle Bin without opening it by right-clicking the Recycle Bin and then clicking Empty Recycle Bin. • You can permanently delete a file from your computer without sending it to the Recycle Bin by clicking the file and then pressing Shift+Delete. 96 Operating System

Delete Temporary Files Temporary files created by Windows remain on the hard drive due to an irregular exit from a Windows session. But under normal conditions, when you quit a Windows session properly, these files are closed and deleted by Windows. Temporary files may cause slow down of the computer and fill up the disk space. To delete temporary file, do the following. Steps to Follow: Step-1 : Type 'Run' command in search text box. Step-2 : You get 'Run' dialog box. Step-3 : Type %temp% and click the 'Ok' button. Step-4 : You get all the temporary files in a list. Step-5 : Select all the files by pressing Ctrl+A keys combination. Step-6 : Press Del key from the keyboard. You get confirmation message. Step-7 : Press 'Yes' to confirm. Step-8 : You get the 'Recycling' the dialog box. After recycling, all the temporary files are stored in the 'Recycle Bin'. Changing the Wallpaper The background of the ‘Desktop’ is called the wallpaper. The steps to change the wallpaper: Steps to Follow: Step-1 : Right Mouse Click on the desktop. You get context menu. Step-2 : Select the 'Personalize' option. You get a dialog box. 97 Smart Computer Science Book-9

Step-3 : Select the desired picture. Step-4 : Finally, close the dialog box. Changing the Screensaver A screen saver is an animated image that is activated on a personal computer display when no user activity has been sensed for a certain time. The steps for changing the screensaver are: Steps to Follow: Step-1 : Right Mouse Click on the desktop. You get context menu. Step-2 : Select the 'Personalize' option. You get a dialog box. 98 Operating System

Step-3 : Click the Lock Screen. Step-4 : Scroll down from the dialog box and Click the 'Screen Saver Setting'. You get the screen saver setting dialog box. Step-5 : Set the appropriate parameters from the dialog box. Step-6 : Click the 'Apply' button. Step-7 : Click the 'Ok' button. Trick & TIP • The screensaver starts if your computer is idle for the number of minutes speci- fied in the ‘wait’ box. • To stop the screensaver, move the mouse pointer or press any key from the key- board. Lab Activities a. Create three folders as 'MY SONGS', 'MY MOVIES' and 'MY PROJECT WORK'. b. Search these folders using the searching key word 'MY'. Now, these files are listed or not in the searched list. c. Delete 'MY SONGS' folder and check the Recycle Bin; whether deleted folder is found or not. d. Restore this 'MY SONGS' folder from the Recycle Bin and make sure whether it is restored or not in the original location. e. Delete 'MY PROJECT WORK' and 'MY MOVIES' Folder. f. Now, permanently delete 'MY PROJECT WORK' and restore 'MY MOVIES' folder. g. Delete remain folders 'MY MOVIES' and 'MY SONGS'. h. Check the Recycle Bin and restore the necessary items, then make empty it. i. Display temporary files of your computer then delete them permanently. j. Set the screen saver as you like. k. Set the desktop wall paper as your interest. Smart Computer Science Book-9 99

Review Knowledge 1. Answer the following questions: a. You forget the location of disk where you had stored your file. Now, to solve this problem, what should you do? Ans: ............................................................................................................................ ..................................................................................................................................... b. If you deleted your file or folder accidentally; which is very important. Now, is there any technique to recover it? Ans: ............................................................................................................................ ..................................................................................................................................... c. In how many ways can you delete your file or folder permanently? Write these commands. Ans: ............................................................................................................................ ..................................................................................................................................... .................................................................................................................................... d. How are temporary files created? Ans: ............................................................................................................................ ..................................................................................................................................... e. When does screen saver activate? Ans: ............................................................................................................................ ..................................................................................................................................... f. When do you search your items in the computer? Ans: ............................................................................................................................ ..................................................................................................................................... 100 Operating System