CHAPTER-8 COMPONENTS OF COMPUTER SYSTEM CLASS 9 CBSE

IT IS A CHAPTER 8 OF INFORMATION TECHNOLOGY OF CLASS 9

1. UNIT –III : INFORMATION AND COMMUNICATION TECHNOLOGY SKILLS CHAPTER 8 COMPONENTS OF COMPUTER SYSTEM

2. BASIC COMPONENTS OF A COMPUTER SYSTEM BLOCK DIAGRAM

3. HARDWARE IN COMPUTER HARDWARE REFERS TO ALL THE PHYSICAL PARTS OF A COMPUTER,SUCH AS THE : CPU,MOTHERBOARD , MONITOR , OUSE,KEYBOARD ETC THE PHYSICAL COMPONENTS OF A COMPUTER THAT YOU TOUCH AND FEEL COMPRISE THE HARDWARE OF A COMPUTER .

4. IS PENDRIVE IS A HARDWARE?HOW CAN YOU DEFINE PENDRIVE IS A EXTERNAL HARDWARE. A USB flash drive is a data storage device that includes flash memory with an integrated USB interface, and it's also called a pen drive and thumb drive. An external hard drive is a hard disk storage product that emphasizes portability and realizes large-capacity data exchange between computers.

5. HARDWARE IS CLASSIFIED INTO 3 MAIN TYPES 1] INPUT DEVICE 2]OUTPUT DEVICE 3]CPU

6. INPUT DEVICES /UNIT A PIECE OF EQUIPMENT/HARDWARE WHICH HELPS US ENTER DATA INTO A COMPUTER. THESE ARE THE DEVICES THAT ARE USED TO PROVIDE INPUT TO THE COMPUTER. THESE DEVICES TRANSLATE THE USER’S LANGUAGE/COMMANDS INTO BINARY LANGUAGE WHICH IS NLY UNDERSTANDABLE BY COMPUTER. EXMAPLE: KEYBOARD,MOUSE,ETC

7. OUTPUT DEVICES A PIECE OF EQIPMENT /HARDWARE WHICH GIVES OUT THE RESULT OF THE ENTEREDINPUT,ONCE IT IS PROCESSED[ i.e CONVERTS DATA FROM MACHINE LANGUAGE TO A HUMAN-UNERSTANDABLE LANGUAGE] SOFTCOPY[RESULT ON DISPLAY] HARDCOPY[PRINTED ON SHEET] SOUND FILE[SPEAKER] EXAMPLE: MONITOR , PRINTER , PLOTTER,ETC

8. CENTRAL PROCESSING UNIT CPU IS THE MAIN PART OF COMPUTER HARDWAR THAT ACTUALLY PROCESSES DATA ,ACCORDING TO THE INSTRUCTION IT RECIVES. IT CONTROLS THE FLOW OF DATA BY DIRECTING THE DATA TO ENTR THE SYSTEM,PLACES THE DATA INTO ITS MEMORY,RETRIEVES THE SAME AS AND WHEN NEEDED AND DIRCTS THE OUTPUT OF DATA ACCORDING TO A SET OF STORED INSTRUCTIONS.

9. MICROPROCESSOR A MICROPROCESSOR IS ATYPE OF INTERGRATED CIRCUIT,BUILT ON A TINY PIECE OF SILICON . A MICROPROCESSOR CHIP CONTAINS MILLIONS OF TRASISTOR. TRANSISTORS WORK TOGETHER TO STORE AND MANIPULATE DATA SO THAT THE MICROPROSSER CAN PERFORM A WIDE VARIETY OF FUNCTIONS . THE SPEED OF A CPU IS DETERMINED BY THE NUMBER OF INSTRUCTIONS IT EXCUTES PER SECOND , WHICH IS MEASURED IN MEGHAHERTZ[MHZ] DUE TO TECHNOLOGICAL DEVOLOPMENT /ADVANCEMENTS ,CPU SPEED IS MEASURED IN GIGAHERTZ[GHz]

10. MEGHAHERTZ AND GIGAHERTZ In computing, megahertz refers to the clock speed of a central processing unit (CPU), which determines how many instructions a processor can execute per second. This is a unit of frequency that represents one billion cycles per second. It's often used to describe the processing speed of computer processors, the frequency of radio waves, and other high-frequency phenomena.

11. COMPONENTS OF COMPUTER There are three main components of a CPU: 1] ALU 2] CU 3] MU

12. ARTHEMETIC LOGIC UNIT It is the component of CPU. An arithmetic logic unit (ALU) is a key component of a computer’s central processor unit. The ALU performs all arithmetic and logic operations that must be performed on instruction words. The ALU is split into two parts in some microprocessor architectures: the AU and the LU. ALU conducts arithmetic and logic operations. It is a major component of the CPU in a computer system.

13. CONTROL UNIT A control unit, or CU, is circuitry within a computer’s processor that directs operations. It instructs the memory, logic unit, and both output and input devices of the computer on how to respond to the program’s instructions. CPUs and GPUs are examples of devices that use control units. Known as ‘ Central Nervous System’

14. A control unit receives data from the user and translates it into control signals that are subsequently delivered to the central processor. The processor of the computer then instructs the associated hardware on what operations to do. Because CPU architecture differs from manufacturer to manufacturer, the functions performed by a control unit in a computer are dependent on the CPU type. The following are some examples of devices requiring a control unit: CPUs or Central Processing Units GPUs or Graphics Processing Units https://www.vedantu.com/computer-science/memory-devices

15. MEMORY UNIT The memory unit is a component of a computer system. It is used to store data, instructions and information. Stores both data and instructions. Data and instructions can also be stored permanently in this unit so that they are available whenever required. When other computer units require information, this unit provides it. Internal storage unit, main memory, primary storage, and  Random Access Memory  are used to describe it (RAM). Its size has an impact on its speed, power, and capabilities. In a computer, there are two sorts of memories: primary memory and secondary memory.

16. The memory unit’s functions It holds all of the necessary data and instructions for processing. It keeps track of the processing’s interim results. Before the final results of processing are sent to an output device, it saves them. The main memory receives and transmits all inputs and outputs.

17. The difference between the primary memory and secondary memory are tabulated below. Internal memory External memory Internal memory is also known as primary storage or main memory. It is volatile in nature in case of RAM but ROM is non-volatile. It is used to store data temporarily (in case of RAM). Internal memory is a working memory. Examples are RAM and ROM. External memory is also known as secondary storage. It is non-volatile in nature. It is used to store data permanently. External memory is not a working memory. Examples are hard disk, CD, DVD, flash drive etc.  

18. HDD AND SSD HDD HDD stands for  Hard Disk Drive . HDD contains moving mechanical parts, like the arm. HDD has longer R/W time. HDD has higher latency. HDD supports fewer I/O operations per second. HDD is heavier in weight. HDD is larger in size. In HDD the data transfer is sequential. HDD is less reliable due to possibility of mechanical failure, like head crash and susceptibility to strong magnets. SSD SSD stands for  Solid State Drive . SSD does not contains, mechanical parts, only electronical parts like ICs. SSD has shorter R/W time.. SSD has lower latency. SSD supports more I/O operations per second. SSD is lighter in weight. SSD is more compact in size. In SSD the data transfer is random access. SSD is more reliable. SSD is costlier per unit storage. HDD SSD

19. HDD is cheaper per unit storage. HDD is older and more traditional. HDD can produce noise due to mechanical movements. The availability of HDD in a variety of capacities. It is more likely to breakdown after more uses because of the magnetic platters and moving mechanical parts. HDD drives are more established and traditional.  HDDs are more reliable for long-term storage. The data accessing speed is slower as compared to SSD. HDD has  fragmentation  that’s why The performance suffers because of fragmentation. HDDs are suitable for Extensive storage Long-term storage SSD is newer to use. SSD does not produces noise. The availability of SSD is limited in terms of variety of storage capacities as compared to HDD. It is less likely to breakdown as compared to HDD because of no moving parts. A more recent kind of storage drive is an SSD. SSDs are comparatively less reliable for long-term storage due to data leaks that can occur if kept unpowered for more than a year. The data accessing speed is much higher as compared to HDD. SSD does not have fragmentation. The performance does not suffer because of fragmentation. SSDs are suitable for Fast data retrieval  Laptop or desktop consume low power

20. Conclusion Both HDDs and SSDs have their advantages and disadvantages. HDDs are a more traditional and cost-effective option for storing large amounts of data, while SSDs offer faster performance, durability, and energy efficiency. The choice between HDD and SSD ultimately depends on the user’s specific needs and requirements, such as the amount of data they need to store, their budget, and the device they are using the storage device with.

21. REGISTER A register is the smallest element for data holding. It is built-in directly in a processor, and thus, the registers act as certain memory locations that a processor can directly access in a computer. An individual register can hold a very small amount of data (it might be around 32 to 64 bits in size), an instruction, the storage addresses of data, or any other form of data, such as individual characters and bit sequences. Examples: Program counter, Address register, Instruction register, Accumulator register, and many more.

22. TYPES OF REGISTORS These are classified as given below.    Accumulator:   This is the most frequently used register used to store data taken from memory. It is in different numbers in different microprocessors.    Memory Address Registers (MAR):   It holds the address of the location to be accessed from memory. MAR and MDR (Memory Data Register) together facilitate the communication of the CPU and the main memory.    Memory Data Registers (MDR):   It contains data to be written into or to be read out from the addressed location.   

23. General Purpose Registers:   These are numbered as R0, R1, R2….Rn-1, and used to store temporary data during any ongoing operation. Its content can be accessed by assembly programming. Modern CPU architectures tends to use more GPR so that register-to-register addressing can be used more, which is comparatively faster than other  addressing modes .   Program Counter (PC):   Program Counter (PC) is used to keep the track of execution of the program. It contains the memory address of the next instruction to be fetched. PC points to the address of the next instruction to be fetched from the main memory when the previous instruction has been successfully completed. Program Counter (PC) also functions to count the number of instructions. The incrementation of PC depends on the type of architecture being used. If we are using 32-bit architecture, the PC gets incremented by 4 every time to fetch the next instruction.  

24. Instruction Register (IR):   The IR holds the instruction which is just about to be executed. The instruction from PC is fetched and stored in IR. As soon as the instruction in placed in IR, the CPU starts executing the instruction and the PC points to the next instruction to be executed.   Condition code register ( CCR ) :  Condition code registers contain different flags that indicate the status of any operation

25. SOFTWARE Computer Software is a programming code executed on a computer processor. It is a set of programs that can do particular work of the user.  The software simply is a collection of documentation, instructions, and procedures that are capable of performing different tasks on a computer system. 

26. TYPES OF SOFTWARE 1] SYSTEM SOFTWARE 2]APPLICATION SOFTWARE

27. SYSTEM SOFTWARE AND APPLICATION SOFTEWARE SYSTEM SOFTWARE This acts as an interface between the system and the applications It is the platform that allows the various application software to run on the system It is an independent software. Once this is installed the computer will work Since a device cannot work without a system software, the user has to have it installed in their devices APPLICATION SOFTWARE This is designed directly from the user perspective   These are independent applications which can be download and installed in the system Each application has a specific purpose and thus is developed with high-level languages so that the purpose can be fulfilled

28. System Software is generally developed in low-level languages. This is so that the interaction between the software and hardware can be simplified and made more compatible Is working is more automated. Once a system is turned on, the system software starts working User action is required to start application software. These applications can only be work when the user commands the system to do soThey have minimum involvement in the processing and functioning of the computer device The application software can be installed as and when the user requires them

29. These are responsible for the working of the system The system software are installed at the time of installing the operating system. A computer device cannot work without its presence Example for System Software includes Android, Mac Operating system, MS Windows, etc. This is a dependent software. Applications can only be downloaded when the operating system is installed These are designed to be user interactive, thus the application software can be removed as and when required by the user Examples of Application Software includes Word Processor, games, media player, etc.

30. SYSTEM SOFTWARE 1] OPERATING SYSTEM An Operating System (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is the most important type of system software in a computer system. Examples of Operating Systems are Windows, Linux, Mac OS, etc.

31. 2] UTILITY SOFTWARE The utility software is system software that helps maintain the proper and smooth functioning of Computer system. It assists the OS to manage ,organize , maintain , and optimize the functioning of the computer system. Some utilities help you to avoid virus attack , take backup of your data , recovering data,etc EX: network utility , file manager, disk management, scanning , backup,compresion .

32. NETWORK UTILITY Network utilities analyze the computer’s network connectivity , configure network settings , check data transfer or log events https://www.indeed.com/career-advice/career-development/utility-software It also tests the speed , performance , monitors network traffic from the console , and tracks the bandwidth usage of a network.

33. FILE MANAGEMENT File management tools are utility software that manages files of the computer system. Since files are an important part of the system as all the data is stored in the files This software helps to browse search , arrange , find information and quick preview the files of the systems .

34. DISK MANAGEMENT Disk management help users to view and manage disk drives. It can be used to partition drives , format drives , assign drive letters , and much more

35. SCANNING The act of examining the computer system , drives , or files , for possible virus or malware attack is known as “scanning”. Antivirus utility does the scanning. The utility protect your computer against virus attacts .

36. BACKUP Storing a copy a data in another storage device , it can recover the data when accidentally deleted.

37. COMPRESSION It is process of shrinking the files to occupy less disk space. The files that are bigger in size need to be compressed while sending as an email attachment. They can’t be read directly , again they want to decompose to their original form before use. EX: 7zipM

38. LANGUAGE PROCESSORS Language Processor are software programs that convert high-level programming languages into machine code for computers to understanding . They include compiler , assembler , interpeter .

39. ASSEMBLER An assembler is a type of computer program that takes in basic instructions and converts them into a pattern of bits that the computer’s processors can use to perform basic operations.

40. INTERPRETER An interpreter receives the source code and then line by line ,translating each line of code to machine code and executing it before moving on to the next line.

41. COMPILER A compiler is a software that converts the source code to the object code . In other words , we can say that it converts the high-level language to binary language. It is necessary to perform this step to make the program executable. This is because the computer understands only binary language.

42. APPLICATION SOFTWARE An application is computer software developed specifically to aid a user to perform any specific tasks. A computing platform generally possesses a hardware architecture and a software framework that permits application software to operate, for example, the operating system and programming languages.

43. THE APPLICATION SOFTWARE IS CLASSIFIED INTO TWO TYPES GENERAL PURPOSE APPLICATION SOFTWARE SPECIAL PURPOSE APPLICATION SOFTWARE [CUSTOMIZED SOFTWARE] APLLICATION SOFTWARE

44. GENERAL PURPOSE APPLICATON SOFTWARE General-purpose software performs a large range of specific basic tasks. They fulfill all the general tasks that a person needs to perform on the system. There are numerous applications that a user needs to perform. Among them, some variety of applications that are frequently used comes under this category.

45. These can be in independent stand-alone versions or in bundles that make up application suites. Some examples of application suites can be WPS Office,  MS Office , Apache OpenOffice , etc. The general-purpose software is divided further as follows:

46. a) Word Processing Software This software contains the features to create, edit, delete, access, format, and customize text files. In addition, they have several features like thesauruses, Word Art, etc. to customize and make the files more attractive and useful. They have additional features for publishing, sending mails, etc. Furthermore, it basically helps to create reports, letters, newsletters, manuals, books, etc.                                      Microsoft Word Examples are MS-Word, WPS Writer, Open Office Writer, Word pad, etc.

47. b) Spreadsheets This software contains the data in the form of rows and columns. The intersection of a row and column is a cell. They store the data and have various formulas which in turn helps to analyze, calculate, and draw conclusions from data. The business and financial sectors use this software more often. They also contain additional features like graphs, charts, 3D graphs, tables, etc. for effective results. Report presentation is thus quite easy considering these results. Examples are MS_Excel , Google Sheets, LibreOffice Calc, etc.

48. c) Database Management Systems A database is a collection of related data or information in an organized form. A database management system is a tool that is used to store, search, extract, or delete information from a database. Moreover, we use them so that the operations which we perform on the database, are in an organized manner and safe. Some  database  management tools help in handling records on the system like phone numbers, mailing lists, catalogs, etc. Examples are MS Access, Filemaker , dBASE , etc. While some others help to manage large and complex databases. Examples are SQL, Oracle, etc.

49. d) Desktop Publishing Software They help in designing interactive animations and 3D images using texts and graphics. Moreover, this software has many tools that help the user to produce different and innovative animations and graphics. Their basic applications are logos, magazines, newspapers, business cards, etc. Examples are Adobe InDesign , QuarkExpress , etc.

50. e) Web Browsers Web Browser is a software which we use to access information on the web (World Wide Web). Browsers allow users to search for information, read files, watch videos, download images, etc. Examples are Google Chrome, Mozilla Firefox, Safari, Internet Explorer, etc.

51. f) Presentation Software This software helps the users to display their projects and information in the form of slides. Hence, the slideshow is the basic feature of presentation software. Besides, those other features are graphs, charts, adding audio, videos, transitions, etc. Examples are PowerPoint, Corel Presentations, etc.

52. g) Video Editing Software This software helps the user to edit the videos. They can add text, animations, sound, etc. as per their requirement. They also have features to merge, split, or change the speed of the videos. Therefore, they are useful in creating documentaries, advertisements, etc. Examples are Adobe Premiere, Pinnacle Studio, etc.

53. h) Games Games are one of the favorite software. They are used by almost all types of users. There is a large variety of games available ranging from puzzles and mysteries to real-world animation games. There are hundreds of features in this software. Hence, the programming of such software is also complex. Examples are FIFA Football, Minesweeper, etc.

54. 2. Customized Software Sometimes people give the order to create certain special software according to their own specific requirements. Programmers generally develop such software on special demands. This software excludes the extra features of application software. Therefore, only such features are present which the user actually requires for his purpose. This software is not available on the web. So, one cannot download or use them directly.

55. Moreover, once the programmer creates the software, he gives it to the client with certain terms and rights. Due to these features, we can also name this software as  tailor-made software . For example, a beauty salon’s owner needs software to keep track of the bookings. Further, he requires to fix appointments or keep track of his products, etc.

56. Difference Between Application Software and System Software System Software Application Software They are software that handles specific tasks. Moreover, they can be general-purpose or customized. Examples: MS-Word, PowerPoint, Google Chrome, etc. They help only in the internal working of the computer system. They can utility software, operating system, drivers, etc. Examples: Android, Microsoft Windows, Win RAR, etc.

57. STORAGE UNIT/MEMORY UNIT Memory Memory is basically a device that has the capacity to store information. Moreover, it is the most important component of a computer system as it cannot perform even simple tasks without it. Basically, the  computer memory  is of two types namely,  primary memory  (Random Access Memory (RAM) and Read Only Memory (ROM)) and  secondary storage  (CD, DVD, hard disk, etc). Let us study the random access memory in detail.

58. RAM https://www.intel.com/content/www/us/en/tech-tips-and-tricks/computer-ram.html#:~:text=RAM%20is%20a%20common%20computing,applications%20and%20open%20your%20files .

59. TYPES OF RAM 1) DRAM DRAM (dynamic random access memory) is a type of semiconductor memory that is typically used for the data or program code needed by a computer processor to function. Memory is made of  bits  of data or program code that are arranged in a two-dimensional grid. DRAM will store bits of data in what's called a storage or memory cell, consisting of a capacitor and a transistor. The storage cells are typically organized in a rectangular configuration.

60. 2) SRAM https://www.techtarget.com/whatis/definition/SRAM-static-random-access-memory

61. 3)SDRAM https://www.lenovo.com/in/en/glossary/sd-ram/#:~:text=Firstly%2C%20it%20provides%20faster%20data,%2Daccess%20memory%20(DRAM) .

62. 4) DDR https://www.geeksforgeeks.org/ddr-ram-full-form /

63. ROM https://www.hp.com/us-en/shop/tech-takes/ram-vs-rom#:~:text=What%20is%20ROM%3F,you%20turn%20off%20your%20computer .

64. TYPES OF ROM https://www.toppr.com/guides/computer-science/computer-fundamentals/primary-memory/rom-read-only-memory / https://www.geeksforgeeks.org/what-is-flash-memory /

65. CAHCE MEMORY geeksforgeeks.org/cache-memory-in-computer-organization /

66. EXTERNAL MEMORY OR SECONDARY STORAGE IT IS ALSO KNOWN AS AUXILIARY MEMORY . IT STORE THE HUGE DATA PERMENTALY ,UNTIL YOU DELETE . EXAMPLE: CD,DVD,HDD,SSD