1. Hardware

2. Basic Computer System Central Processing Unit Input Devices Output Devices Backing Storage Devices

3. Basic Computer System Processor Processor –to process data Memory Memory –RAM stores programs and data when in use –ROM stores essential programs and data permanently Input devices Input devices –a way of getting data into the computer Output devices Output devices –so the computer can show us what it has done Backing storage devices Backing storage devices –to store programs and data when not in use

4. Central Processing Unit Input Device Output Device Backing Storage memory processor

5. Memory Central Processing Unit Memory Processor RAMROM RAM is random access memory RAM memory is used to store the programs being run and the files being used. RAM memory is lost when power is switched off. ROM is read only memory ROM memory is fixed memory which is placed there by the manufacturer and is used to store programs which are involved in the running of the computer system. ROM memory is not lost when power is switched off.

6. Memory The memory is split up into memory locations which store the data. Each memory location is like a pigeon hole where the data will be stored as bits. Each memory location has its own memory address. The number of bits stored in each memory location is called the memory word size. This can be 16, 24 or 32 bits. This is also the number of bits that are transferred at a time between the memory and the processor. Processor Memory Central Processing Unit

7. Processor The processor has 3 parts ALU The Arithmetic And Logic Unit, as its name suggests carries out the calculations and decision making Control Unit The Control Unit is in charge of the flow of data and the order and timing of processing instructions Registers Registers are temporary memory locations within the processor which hold data and information while it is being processed. Processor Memory Central Processing Unit ALU Control Unit Registers

8. Central Processing Unit Processor Memory ALU Control Unit Registers RAMROM

9. Input Devices Computers are digital devices which work with numbers - binary numbers. Computers are digital devices which work with numbers - binary numbers. All information used by a computer is held as a pattern of ones and zeros. All information used by a computer is held as a pattern of ones and zeros. Input devices are used to change information we understand into data the computer can process - binary numbers. Input devices are used to change information we understand into data the computer can process - binary numbers.

10. Input KeyBoard

11. Input Keyboard

12. Input Concept Keyboard

13. Input Mouse

14. Input Touch Pad

15. Input Tracker Ball

16. Input Joystick

17. Input Devices Keyboard Keyboard Concept Keyboard Concept Keyboard Mouse Mouse Touch Pad Touch Pad Tracker Ball Tracker Ball Joystick Joystick

18. Input Graphics Tablet

19. Input Touch Sensitive Screen

20. Input Touch Screen

21. Input Digital Camera

22. Input Digital Video Camera

23. Input Web Camera

24. Input Microphone

25. Input Sound Card

26. Input Scanner

27. Input Hand Held Scanner

28. Input Devices Graphics Tablet Graphics Tablet Touch Sensitive Screen Touch Sensitive Screen Digital Camera Digital Camera Microphone Microphone Sound Card Sound Card Scanner Scanner

29. Input Bar Code

30. Input OMR

31. Input OCR

32. Input MICR

33. Input Punched Card

34. Input Punched Tape

35. Input Magnetic Stripe

36. Input Devices Bar Code Reader Bar Code Reader Optical Mark Reader Optical Mark Reader Optical Character Reader Optical Character Reader Magnetic Ink Character Reader Magnetic Ink Character Reader Punched Card Reader Punched Card Reader Punched Tape Reader Punched Tape Reader Magnetic Stripe Reader Magnetic Stripe Reader

37. Output Devices Computers are digital devices which work with numbers - binary numbers. Computers are digital devices which work with numbers - binary numbers. All information used by a computer is held as a pattern of ones and zeros. All information used by a computer is held as a pattern of ones and zeros. Output devices are used to change data the computer has processed - binary numbers into information we can understand. Output devices are used to change data the computer has processed - binary numbers into information we can understand.

38. Output Monitor

39. Output Cathode Ray Tube

40. Output Liquid Crystal Display

41. Output Thin Film Transistor

42. Output Graphics Card

43. Output Ink Jet Printer

45. Output Laser Printer

47. Output Drum Plotter

48. Output Flat Bed Plotter

49. Output Sound Card

50. Output Speakers

51. Output Headphones

52. Output Robot Arm

53. Output Devices Monitor Monitor –CRT cathode ray tube –LCD liquid crystal display –TFT thin film transistor Graphics Card Graphics Card Printer Printer –Ink Jet Printer –Laser Printer Plotter Plotter –Drum –Flat bed

54. Output Devices Sound Card Sound Card Speakers Speakers Headphones Headphones Robot Arm Robot Arm

55. Backing Storage Devices Computers are digital devices which work with numbers - binary numbers. Computers are digital devices which work with numbers - binary numbers. All information used by a computer is held as a pattern of ones and zeros. All information used by a computer is held as a pattern of ones and zeros. Backing storage devices are used to permanently store computer data - binary numbers. Backing storage devices are used to permanently store computer data - binary numbers.

56. Backing Storage Units Bit(binary digit)1 or 0 Bit(binary digit)1 or 0 Byte (by eight)8 bits Byte (by eight)8 bits Kilobyte (Kb)1024 bytes Kilobyte (Kb)1024 bytes almost a thousand bytes Megabyte (Mb)1024 kilobytes Megabyte (Mb)1024 kilobytes almost a million bytes Gigabyte (Gb)1024 megabytes Gigabyte (Gb)1024 megabytes almost a thousand, million bytes Terabyte (Tb)1024 gigabytes Terabyte (Tb)1024 gigabytes almost a million, million bytes

57. Backing Storage Units 10x10X10X10 = 10 4 = 10000 10x10X10X10 = 10 4 = 10000 This is a nice round number in decimal. This is a nice round number in decimal. It is easy for us to work with. It is easy for us to work with. 2x2x2x2x2x2x2x2x2x2= 2 10 = 1024 2x2x2x2x2x2x2x2x2x2= 2 10 = 1024 This is a nice round number in binary. This is a nice round number in binary. It is easy to arrange in a computer system. It is easy to arrange in a computer system.

58. Bits and Bytes We use binary to store: Numbers Numbers Text Text Graphics Graphics Video Video Sound Sound Programs Programs

59. Storing Numbers Numbers are converted to in binary. Numbers are converted to in binary. 1 Bin is 1 Dec 10 Bin is 2 Dec 1000 Bin is 8 Dec 1001 Bin is9 Dec 1111 Bin is15 Dec 11111111 Bin is255 Dec

60. Binary to Decimal BinaryDecimal 128 64 32 16 8 4 2 1 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 11 0 0 0 0 0 0 1 02 0 0 0 0 0 0 1 13 0 0 0 0 0 1 0 04 0 0 0 0 0 1 0 15 0 0 0 0 0 1 1 06 0 0 0 0 0 1 1 17

61. Integers These are whole numbers which have no decimal part. These are whole numbers which have no decimal part. They can be easily converted to binary numbers. They can be easily converted to binary numbers. 1 byte can only store numbers up to 255. 1 byte can only store numbers up to 255. The computer can perform calculations on integers very quickly and efficiently. The computer can perform calculations on integers very quickly and efficiently.

62. Storing Text Text is stored using a special set of codes called ASCII. Text is stored using a special set of codes called ASCII. American Standard Code for Information Interchange American Standard Code for Information Interchange Each symbol (letter, number etc) has its own unique code Each symbol (letter, number etc) has its own unique code a is 97, A is 65, ? is 63, 3 is 51 a is 97, A is 65, ? is 63, 3 is 51 One ASCII code is one byte long (eight bits). One ASCII code is one byte long (eight bits).

63. Storing Graphics Black and White graphics are stored using pixels (Picture Elements). Black and White graphics are stored using pixels (Picture Elements). The image to be stored is broken up into dots, each dot is a pixel. The image to be stored is broken up into dots, each dot is a pixel. The pixels are 1 for black and 0 for white. The pixels are 1 for black and 0 for white.

64. Calculating Image Storage A black and white graphic uses 1 bit to store each pixel A black and white graphic uses 1 bit to store each pixel If the image is 300 pixels by 200 pixels then it is stored using a total of 300 x 200 bits i.e. 60000 bits If the image is 300 pixels by 200 pixels then it is stored using a total of 300 x 200 bits i.e. 60000 bits Divide this by 8 to give the number of bytes Divide this by 8 to give the number of bytes –60000/8 = 7500 Divide this by 1024 to give the number of kilobytes Divide this by 1024 to give the number of kilobytes –7500/1024 = 7.324 Round up to ensure you have enough storage Round up to ensure you have enough storage –7.324 = 8 Kb

65. Storage Floppy Disc

68. Storage Magnetic Disc

70. Storage Magnetic Tape

73. Storage Smart Card

74. Storage CD ROM

76. Storage DVD

77. Storage USB Flash Drive

78. Backing Storage Devices Floppy Disc1.44Mb Floppy Disc1.44Mb Magnetic DiscSeveral Gb Magnetic DiscSeveral Gb Magnetic TapeSeveral Gb Magnetic TapeSeveral Gb Smart Card few Kb Smart Card few Kb Compact Disc 650 Mb Compact Disc 650 Mb –CD ROM CD R CD RW Digital Versatile Disc 4.2 Gb – 17 Gb Digital Versatile Disc 4.2 Gb – 17 Gb –DVD ROM DVD R DVD RW DVD RAM USB Flash Drive16 – 256 Mb USB Flash Drive16 – 256 Mb

79. Backing Storage Devices Magnetic Magnetic –Floppy Disc –Hard Disc –Tape Optical Optical –CDROM CDR CDRW –DVD DVD R DVD RW DVD RAM Flash Flash –USB drives

80. Hardware