Learning Objectives

1. Learning Objectives At the end of this class, you will be able to: Define hardware Tell what are output devices Tell what is CPU Tell what is UPS Identify Laptops and Tablets

2. Hardware Figure below shows the various hardware components of a computer and the way they interact with each other. Central Processing Unit output unit Input unit output Devices Input Devices Memory Unit Other devices

3. Input Devices These are use to enter data in a computer. Keyboard , mouse and scanner are some examples of input devices.

4. Input Devices Keyboard Information is typed on the keyboard. It converts the keystrokes into electrical signals that a computer can understand.

5. Input Devices Keyboard

6. Input Devices Mouse Movements of a mouse and displayed on the screen. Mouse offers clicking options to perform certain task.

7. Input Devices Mouse

8. Input Devices Joystick A joystick is a lever that moves in all directions and controls the movement of a pointer on the screen. A joystick pointer keeps scrolling till the joystick is brought back to the upright position. Most joysticks include two buttons called triggers. It is mostly used in computer games.

9. Input Devices Joystick

10. Input Devices Light pen A light pen is like a pen that has a light sensitive detector at its tip. You can select items by moving a light pen over a screen.

11. Input Devices Light pen

12. Input Devices Barcode reader A barcode reader is required to read the information given in the form of a barcode. It uses a beam of light to read a barcode. A digital circuit present inside converts the signal into meaningful data.

13. Input Devices Barcode reader

14. Input Devices Trackball It is similar to a mouse in which we move the ball with fingers or palm. It takes up less space than a mouse since it remains fixed. It has pointer options similar to a mouse.

15. Input Devices Trackball

16. Input Devices Scanner A scanner creates a picture file in a computer from a photograph or hard copy (paper document)

17. Input Devices Scanner

18. Input Devices Touch screen It is a type of screen that reads the user’s choice according to where it is touched. Touch screen is very convenient and consumes no extra space. But it can allow only limited type of operations. Touch screen terminals are used in public places, like railway stations, to provide information.

19. Input Devices Touch screen

20. Input Devices Touchpad It is type of pad with sensor detector. Touchpad can be operated by moving fingers on it. It also has buttons similar to a mouse.

21. Input Devices Touchpad

22. Hardware Figure below shows the various hardware components of a computer and the way they interact with each other. Central Processing Unit output unit Input unit output Devices Input Devices

23. Output Devices • The result obtained by the computer is • the output. • Output devices let you see the • work that you are doing. • They also allow you to hear sounds and • they provide you with hard copies of • your documents.

24. Output Devices Monitor It displays characters and graphics on a television-like screen. LCD CRT

25. Output Devices Monitor CRT A cathode-ray tube (CRT) monitor is a type of monitor that has a glass tube that is narrow at on end and opens to a flat screen at the other end. The shape of a monitor screen can be rectangular, circular or square shaped.

26. Output Devices Monitor LCD A liquid-crystals display (LCD) monitor is thinner, lighter, and less spacious than a CRT. One advantage of using it is that it consumes less energy conserving some electricity.

27. Output Devices

28. Output Devices Speakers Speakers are output devices that let you listen to sounds from your computer. They come in various sizes and colors and usually come in pair. Speakers function just like a stereo loudspeaker which you can adjust according to your desired volume.

29. Output Devices

30. Output Devices Printer Printer take text and pictures from a computer and print them on paper. Inkjet Printer Laser Printer Dot matrix Printer

31. Output Devices Dot matrix Printer It uses an inked ribbon against which striking pins make dots on paper. Different combinations of dots form different characters.

32. Output Devices How a dot matrix printer works? Inked ribbon Pins Ink dot

33. Output Devices Inkjet Printer The characters are printed by spraying ink on paper. It produces high quality text and graphics.

34. Output Devices Print head How an ink jet printer works? Ink droplets Print media Finished printed image

35. Output Devices Laser Printer It uses laser beams to produce printouts of high quality. Laser printers are very fast and can handle huge amount of printing. They are costlier than the other types of printers.

36. Output Devices How a laser printer works? Paper is fed into the machine. The printer’s processor decodes output data from the computer. Instructions from the printer’s processor turns a laser beam rapidly on and off. The paper is fed through the fusing unit where the toner is permanently abound to the paper by heat and pressure. The paper is discharged out of the machine.

37. Output Devices

38. Output Devices Headphones These output devices let only the user alone to listen to the sound of the computer. These are connected to a band designed to be placed over the listeners’ ears. Today’s headphones are designed light and bulky.

39. Output Devices

40. Hardware Figure below shows the various hardware components of a computer and the way they interact with each other. Central Processing Unit output unit Input unit output Devices Input Devices

41. Central Processing Unit • Central Processing Unit commonly known as the CPU, is the brain of the computer. It is the CPU that performs all the functions of the computer. • The CPU is a part of the computer system that processes the input data. • It also reads and executes instruction that you have given. • The CPU controls the functions of all the components attached to it. • The computer memory is found in the CPU

42. Central Processing Unit A CPU is made of Memory Unit The memory unit stores the data and instructions temporarily for processing. Control Unit The control unit controls the working of all parts of the computer based on the instructions received from the input devices. Arithmetic logic Unit (ALU) The ALU performs all the mathematical operations like addition, subtraction, multiplication and division as well as logical operations like comparison (<,>,=).

43. MEMORY Computers have the capability to store huge amount of data. The storage is done in hardware component called the memory unit. In memory unit, computer uses bits to store data. A bit is a binary digit, which can be either 0 or 1. A group of 8 bits is known as a byte. Computer memory is expressed in terms of bytes.

44. MEMORY 1024 bytes or 210 bytes = 1 kilobyte or KB 1024 KB or 220 bytes = 1 megabyte or MB 1024 MB or 230 bytes = 1 gigabyte or GB 1024 GB or 240 bytes = 1 terabyte or TB Memory is classified into primary and secondary.

45. MEMORY Primary memory It is used by the processor for storing data temporarily. Primary memory is also known as Random Access Memory (RAM). When a program is opened, it is loaded (copied) in RAM; once the program is closed, it is deleted from RAM. It is very fast and is also expensive. In most computer, the size of the primary memory is about 4 to 8 GB.

46. MEMORY RAM RAM stands for Random Access Memory. It is only a temporary memory. It stores data and instructions while the computer is turned on. When the computer is off, all the data stored in it is lost. RAM can pick out, or access, any piece of data from any point. So it is important to save your files before turning your PC off so that you can have it whenever you turn your PC back on.

47. MEMORY ROM ROM stands for Read Only Memory. Rom holds information that is built into it. Information stored on ROM cannot be modified or changed. You can only read the information from ROM.

48. MEMORY Secondary memory It is mainly used for storing user’s data/information for longer period of time. It is slower than primary memory and cheaper as well. Examples are hard disk, CD/DVD, floppy disk and flash memory device (pen drive). Most computers have hard disks with a capacity of 700 to 800 GB.

49. MEMORY Compact Discs A DVD is a storage device. It is a storage device that has the same diameter as a CD but have the capacity to contain much more data. It is originally known as the digital video disc but because of its many potential uses, it was renamed digital versatile disc. A CD can store up to 700MB of data, which is equivalent to 80 minutes of audio, hundreds of quality images, and a number of small video files.

50. MEMORY Floppy Discs A floppy disc is a storage device with a plastic casing. Inside it is a very thin piece of plastic coated with microscopic iron particles. The first 8 in floppy disc was developed by IBM in the late 1960s. It was invented by David Noble, an engineer of IBM. The first 3.5 in floppy discs was developed by Sony and was sold in 1981.