1. Instructor: Fatima Naseem Lecture # 02 fatima.naseem@uettaxila.edu.pk http://web.uettaxila.edu.pk/CMS/AUT2010/c pCFbs/index.asp COMPUTER FUNDAMENTALS

2. Chapter 1B Looking Inside the Computer System

3. Overview Parts of Computer System > > > Hardware > Software > > > Data > User Information Processing Cycle Essential Computer Hardware Processing Devices Memory Devices RAM ROM Input and Output Devices Storage Devices Magnetic Storage Optical Storage

4. 1B-4 Parts of the Computer System Computer systems have four parts Hardware Software Data User Hardware Hardware Mechanical devices in the computer Anything that can be touched Interconnected electronic devices used to control computer’s operations, input, output Referred to as device

6. 1B-6 Parts of the Computer System Software Software Set of instructions which make the computer work Tell the computer what to do Also called a program Thousands of programs exist Some to help computer perform its tasks and manage its resources, others to help users perform their tasks such as creating documents

7. 1B-7 Parts of the Computer System Data Data Pieces of information that by themselves do not make much sense Computer processes them in various ways, converting them to useful information Computer organize and present data Users Users People operating the computer Most important part Tell the computer what to do No system is completely autonomous

9. 1B-9 Information Processing Cycle Steps followed to process data A computer converts data into information by performing various operations on data according to some instructions from a program, displays results to user and stores them This is called Information Processing Cycle Following are the step, and each involves one or more specific components of computer Input Processing Output Storage optional

11. 1B-11 Essential Computer Hardware All Computers use the same basic hardware Hardware categorized into four types Processor Memory Input and Output Storage

13. 1B-13 Processing devices Process that converts raw data into useful information is called ‘Processing’ To perform this computer needs two components: Processor Memory Processor is Brain of the computer PC generally has one or more specialized chips called ‘Microprocessor’ These are slivers of silicon etched with many electronic circuits Carries out instructions from the program To process instructions computer passes electricity through these circuits

14. Processor is called CPU “Central Processing Unit” Microprocessor is plugged into computer’s motherboard “Motherboard” is rigid rectangular card containing circuitry connecting processor to other hardware It can be thought of as a master circuit board

15. 1B-15 Essential Computer Hardware Memory devices Stores data or programs permanently or temporarily Two most important types are: Random Access Memory (RAM) Random Access Memory (RAM) Read Only Memory (ROM) Read Only Memory (ROM)

16. Random Access Memory (RAM) Volatile Like an electronic scratch pad As the program is launched it is loaded into and run from memory Similarly when data is entered it is entered into memory Therefore it is called read/ write memory Made up of chips mounted on a circuit board Stores current data and programs More RAM results in a faster system Measured in Bytes

17. Read Only Memory (ROM) Permanent storage of programs even if computer is shut down Called ‘Non-Volatile’ memory Holds the computer boot directions Whenever computer starts it checks ROM for directions that help it start up and for info about hardware devices

18. 1B-18 Essential Computer Hardware Input and output devices Allows the user to interact Input devices accept data Keyboard, mouse Output devices deliver data Monitor, printer, speaker Some devices are input and output Touch screens Communication devices

19. 1B-19 Essential Computer Hardware Storage devices Hold data and programs permanently Different from RAM Magnetic storage Floppy and hard drive Uses a magnet to access data Optical storage CD and DVD drives Uses a laser to access data

20. 1B-20 Software Runs The Machine Tells the computer what to do A set of instructions that drive a computer to perform tasks is called a ‘Program’ When a computer uses a particular program it is said to be ‘running’ or ‘executing’ that program Two types System software Application software

21. 1B-21 Software Runs The Machine System software System software Any program that controls computer’s hardware or used to maintain it and run in an efficient way Most important software Three basic types Operating system Operating system Network operating system (OS) Network operating system (OS) Utility Utility

22. Operating system Operating system Tells computer how to use its own components Windows XP, Macintosh, Linux Essential for any computer as it acts as an interpreter between hardware, application programs and the user Network operating system (OS) Network operating system (OS) Allows computers to communicate and share data across a network Windows Server 2003 Utility Utility It is a program that makes computer system easier to use or perform highly specialized functions Symantec AntiVirus

23. 1B-23 Software Runs The Machine Application Software Application Software Accomplishes a specific task Most common type of software MS Word, power point, games Covers most common uses of computers

24. 1B-24 Computer data Fact with no meaning on its own Stored using the binary number system Computerized data is ‘digital’ Data can be organized into ‘files’ File is simply a set of data with a name File that user can open and use is often called a ‘document’ Programs can also be organized as files

25. 1B-25 Computer users Personal computers are specifically designed to work with human users Some people think of computers as intelligent devices but in sense no computer is completely autonomous Computer can take on various Roles Setup the system Install software Running programs Mange files Maintain the system

26. “Userless” computers Require no human interaction once they have been setup, programmed, installed and started up Examples might be many home appliances, security systems, communication systems Run with no user input Automated systems Typically controlled by operating systems

27. Any Questions ?

28. Chapter 2 Interacting with Your Computer

29. Chapter 2A Using the Keyboard And Mouse

30. Overview Of Input Devices Used to input data to computer If computer is brain, input devices are sensory organs Keyboard and Mouse Devices for Hand > Pens> Touch screens > Game controllers Optical Input Devices > Bar Code Readers> Image Scanners and OCRs Audio Visual Input Devices Microphones Other Audio Inputs (Musical Instruments) Video Inputs Digital Cameras

31. 3A-31 The Keyboard The most common input device Must be proficient with keyboard Skill is called keyboarding Has 100 keys app Each key sends different signal to CPU

32. Standard Keyboard Layout Alphanumeric Keys Modifier Keys Numeric Keypad Function Keys Cursor Movement Keys Special Purpose Keys

33. Standard Keyboard Layout

34. 3A-34 The Keyboard How keyboard works Keyboard controller detects a key press Places a code into part of its memory called keyboard buffer Controller sends code to the CPU through system software Code represents the key pressed Controller notifies the operating system Operating system responds Controller repeats the letter if held too long Setting for it is called ‘repeat rate’

35. 3A-35 The Mouse All modern computers have a variant Allows users to select objects Pointer moved by the mouse Pointer is an on screen object Mechanical mouse Has a rubber ball connected to rollers and sensors Sensors send signals to computer Rubber ball determines distance, direction and speed The ball often requires cleaning

36. 3A-36 The Mouse Optical mouse Light shown onto mouse pad Reflection determines speed and direction Requires little maintenance

37. 3A-37 The Mouse Interacting with a mouse Actions involve pointing to an object Clicking selects the object Clicking and holding drags the object Releasing an object is a drop Right clicking activates the shortcut menu Modern mice include a scroll wheel

38. 3A-38 The Mouse Benefits Pointer positioning is fast Menu interaction is easy Users can draw electronically

39. 3A-39 Variants of the Mouse Trackballs Upside down mouse Hand rests on the ball User moves the ball Uses little desk space

40. 3A-40 Variants of the Mouse Track pads Stationary pointing device Small plastic rectangle Finger moves across the pad Pointer moves with the pointer Popular on laptops

41. 3A-41 Variants of the Mouse Track point Little joystick on the keyboard Move pointer by moving the joystick

42. 3A-42 Ergonomics and Input Devices Ergonomics Study of human and tool interaction Concerned with physical interaction Attempts to improve safety and comfort

43. 3A-43 Ergonomics and Input Devices Repetitive Strain Injury (RSI) Caused by continuous misuse of the body Many professions suffer from RSI Carpal Tunnel Syndrome Carpal tunnel is a passage in the wrist Holds nerves and tendons Prolonged keyboarding swells tendons

44. 3A-44 Carpal Tunnel Syndrome

45. 3A-45 Ergonomics and Input Devices Office hardware suggestions Office chairs should have Adjustable armrests and height Armrests Lower back support Desks should have Have a keyboard tray Keep hands at keyboard height Place the monitor at eye level

46. 3A-46 Ergonomics and Input Devices Techniques to avoid RSI Sit up straight Have a padded wrist support Keep your arms straight Keyboard properly Take frequent breaks

47. Chapter 2B Inputting Data In Other Ways

48. 3B-48 Devices for the Hand Pen based input Pen based input Tablet PCs, PDA Pen used to write data Pen used as a pointer As a tapping device Handwriting recognition On screen keyboard Used for short notes taking, inputting signatures, delivering orders

49. 3B-49 Devices for the hand Touch Screens Touch Screens Sensors determine where finger points Sensors create an X,Y coordinate Usually presents a menu to users Found in cramped or dirty environments

50. 3B-50 Devices for the hand Game Controllers Game Controllers Enhances gaming experience Provide custom input to the game Modern controllers offer feedback Joystick Game pad

51. 3B-51 Optical Input Devices Allows the computer to see input Bar Code Readers Bar Code Readers Converts bar codes to numbers Computer find number in a database Works by reflecting light Amount of reflected light indicates number

52. 3B-52 Optical Input Devices Image Scanners Image Scanners Converts printed media into electronic Reflects light off of the image Sensors read the intensity Filters determine color depths

53. 3B-53 Optical input devices Optical Character Recognition (OCR) Optical Character Recognition (OCR) Converts scanned text into editable text Each letter is scanned Letters are compared to known letters Best match is entered into document Rarely 100% accurate

54. 3B-54 Audiovisual Input Devices Microphones Microphones A sound card is a device which translates analogue audio signals to digital (a process called digitizing) and vice versa Used to record speech Speech recognition “Understands” human speech Allows dictation or control of computer Matches spoken sound to known phonemes Enters best match into document

55. 3B-55 Audiovisual Input Devices Musical Instrument Digital Interface Musical Instrument Digital Interface MIDI Connects musical instruments to computer Digital recording or playback of music Musicians can produce professional results

56. 3B-56 Audiovisual Input Devices Video Input Video Input Uses PC video Camera Digitizes the image by breaking it into pixels Its color and other characteristics are stored as digital code Usually now Webcam is used Using Video capture cards other video devices can also be connected

57. 3B-57 Audiovisual Input Devices Digital cameras Digital cameras Captures images electronically No film is needed Image is stored as a JPG file Memory cards store the images Used in a variety of professions

58. Chapter 3B End of Chapter