COMPUTER FUNDAMENTALS

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

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. Parts of the Computer System • Computer systems have four parts • Hardware • Software • Data • User • 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. Parts of the Computer System • 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. Parts of the Computer System • 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 • People operating the computer • Most important part • Tell the computer what to do • No system is completely autonomous

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

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. Essential Computer Hardware • Memory devices • Stores data or programs permanently or temporarily • Two most important types are: • Random Access Memory (RAM) • 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. 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. 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. 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. Software Runs The Machine • 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 • Network operating system (OS) • Utility

22. 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) • Allows computers to communicate and share data across a network • Windows Server 2003 • Utility • It is a program that makes computer system easier to use or perform highly specialized functions • Symantec AntiVirus

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

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. 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 2Interacting 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. 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. 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. 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. The Mouse • Optical mouse • Light shown onto mouse pad • Reflection determines speed and direction • Requires little maintenance

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. The Mouse • Benefits • Pointer positioning is fast • Menu interaction is easy • Users can draw electronically

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

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

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

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

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. Carpal Tunnel Syndrome

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. 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. 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 Devices for the Hand

49. 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 Devices for the hand

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