Transcript View File - UET Taxila

COMPUTER
FUNDAMENTALS
Instructor: Fatima Naseem
Lecture # 02
[email protected]
http://web.uettaxila.edu.pk/CMS/AUT2010/c
pCFbs/index.asp
Chapter 1B
Looking Inside the Computer
System
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
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
1B-4
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
1B-6
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
1B-7
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
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Essential Computer Hardware
 All Computers use the same basic hardware
 Hardware categorized into four types
 Processor
 Memory
 Input and Output
 Storage
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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
1B-13
 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
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)
1B-15
Random Access Memory (RAM)
 Volatile
 Like an electronic scratch pad
 As the program is launched it is loaded into
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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
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
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
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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
1B-19
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
1B-20
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
1B-21
 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
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
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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
1B-24
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
1B-25
 “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
Any Questions ?
Chapter 2
Interacting with Your Computer
Chapter 2A
Using the Keyboard And
Mouse
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
> Game controllers
> Touch screens
 Optical Input Devices
> Bar Code Readers
> Image Scanners and OCRs
 Audio Visual Input Devices
 Microphones
 Other Audio Inputs (Musical Instruments)
 Video Inputs
 Digital Cameras
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
3A-31
Standard Keyboard Layout
 Alphanumeric Keys
 Modifier Keys
 Numeric Keypad
 Function Keys
 Cursor Movement Keys
 Special Purpose Keys
Standard Keyboard Layout
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’
3A-34
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
3A-35
The Mouse
 Optical mouse
 Light shown onto mouse pad
 Reflection determines speed and direction
 Requires little maintenance
3A-36
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
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The Mouse
 Benefits
 Pointer positioning is fast
 Menu interaction is easy
 Users can draw electronically
3A-38
Variants of the Mouse
 Trackballs
 Upside down mouse
 Hand rests on the ball
 User moves the ball
 Uses little desk space
3A-39
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
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Variants of the Mouse
 Track point
 Little joystick on the keyboard
 Move pointer by moving the joystick
3A-41
Ergonomics and Input Devices
 Ergonomics
 Study of human and tool interaction
 Concerned with physical interaction
 Attempts to improve safety and comfort
3A-42
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
3A-43
Carpal Tunnel Syndrome
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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
3A-45
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
3A-46
Chapter 2B
Inputting Data In Other Ways
Devices for the Hand
 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
3B-48
Devices for the hand
 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
3B-49
Devices for the hand
 Game Controllers
 Enhances gaming experience
 Provide custom input to the game
 Modern controllers offer feedback
 Joystick
 Game pad
3B-50
Optical Input Devices
 Allows the computer to see input
 Bar Code Readers
 Converts bar codes to numbers
 Computer find number in a database
 Works by reflecting light
 Amount of reflected light indicates number
3B-51
Optical Input Devices
 Image Scanners
 Converts printed media into electronic
 Reflects light off of the image
 Sensors read the intensity
 Filters determine color depths
3B-52
Optical input devices
 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
3B-53
Audiovisual Input Devices
 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
3B-54
Audiovisual Input Devices
 Musical Instrument Digital Interface
 MIDI
 Connects musical instruments to computer
 Digital recording or playback of music
 Musicians can produce professional results
3B-55
Audiovisual Input Devices
 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
3B-56
Audiovisual Input Devices
 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
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Chapter 3B
End of Chapter