2. The Computer Defined
• Electronic device
• Converts data into information
• Modern computers are digital
– Two digits combine to make data
• Older computers were analog
– A range of values made data
4. Computers for Individual Use
• Desktop computers
– The most common type of computer
– Sits on the desk or floor
– Performs a variety of tasks
• Workstations
– Specialized computers
– Optimized for science or graphics
– More powerful than a desktop
5. Computers for Individual Use
• Notebook computers
– Small portable computers
– Weighs between 3 and 8 pounds
– About 8 ½ by 11 inches
– Typically as powerful as a desktop
– Can include a docking station
6. Computers for Individual Use
• Tablet computers
– Newest development
in portable computers
– Input is through
a pen
– Run specialized
versions of office
products
7. • Handheld computers
– Very small computers
– Personal Digital Assistants (PDA)
– Note taking or contact management
– Data can synchronize with a desktop
• Smart phones
– Hybrid of cell phone and PDA
– Web surfing, e-mail access
Computers for Individual Use
8. Computers for Organizations
• Network servers
– Centralized computer
– All other computers connect
– Provides access to network resources
– Multiple servers are called server farms
– Often simply a powerful desktop
9. Computers for Organizations
• Mainframes
– Used in large
organizations
– Handle thousands
of users
– Users access
through a terminal
10. Computers for Organizations
• Minicomputers
– Called midrange computers
– Power between mainframe and desktop
– Handle hundreds of users
– Used in smaller organizations
– Users access through a terminal
11. Computers for Organizations
• Supercomputers
– The most powerful
computers made
– Handle large and
complex calculations
– Process trillions
of operations
per second
– Found in research
organizations
12. Computers In Society
• More impact than any other invention
– Changed work and leisure activities
– Used by all demographic groups
• Computers are important because:
– Provide information to users
– Information is critical to our society
– Managing information is difficult
13. Computers In Society
• Computers at home
– Many homes have multiple computers
– Most American homes have Internet access
– Computers are used for
• Business
• Entertainment
• Communication
• Education
14. Computers In Society
• Computers in education
– Computer literacy required at all levels
• Computers in small business
– Makes businesses more profitable
– Allows owners to manage
• Computers in industry
– Computers are used to design products
– Assembly lines are automated
15. Computers In Society
• Computers in government
– Necessary to track data for population
• Police officers
• Tax calculation and collection
– Governments were the first computer users
16. Computers In Society
• Computers in health care
– Revolutionized health care
– New treatments possible
– Scheduling of patients has improved
– Delivery of medicine is safer
17. Parts of the Computer System
• Computer systems have four parts
– Hardware
– Software
– Data
– User
18. Parts of the Computer System
• Hardware
– Mechanical devices in the computer
– Anything that can be touched
• Software
– Tell the computer what to do
– Also called a program
– Thousands of programs exist
19. Parts of the Computer System
• Data
– Pieces of information
– Computer organize and present data
• Users
– People operating the computer
– Most important part
– Tell the computer what to do
23. Major Computer Hardware Components
• Processing devices (CPU)
– Brains of the computer
– Carries out instructions from the program
– Manipulate the data
– Most computers have several processors
– Central Processing Unit (CPU)
– Secondary processors
– Processors made of silicon and copper
24. Essential Computer Hardware
• Memory devices – Main Memory
– Stores data or programs
– Random Access Memory (RAM)
• Volatile
• Stores current data and programs
• More RAM results in a faster system
– Read Only Memory (ROM)
• Permanent storage of programs
• Holds the computer boot directions
25. 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
26. Essential Computer Hardware
• Secondary 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
27. Software Runs the Machine
• Tells the computer what to do
• Reason people purchase computers
• Two types
– System software
– Application software
28. Software Runs the Machine
• System software
– Most important software
– Operating system
• Windows XP, Windows 10, MacOS, Linux
– Network operating system (OS)
• Windows Server
– Utility
• Symantec AntiVirus
29. Software Runs the Machine
• Application software
– Accomplishes a specific task
– Most common type of software
• MS Word
– Covers most common uses of computers
30. Computer Data
• Fact with no meaning on its own
• Stored using the binary number system
• Data can be organized into files
31. Computer Users
• Role depends on ability
– Setup the system
– Install software
– Mange files
– Maintain the system
• “Userless” computers
– Run with no user input
– Automated systems
33. How Computers Represent Data
• Number systems
– A manner of counting
– Several different number systems exist
• Decimal number system
– Used by humans to count
– Contains ten distinct digits
– Digits combine to make larger numbers
34. How Computers Represent Data
• Binary number system
– Used by computers to count
– Two distinct digits, 0 and 1
– 0 and 1 combine to make numbers
35. How Computers Represent Data
• Bits and bytes
– Binary numbers are made of bits
– Bit represents a switch
– A byte is 8 bits
– Byte represents one character
36. How Computers Represent Data
• Text codes
– Converts letters into binary
– Standard codes necessary for data transfer
– ASCII
• American English symbols
– Extended ASCII
• Graphics and other symbols
– Unicode
• All languages on the planet
37. How Computers Process Data
• The CPU
– Central Processing Unit
– Brain of the computer
– Control unit
• Controls resources in computer
• Instruction set
– Arithmetic logic unit
• Simple math operations
• Registers
38. How Computers Process Data
• Machine cycles
– Steps by CPU to process data
– Instruction cycle
• CPU gets the instruction
– Execution cycle
• CPU performs the instruction
– Billions of cycles per second
– Pipelining processes more data
– Multitasking allows multiple instructions
39. How Computers Process Data
• Memory
– Stores open programs and data
– Small chips on the motherboard
– More memory makes a computer faster
40. How Computers Process Data
• Nonvolatile memory
– Holds data when power is off
– Read Only Memory (ROM)
– Basic Input/Output System (BIOS)
– Power On Self Test (POST)
41. How Computers Process Data
• Flash memory
– Data is stored using physical switches
– Special form of nonvolatile memory
– Camera cards, USB key chains
42. How Computers Process Data
• Volatile memory
– Requires power to hold data
– Random Access Memory (RAM)
– Data in RAM has an address
– CPU reads data using the address
– CPU can read any address
44. Functions of Operating Systems
• Provide a user interface
• Run programs
• Manage hardware devices
• Organized file storage
45. Types of Operating Systems
• Real-time operating system
– Very fast small OS
– Built into a device
– Respond quickly to user input
– MP3 players, Medical devices
46. Types of Operating Systems
• Single user/Single tasking OS
– One user works on the system
– Performs one task at a time
– MS-DOS and Palm OS
– Take up little space on disk
– Run on inexpensive computers
47. Types of Operating Systems
• Single user/Multitasking OS
– User performs many tasks at once
– Most common form of OS
– Windows 10 and MacOS
– Require expensive computers
– Tend to be complex
48. Types of Operating Systems
• Multi-user/Multitasking OS
– Many users connect to one computer
– Each user has a unique session
– UNIX, Linux, and VMS
– Maintenance can be easy
– Requires a powerful computer
50. Providing a User Interface
• User interface
– How a user interacts with a computer
– Require different skill sets
51. Providing a User Interface
• Graphical user interface (GUI)
– Most common interface
• Windows, MacOS , Gnome, KDE
– Uses a mouse to control objects
– Uses a desktop metaphor
– Shortcuts open programs or documents
– Open documents have additional objects
– Task switching
– Dialog boxes allow directed input
52. Providing a User Interface
• Command-line interfaces
– Older interface
• DOS, Linux, UNIX
– User types commands at a prompt
– User must remember all commands
– Included in all GUIs
54. Running Programs
• Many different applications supported
• System call
– Provides consistent access to OS features
• Share information between programs
– Copy and paste
– Object Linking and Embedding
55. Managing Hardware
• Programs need to access hardware
• Interrupts
– CPU is stopped
– Hardware device is accessed
• Device drivers control the hardware
56. Organizing Files and Folders
• Organized storage
• Long file names
• Folders can be created and nested
• All storage devices work consistently
57. Enhancing an OS
• Utilities
– Provide services not included with OS
– Goes beyond the four functions
– Firewall, anti-virus and compression
– Prices vary
58. Enhancing an OS
• Backup software
– Archives files onto removable media
– Ensures data integrity
– Most OS include a backup package
– Many third-party packages exist
59. Enhancing an OS
• Anti-virus software
– Crucial utility
– Finds, blocks, and removes viruses
– Must be updated regularly
– McAfee and Norton Anti-Virus
60. Enhancing an OS
• Firewall
– Crucial utility
– Protects your computer from intruders
– Makes computer invisible to hackers
– Zone Labs is a home firewall
– Cisco sells hardware firewalls
61. Enhancing an OS
• Intrusion detection
– Often part of a firewall package
– Announces attempts to breach security
– Snort is a Linux-based package
63. Acquiring Software
• Commercial software
– Software that must be purchased
– Stand-alone products
• Solve one type of problem
– Software suites
• Integrated tools that work together
• Solve many problems
– Shareware
• Try before you buy
• May deactivate if not purchased
64. Acquiring Software
• Freeware
– No obligation to purchase
• Donations often accepted
– Software may be distributed freely
– Public domain software
65. Acquiring Software
• Open source
– Programs distributed with source code
– Allows users to modify the software
– Modifications and comments are welcome
– Linux and OpenOffice
66. Word Processing Programs
• Creates text documents
• Graphics and other objects are
supported
• Professional quality can be achieved
• Simple web pages may be created
67. Word Processing Programs
• Formatting text
– Controls the document’s appearance
– Character formatting tools
• Fonts
• Type style
– Paragraph formatting tools
• Line spacing
• Tabs
– Document formatting tools
• Margins
• Headers
68. Spreadsheet Programs
• Calculates numbers and finances
• Data viewable in many ways
– Tables
– Graphs
• Complex calculations can be automated
69. Spreadsheet Programs
• Interface
– Rows, columns and cells
• Cell holds data or formulas
– Formula bar
– Labels describe cell contents
– Values
– Dates
– Formulas
70. Presentation Programs
• Creates slides or transparencies
• Complete set is a presentation
• Enhances a speech or lecture
• Color and animation enhance the slides
72. Presentation Programs
• Creating a presentation
– Templates can simplify the process
– Build the slides
• Pick a layout
• Enter the desired text
• Apply special formatting
– Continue adding slides in order
– Apply slide transitions if desired
73. Presentation Programs
• Presenting slide shows
– Use to enhance a speech
– Mouse click advances to next slide
– Physical transparencies on an overhead
– Computer screen delivery
– Large monitor delivery
– Data projector
75. 13B-75
Programming Languages
• Used to generate source code
• Avoids using machine code
• Have strict rules of syntax
– Symbols and punctuation have meaning
– Spelling must be exact
• Code is converted into machine
language
77. 13B-77
Language Categories
• Second generation languages
– Assembly languages
– Statements that represent machine code
– Code converted by an assembler
– Still used to optimize video games
78. 13B-78
Language Categories
• Third generation languages (3GL)
– First higher level language
– Supports structured and OOP
• Code is reusable
• Code is portable
– Typically written in an IDE
– C/C++ creates games and applications
– Java creates web applets
– ActiveX creates Web and Windows applets
79. 13B-79
WWW Development Languages
• Extensible Markup Language (XML)
– Stores data in a readable format
– Looks like HTML
– Allows developers to create tags
– Depends on HTML for formatting
80. 13B-80
WWW Development Languages
• Extensible HTML Mobile Profile
– XHTML MP
– Initially Wireless Markup Language (WML)
– Creates pages viewable on a handheld
82. 13B-82
Systems Development Life Cycle
• Phase 1: Needs Analysis
– Users identify a need
– Need is clearly defined using tools
83. 13B-83
Systems Development Life Cycle
• Phase 2: Systems design
– Solution to the need is defined
– Many tools are used
– Prototypes of the solution are built
84. 13B-84
Systems Development Life Cycle
• Phase 3: Development
– Solution to the problem is built
– Programmers write the solution
– Technical writers document the process
– Solution is continually tested
85. 13B-85
Systems Development Life Cycle
• Phase 4: Implementation
– The solution is installed
– Users are converted to the new system
– Trainers are important in this phase
86. 13B-86
Systems Development Life Cycle
• Phase 5: Maintenance
– IT professionals monitor the product
– Bugs are found and fixed
– New features are added
