Software Basics

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Software Basics
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• The Ghost in the Machine

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Chapter Outline
All experience shows technological changes
profoundly transform political and social
relationships. John von Neumann

• Processing with Programs
• Software Applications Tools for Users
• System Software The Hardware-Software Connection
• The User Interface The Human-Machine Connection
• Tomorrows User Interfaces

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Processing with Programs

• Software programs are

• stored in memory
• a set of instructions that tell a computer what
  to do
• designed to solve problems

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Food for Thought
Suzannes French Toast Fantastique

• Combine 2 slightly beaten eggs with 1 tsp vanilla
  extract, ½ tsp cinnamon, ? cup milk
• Dip 6 slices of bread in mixture
• Fry in small amount of butter until golden brown
• Serve bread with maple syrup, sugar, or tart jelly

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A Fast, Stupid Machine

• Computers
• Have limited capabilities
• Can only do basic mathematics and logical
  comparisons
• Must be instructed with programs what to do

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The Language of Computers

• Programmers begin with an algorithm, which is
• A set of step-by-step instructions (written in a
  natural language, e.g., English)
• Algorithms are ambiguous, error-prone
  generalities
• Algorithms are translated into the vocabulary of
  a programming language

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Programming Languages
Bridge the gap
Human language
Numeric code

• COBOL, BASIC, and C

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Software ApplicationsTools for Users

• Software applications include

• Consumer software
• Integrated software
• Vertical-market and custom software

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Consumer Applications

• Consumer software differs from other types (music
  CDs, videos, etc.) based on
• Documentation
• Upgrade options
• Compatibility
• Warranty
• Extent of ownership/license

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Documentation

• Documentation includes
• Printed tutorial and reference manuals that
  explain how to use the software
• On-line manuals and help screens which offer
  immediate help to the user

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Upgrades

• Upgrades allow you to pay a fee to get the latest
  software version

• Newer releases often have additional features and
  fewer bugs

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Compatibility

• Compatibility allows software to function
  properly with the hardware, operating system, and
  peripherals

• Programs written for one type of computer system
  may not work on another

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Warranty
Buyer Beware!

• Software manufacturers limit their liability for
  software problems byselling their software as
  is
• Error-free software does not exist

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Ownership/Licensing

• Three categories
• Purchased software grants you a license to use
  the software as the software company tells you
• Shareware software is free for the trying, but a
  nominal fee is to be paid to the programmer if
  you continue to use it
• Public domain software is legally free and cannot
  be owned or licensed

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Integrated Applications and Suites Software
Bundles

• Multipurpose software includes most of these
  modules
• Word processing
• Database
• Spreadsheet
• Graphics
• Telecommunications

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Integrated Software Advantages

• Costs less than buying the applications
  individually
• Data is easily transferred between modules
• Commands used in each module are usually the same
• Usually there is a seamless integration of the
  modules

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Vertical-Market andCustom Software

• Job-specific software
• Medical billings
• Library cataloging

• Restaurant management
• Single-client software needs

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What the Operating System Does

• The operating system controls
• Communication with peripherals
• Coordination of concurrent processing
• Memory management
• Monitoring of resources and security
• Management of programs and data
• Coordinating network communications

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Utility Programs
Utility software controls tasks such as

• repairing damaged files
• making it easy for users to copy files from one
  storage device to another
• translating files so differentsoftware can read
  them
• guarding against viruses

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Where the Operating System Lives

• Some computers store their operating system in
  ROM

• Others include only part of it in ROM
• The remaining system is loaded into memory
  (booting)
• Most of the time it works behind the scenes

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The User Interface The Human-Machine Connection

• The user interface is what the user sees on the
  screen

• Two major user interface types
• Character-based interface
• Graphical user interface (GUI)

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A Character-Based Interface MS-DOS

• This is a disk operating system in which the user
  interacts using characters
• letters
• numbers
• symbols

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A Character-Based User Interface MS-DOS

• MS-DOS is the most widely used general-purpose
  operating system
• Features include
• Command-line interface (commands are typed)
• Menu-driven interface (commands are chosen from
  on-screen lists)

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Graphical User Interfaces Macintosh

• This is a disk operating system in which the user
  interacts with the computer by using a pointing
  device (e.g. a mouse)
• As early as 1984, theMacintosh computerwas
  designed with thisinterface in mind

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Graphical User Interfaces Windows

• Windows 95and 98 are similar in many ways to
  the Mac OS
• Several versions of Windows exist for business
  and home users

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Why WIMP Won

• Windows, Icons, Menus, and Pointing devices

• Theyre intuitive
• Theyre consistent
• Theyre forgiving
• Theyre protective
• Theyre flexible

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Multiple User Operating Systems UNIX and Linux

• UNIX was developed at Bell Labs before personal
  computers were available
• Linux was created by Linus Torvalds and continues
  to be a work-in-progress
• Linux is free for anyone to use or improve

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Multiple User Operating Systems UNIX and Linux

• UNIX remains a dominant Internet operating
  system for Internet servers.

• These systems allow a timesharing computer to
  communicate with several other computers or
  terminals at once.

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Hardware Software Platforms

• Windows 9x(ME)
• Windows 2000
• Windows CE
• Palm OS

• IBMs OS/2
• Mac OS/9
• Mac OS/X
• UNIX Linux
• BeOS

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Rules of ThumbConsumer Concepts
Before you buy

• Determine what you can afford

• Allow for extras

• Join a user group ortalk with other computerand
  software owners

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Rules of Thumb Consumer Concepts
Consider

• What kind of tasks you will be doing
• If your computer can be customized to fit your
  needs (such as video editing)
• How much computer power you need

• If the processor canhandle your demands
• If you will be able to upgrade

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Rules of Thumb Consumer Concepts
Consider

• If you need a high-speed modem or network
  connection
• Whether portability or permanent connection of
  peripherals is important
• Which kind of user interface will help you do
  your work easier

• If you should have the same machine as those you
  work with
• If you are buying from a reputable company
• What kind of support is available

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Tomorrows User Interfaces
Future interfaces will probably

• Make individual applications obsolete
• Support natural languages(talk to the machine
  and it talks back)
• Include artificial intelligenceand agents that
  fit our needs
• Be based on virtual reality(data in
  three-dimensional physical space)

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