1. Software Basics: The Ghost in the Machine
Chapter 4
Software Basics:
The Ghost in the Machine
 2002 Prentice Hall

2. Topics Processing with Programs Software Applications: Tools for Users
System Software: The Hardware-Software Connection
The User Interface: The Human-Machine Connection
Tomorrow’s User Interfaces
 2002 Prentice Hall

3. Processing with Programs
Software programs are:
Stored in memory
Instructions that tell the computer what to do
Designed to solve problems
Leonardo da Vinci called music ”the shaping of the invisible,“ and his phrase is even more apt as a description of software.
—Alan Kay, developer of the concept of the personal computer
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4. Food for Thought Suzanne’s French Toast Fantastique:
Combine 2 slightly beaten eggs with 1 tsp vanilla extract, ½ tsp cinnamon, 1 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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5. A Fast, Stupid Machine Computers:
Perform arithmetic and comparisons capabilities
Follow precise instructions to perform an operation
Execute instructions quickly and accurately
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6. A Fast, Stupid Machine Programmers begin with an algorithm
An algorithm 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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7. The Language of Computers
Machine Language numeric codes to represent data
High-level language fall between machine language and natural human language
Compliers translates high-level language into
Natural Languages include the languages spoken by humans
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8. Software Applications: Tools for Users
Software applications include:
Consumer Applications
Integrated Software
Vertical-market
Custom Software
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9. 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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10. 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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11. 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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12. 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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13. Disclaimers
Software manufacturers limit their liability for software problems by selling software “as is”
Given the difficulty of this task, most programs work amazingly well—but not perfectly
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14. Licensing Licensing agreements limit your right to:
Make copies of software disks
install software on hard drives
transfer information to other users
Commercial software is copyrighted so it can’t be legally duplicated for distribution to others.
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15. Distribution
Software is distributed through direct sales forces to corporations and other institutions.
Software is sold to consumers through:
retail stores
mail-order catalogs
Web sites.
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16. Integrated Applications and Suites: Software Bundles
Multipurpose software includes most of these modules:
Word processing
Database
Spreadsheet
Graphics
Telecommunications
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17. 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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18. Vertical-Market and Custom Software
Job-specific software:
Medical billings
Library cataloging
Restaurant management
Single-client software needs
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19. System Software: The Hardware-Software Connection
System software is a class of software that includes:
The operating system
Utility programs
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20. 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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21. Utility Programs
Upgrades allow you to pay a fee to get the latest software version
repairing damaged files
copying files from one storage device to another
translating files so different software can read them
guarding against viruses
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22. 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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23. 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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24. 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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25. 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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26. 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, the Macintosh™ computer was designed with this interface in mind
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27. Graphical User Interfaces: Windows
Windows 95 and 98 are similar in many ways to the Mac OS
Several versions of Windows exist for business and home users
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28. Why WIMP Won Windows, Icons, Menus, and Pointing devices
They’re intuitive
They’re consistent
They’re forgiving
They’re protective
They’re flexible
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29. 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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30. 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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31. Hardware & Software Platforms
Windows XP
Windows ME
Windows 2000
Windows CE
Palm OS
IBM’s OS/2
Mac OS/9
Mac OS/X
Linux & UNIX
BeOS
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32. Tomorrow’s User Interfaces
Future interfaces will probably:
Make individual applications obsolete
Include more network applications
Support natural language interfaces such talking to the machine
Include artificial intelligence and agents
Be based on virtual reality
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33. Rules of Thumb Consumer Concepts
Before you buy:
Determine what you can afford
Allow for “extras”
Join a user group or talk with other computer and software owners
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34. Rules of Thumb: Consumer Concepts
Consider:
If the processor can handle your demands
If you will be able to upgrade
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
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35. 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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