1. Software Basics The Ghost in the Machine 4

2.  2001 Prentice Hall4.2 Chapter Outline 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 “All experience shows technological changes profoundly transform political and social relationships.” John von Neumann

3.  2001 Prentice Hall4.3 Processing with Programs Software programs are: –stored in memory –a set of instructions that tell a computer what to do –designed to solve problems

4.  2001 Prentice Hall4.4 Food for Thought 1.Combine 2 slightly beaten eggs with 1 tsp vanilla extract, ½ tsp cinnamon,  cup milk 2.Dip 6 slices of bread in mixture 3.Fry in small amount of butter until golden brown 4.Serve bread with maple syrup, sugar, or tart jelly Suzanne’s French Toast Fantastique:

5.  2001 Prentice Hall4.5 A Fast, Stupid Machine Computers: –Have limited capabilities –Can only do basic mathematics and logical comparisons –Must be instructed with programs what to do

6.  2001 Prentice Hall4.6 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

7.  2001 Prentice Hall4.7 Programming Languages Bridge the gap Human language Numeric code COBOL, BASIC, and C++

8.  2001 Prentice Hall4.8 Software Applications: Tools for Users Software applications include: –Consumer software –Integrated software –Vertical-market and custom software

9.  2001 Prentice Hall4.9 Consumer Applications Consumer software differs from other types (music CDs, videos, etc.) based on: –Documentation –Upgrade options –Compatibility –Warranty –Extent of ownership/license

10.  2001 Prentice Hall4.10 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

11.  2001 Prentice Hall4.11 Upgrades Newer releases often have additional features and fewer bugs Upgrades allow you to pay a fee to get the latest software version

12.  2001 Prentice Hall4.12 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

13.  2001 Prentice Hall4.13 Warranty Software manufacturers limit their liability for software problems by selling their software “as is” Error-free software does not exist Buyer Beware!

14.  2001 Prentice Hall4.14 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

15.  2001 Prentice Hall4.15 Integrated Applications and Suites: Software Bundles Multipurpose software includes most of these modules: –Word processing –Database –Spreadsheet –Graphics –Telecommunications

16.  2001 Prentice Hall4.16 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

17.  2001 Prentice Hall4.17 Vertical-Market and Custom Software Job-specific software: - Medical billings - Library cataloging - Restaurant management - Single-client software needs

18.  2001 Prentice Hall4.18 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

19.  2001 Prentice Hall4.19 Utility Programs –repairing damaged files –making it easy for users to copy files from one storage device to another –translating files so different software can read them –guarding against viruses Utility software controls tasks such as:

20.  2001 Prentice Hall4.20 Where the Operating System Lives 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 Some computers store their operating system in ROM

21.  2001 Prentice Hall4.21 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)

22.  2001 Prentice Hall4.22 A Character-Based Interface: MS-DOS This is a disk operating system in which the user interacts using characters –letters –numbers –symbols

23.  2001 Prentice Hall4.23 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)

24.  2001 Prentice Hall4.24 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

25.  2001 Prentice Hall4.25 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

26.  2001 Prentice Hall4.26 Why WIMP Won Windows, Icons, Menus, and Pointing devices They’re intuitive They’re consistent They’re forgiving They’re protective They’re flexible

27.  2001 Prentice Hall4.27 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

28.  2001 Prentice Hall4.28 UNIX remains a dominant Internet operating system for Internet servers. Multiple User Operating Systems: UNIX and Linux These systems allow a timesharing computer to communicate with several other computers or terminals at once.

29.  2001 Prentice Hall4.29 Hardware & Software Platforms Windows 9x(ME) Windows 2000 Windows CE Palm OS IBM’s OS/2 Mac OS/9 Mac OS/X UNIX & Linux BeOS

30.  2001 Prentice Hall4.30 Rules of Thumb Consumer Concepts Before you buy: –Join a user group or talk with other computer and software owners –Allow for “extras” –Determine what you can afford

31.  2001 Prentice Hall4.31 Rules of Thumb: Consumer Concepts 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 Consider: If the processor can handle your demands If you will be able to upgrade

32.  2001 Prentice Hall4.32 Rules of Thumb: Consumer Concepts 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 Consider: 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

33.  2001 Prentice Hall4.33 Tomorrow’s User Interfaces –Make individual applications obsolete –Support natural languages (talk to the machine and it talks back) –Include artificial intelligence and agents that fit our needs –Be based on virtual reality (data in three-dimensional physical space) Future interfaces will probably: