1. Computer Software
Bayram Güzer

2. Software
Software is the planned, step-by-step set of instructions required to turn data into information that makes the computer useful.
Generally software can be categorized as
Application software
System software
Application software is used to solve a particular problem or perform a particular task
Examples;
Keeping track of store inventory
Designing a car engine
Draft the minutes of the meeting
Playing a game 2

3. Software
System software is the all programs related to coordinating computer operations
Examples;
Operating systems
Language translators
Convert program code to machine-readable form
Utility programs
Perform secondary tasks (everyday jobs) 3

4. Operating System
A set of programs that lies between application programs and the hardware
Manages computer’s resources (CPU, peripheral devices)
Establishes a user interface
Determines how user interacts with operating system
Provides and executes services for applications software 4

5. Kernel
The most important program in the operating system is the program that manages the operating system which is called as supervisor program or kernel.
It is loaded from hard drive into memory when computer is booted
Booting refers to starting the computer
Since it remains in memory permanently until power loss it is also referred to as resident.
It loads other operating system programs from disk storage as needed that is referred to as nonresident. 5 5

6. Operating Systems for Personal Computers
Platform is combination of computer hardware and operating system software
Wintel (Microsoft Windows running on an Intel-based PC) is most common
Common Operating Systems
Windows
MAC OS
Linux 6

7. MS-DOS Uses a command-line interface
Screen provides prompts for user
User types commands
Largely replaced by graphical user interfaces
Not user-friendly 7

8. Microsoft Windows Began as an operating environment for MS-DOS
Not a full-blown operating system; required MS-DOS
Uses a graphical user interface (GUI)
Users can use DOS commands and interface
Now a complete family of operating systems 8

9. Windows 3.1
Windows 3.1 is also known as the MS-DOS Operating Environment
A layer added “on top” of DOS
Separates operating system from user
Makes operating system easier to use
It is also called as a shell
A shell is a piece of software that provides an interface for users. Typically, the term refers to an operating system shell which provides access to the services of a kernel 9

10. Graphical User Interface (GUI)
Graphical user interface is the environment which users work with on-screen pictures called icons and menus rather than keyed-in commands.
User clicks an icon to perform tasks
There is a start Menu in lower left corner which launches programs
You can use menus to activate commands 10

11. Windows Features Long file names (up to 255 characters) Plug and Play
Makes installing hardware components easier
A user can install it simply by plugging it in and turning on the computer.
Object Linking and Embedding (OLE)
Allows user to embed or link one document to another
Embedding graphics into document and editing graphic within a document. 11

12. The Windows Family Windows 9x Corporate Market Windows XP
Windows Millennium Edition (ME)
Windows CE
Corporate Market
Windows NT
Windows 2000
Windows XP
Windows Vista
Windows 7 12 12

13. Windows 9x Serves home/consumer market
No longer a shell, but a self-contained operating system
Began with Windows 95
Next Generation:
Windows 98
Windows ME
Many improvements over Windows 3.1 13

14. Windows 98 Improvement
Internet/intranet browsing capabilities have been improved.
Support for state-of-the-art hardware, including DVD and multimedia are enriched.
Support for huge disk drives is provided.
Wizards: step-by-step software for installing, configuring, and using software easier. 14

15. Windows ME Enhancements
Multimedia support: Media Player, video editing
Enhanced reliability features
Home network support 15

16. Windows CE Scaled-back version of Windows 9x Used in Pocket PCs
Designed to work on machines with small screens and little storage
Used in Pocket PCs
Used in embedded systems
Computer devices integrated into other products; i.e., robots
CE.NET supports .NET platform 16

17. Corporate Market Windows NT Windows 2000
NT stands for “new technology”
Windows 2000 17

18. Windows NT Desktop looks and acts like Windows 98
Meant mostly for corporate, networked environments
Engineered for scalability (the ability to handle many users)
Stronger security features
It requires much more memory and hard disk space than Windows 98. 18

19. Windows 2000 The latest generation of Windows NT
Merges Windows NT 4.0’s stability with Windows 98’s setup and hardware awareness.
Dynamic layout features will detect what kind of screen you are on (handheld, TV, PC).
One computer “serves” many users
You identify yourself and the system knows your preferences
You get “your” desktop and files, regardless of which PC you use to log into the network 19

20. Windows XP
Brings consumer and corporate versions of Windows together into a single product
Has Home and Professional Editions
Enhancements 20

21. Windows XP Enhancements
Improved user interface
Much clearer and uncluttered desktop
More icons on redesigned Start Menu
Improved multimedia support
More personalization
Multiple user support
User can log off, leaving programs running, and allow another user to log on
Set up limited accounts for children to use; i.e., no inappropriate games or no Internet access
Internet support and protection 21

22. Windows Vista Windows Vista: Most recent version of Windows
Features the Aero visual interface
Transparency and animations
Live Thumbnails
The Vista Start menu is more modernized
Built-in security features
Improved networking and multimedia
Additional features
Sidebar, Instant Search, etc.
Hardware requirements for Vista have increased over earlier versions of Windows
Four editions (Home Basic, Home Premium, Business, and Ultimate) 22

23. Windows 7
Designed to fix the Vista debacle; sort of a streamlined Vista under the hood
Faster boot/shutdown times
Some “improvements” to the UI, handling media, Windows Explorer, IE8, wireless networking and setting up home networks 23

24. MAC OS Designed for the Macintosh computer
It is also known as the first commercially successful GUI
Has served as a model for Windows and other GUI products developed since Mac OS 24

25. UNIX Look for SCO Unixware/SCO Open Server for the latest version.
Developed in 1971 for use on the DEC minicomputer
Character-based system with command-line interface
Not tied to any family of processors
Runs on just about every type of system (PC, mainframe, workstation) from any manufacturer
Primary operating system in use on Internet servers
Handles many simultaneous users easily
Look for SCO Unixware/SCO Open Server for the latest version. 25

26. Linux Uses command-line interface Open-source concept
Many companies have created a GUI to work with Linux
Open-source concept
Source code is free
Users can download, change, and distribute the software
More stable than Windows
Applications relatively limited
Hardware compatibility is limited
It is mostly used by advanced users/IT professionals 26

27. Operating Systems for Networks
A networking operating system is an operating system that contains components and programs that allow a computer on a network to serve requests from other computer for data and provide access to other resources such as printer and file systems.
Some of the NOS functions are;
Handles network functions
Make resources appear as though they were running from client computers 27

28. Network Functions Common functions of the networks are listed below;
Sharing resources (hard disks and printers)
Providing data security
Troubleshooting the network
Administrative control of the network 28

29. Network Operating Systems
Windows NT Server
Windows 2000 Server
Windows .NET Server (Windows Server 2003)
Novell Netware
Novell Open Enterprise Server (OES)
OES-Linux
OES-Netware
Unix
SCO Unixware/SCO Open Server 29

30. Network Operating Systems
Unix-like
Minix
Solaris
Berkeley Software Distribution
Free BSD
Net BSD
Open BSD
Open Solaris
Linux 30

31. Network Operating Systems
Resource allocation is the process of assigning computer resources to certain programs and processes for their use
Main issues related to resource allocation
Sharing the Central Processing Unit
Sharing memory
Sharing storage resources
Sharing printing resources 31

32. Sharing the CPU There are three ways for sharing the cpu;
Multiprocessing
Multiprogramming
Time-Sharing 32

33. Multiprocessing
Multiprocessing is the use of a computer with multiple CPUs
Symmetric multiprocessing
treats all of the processing elements in the system identically
Asymmetric multiprocessing
system assigns certain tasks only to certain processors
Reserving only one CPU to responding all hardware interrupts 33

34. Multiprogramming Two or more programs executed concurrently
Programs take turns using the CPU
Event-driven
An interrupt suspends processing to allow another program to run
After the second program runs, the operating system returns the CPU to another program
Generally used for batch programs that do not require user input 34

35. Time-Sharing Programs take turns using the CPU Time-driven
Each user is given a slice of time (fraction of a second)
CPU works only on that user’s tasks during its time slice
Response time is the time between typed request and computer’s reply
Typically used in applications with many users 35

36. Sharing Memory Sharing memory is related to memory management
It divides memory into foreground and background sections
It also uses virtual storage which is also called as virtual memory 36

37. Memory Management Divides memory into separate partitions
Allocates memory to programs
Keeps programs separate from one another 37

38. Foreground and Background
Foreground is for programs with high priority that will receive more CPU time.
Background is for programs with lower priority that will receive less CPU time
Programs waiting to run are kept in queues based on their priority 38

39. Virtual Storage Programs currently executed are stored on disk
Portions of program brought into memory as needed
Minimizes the amount of memory needed
Can be implemented by paging
Divide memory into small, fixed-size pages
Page table keeps track of memory locations 39

40. Sharing Storage Resources
Keeps track of location of files
Responds to commands to manipulate files on the main computer.
Keeps track of input and output requests for files
Processes them in the order received 40

41. Sharing Printing Resources
Spooling is the process in a program which writes a line to a disk file rather than sending directly to a printer
When file is completed, it is placed in queue
File is printed when printer becomes available
Allows program to complete execution much more quickly
Writing to disk is much quicker than writing to printer 41

42. Utility Programs Perform secondary tasks Examples File manager
File compression
Others 42

43. File Manager Stores files in a hierarchical directory structure
Windows uses Windows Explorer 43

44. File Compression Reduces amount of space a file requires
Makes file take up less space on disk
Takes less time to transmit across communication lines 44

45. Other Utility Programs
Backup and Restore
Backup: make copies of disks and store in a safe place
Restore: restore files from backups
Disk defragmenter: reorganizes disk so all files are stored in contiguous locations
Device driver: handles commands for devices, such as printers and storage devices 45

46. Applications Software
Software used to solve a particular problem or perform a particular task 46

47. Acquiring Software: Traditional Ways
Custom software
Written by programmers hired by organization
Packaged (commercial) software
Purchased from a store, catalog, or Web site 47

48. Custom Software Specifically tailored to an organization’s needs
Organization hires computer programmers to design, write, test, and implement software
Can be extremely complex and take years to write 48

49. Packaged Software Sold in stores, catalogs, or Web sites
Sometimes downloaded from the Internet
Package contains one or more CDs or DVDs holding the software
Typically contains software documentation
Designed to be user-friendly 49

50. User-Friendly Software
Easy to use
Software should be sensitive for even a beginning user
Software can be used with minimum of training and documentation 50

51. Acquiring Software: New Ways
Open-Source software
Shareware
Freeware
Public Domain 51

52. Freeware Author provides it free for all to use Author keeps copyright
May place restrictions on its use
May not be altered or redistributed without permission 52

53. Public Domain Software that is not copyrighted
May be used and even altered without permission
Typically developed by universities and/or research institutions using government grants 53

54. Open-Source Software A variation of freeware
Source code made available
Source code: readable by humans
Other programmers can modify and redistribute the programs freely
Helps identify bugs and create improvements more easily 54

55. Shareware Copyrighted software, freely distributed for a trial period
If you like it, register it for a fee
Most authors add free documentation, enhancements, support, and updates to encourage people to register 55

56. Buying Commercial Software
4 ways for buying a commercial software;
Individual copies for each computer
Site license
Electronic software distribution
Application Service Provider 56

57. Site License
Software installed on some or all computers, depending on license terms
Customer keeps track of how many users
Number of users cannot exceed number of licenses
Customer copies and distributes software and manuals to users
Some organizations use network licenses
Software installed on server
License fee based on number of concurrent users 57

58. Electronic Software Distribution
Get software from the Internet
Typically freeware and shareware
Some commercial software
Typical scenario:
Download software for trial period
Software disables itself after trial period unless you register (pay) 58

59. Application Service Provider
Delivers applications to businesses via the Internet
ASP maintains software and data on its systems
Customers access applications as needed over the Internet
Alternative to creating and maintaining custom software or purchasing packaged software
“Rent” software, paying based on usage 59

60. Task-Oriented Software
Often called productivity software
Common categories
Word processing/Desktop publishing
Electronic spreadsheets
Database management
Graphics
Communications
Others 60

61. Working with Words Word Processing Desktop Publishing
Most widely used personal computer software
Create memos, reports, papers
Incorporate graphics into documents
Desktop Publishing
Used for high-level publishing needs
Newsletters
Brochures, promotional materials 61

62. Electronic Spreadsheets
Made up of rows and columns of numbers
Perform “what if” analysis
Change a cell and have spreadsheet recalculate
Present data graphically
Show expenses as a pie chart 62

63. Database Management
Handles the management of a collection of interrelated facts
Software can store, retrieve, update, and manipulate data
Can report data in many ways and print
Turn large amounts of data into information 63

64. Graphics Graphics software creates graphs and charts from numeric data
Spot trends and compare data more easily
Visual evidence more compelling
Included in spreadsheet programs
Presentation graphics creates “slide show” presentations
Combine high-quality graphics, audio, and video 64

65. Communications
The ability to hook the computer up to phone line or cable and communicate with another computer
Typically connected over the Internet
Needs a browser to access other locations on the Internet 65

66. Other Task Software Personal Information Managers Office Suite
Keep track of activities
Typically include appointment calendar, address book, and task manager
Office Suite
A group of basic applications that work together
Easy to share data among applications
Similar look and feel among applications
Integrated application
A “stripped down” version of the office suite 66

67. Business Software Vertical Market software Software for Workgroups
Small Business software 67

68. Vertical Market Software
Written for a particular type of business
Written by companies who have a comprehensive knowledge of that industry
Allows business to easily maintain information on the business, customers, vendors
Encompasses all of the business’s activities 68

69. Groupware Lets a group of people share or track information together
Also called collaborative software
Often combines electronic mail, networking, scheduling, and database technology
Data stored in one central location
Often used by organizations with remote employees 69

70. Software for a Small Business
Small Office/Home Office (SOHO)
Moderately priced software to perform functions aimed at small business
Examples:
Accounting software
Writing and advertising
Customer service
Keeping contacts
Making sales pitches 70

71. Ethics and Application Software
Piracy: the acquisition and use of illegal copies of software
Counterfeiting: copying large numbers of CD-ROMs or DVD-ROMs and packaging them to look like the real thing
Unauthorized copying of software is stealing 71

72. Software Piracy Examples of piracy
Copying software from a lab or from a friend
Buying 2 or 3 copies of software and distributing it to dozens or hundreds of employees
Buying 1 copy of software and installing it on several computers at home 72

73. Computers and People
Most organizations have some sort of information technology department
Made up of people who are responsible for the organization’s computer resources
Maintain data and provide services to end users 73

74. Computer People Data entry operators prepare data for processing
Computer operators monitor systems, keep peripherals running, and make backups
Librarians catalog processed disks and tapes
Programmers design, write, test, implement, and maintain computer programs 74

75. Computer People Systems analysts plan and design entire systems
Must have knowledge in programming, as well as knowledge of the business
Network managers implement and maintain organization’s network(s)
Chief Information Officer (CIO) makes key technology decisions
A key member of the organization’s strategic decision-making team 75

76. References
Capron, H. L. (2000). Computers Tools for an Information Age.(6th ed.). New Jersey, USA: Prentice Hall.
Shell. (2009). Retrieved 30 December 2009 from Shell_(computing)
Network Operating Systems. (2009). Retrieved 30 December 2009 from Network_operating_system
roundtables/presentations/SIRT_Roundtable-New%20OSes_USB_drives-Sept09.ppt 76