2. COMPUTER SOFTWARE EDIT Module 1: Introduction to Information Technology

3. Think of a computer as a robot. What do you want it to do?

4. We Want a Computer To: 1. Read input data from source documents or secondary storage. 2. Process the data. 3. Display the results. 4. Print the results. 5. Store the results. 6. Transmit the results. 7. Protect itself and the data. 8. Keep track of things that it is doing to restart. 9. Count things to reflect performance. 10. Do multiple things at the same time.

5. For the computer to be able to perform all these requires the user to instruct the computer software to control the machine

6. Why is this topic important Hardware is the engine and software is the gas that makes it run. To understand software concepts is to understand how real work gets done on computer-based systems within a business. To understand software is to appreciate the specific details that must be addressed for a new computer-based application to be implemented.

7. Important Topics Major categories of software. The importance of operating systems and related systems software. The increasing importance of application packages. Challenges to implement application packages. The evolution of programming languages and the reason for so many languages.

8. Computer Software The detailed instructions that control the operation of a computer system. Provide tools to people. Intermediary between people and data. Manage the computer resources. Selecting appropriate software for an enterprise is a key management decision.

9. Overview of Computer Software General- Purpose Programs General- Purpose Programs Application- Specific Programs Application- Specific Programs System Management Programs System Management Programs System Development Programs System Development Programs Application Software Application Software Computer Software Computer Software System Software System Software

10. Trends in Computer Software First Generation First Generation Second Generation Second Generation Third Generation Third Generation Fourth Generation Fourth Generation Fifth Generation Fifth Generation User-Written Programs Machine Languages Packaged Programs Symbolic Languages Operating Systems High-Level Languages DBMS Fourth- Generation Languages Microcomputer Packages Natural & Object-Oriented Languages Multipurpose Graphic- Interface Network-enabled Expert-Assisted Packages Trend: Toward Easy-to-Use Multipurpose Network-Enabled Application Packages for Productivity and Collaboration Trend: Toward Visual or Conversational Programming Languages and Tools

11. Application Software: End User Applications 1) General Purpose Application Programs Software Suites – Microsoft Office Software Suites – Microsoft Office –Word Processing - Word / Works / Claris –Spreadsheet – Excel / FoxPro / Lotus –Database Managers - Access / Dbase/Sybase Web Browsers – Internet Explorer / Netscape Web Browsers – Internet Explorer / Netscape Electronic Mail – MS Outlook / Express / Eudora Electronic Mail – MS Outlook / Express / Eudora Presentation Graphics – Power Point / Flash Presentation Graphics – Power Point / Flash

12. Application Software: End User Applications 2) Application-Specific Programs Application Software Packages support managerial and operational uses: Application Software Packages support managerial and operational uses: –Accounting –Transaction Processing –Customer Relationship Management –Electronic Commerce

13. System Software: Computer System Management 1) System Management Programs Operating System -Resource Management -File Management -Task Management Network Management Programs Database Management Systems System Utilities

14. System Software: Computer System Management 2) System Development Programs Programming Language - BASIC / C++ / COBOL / JAVA/TURBO-PASCAL Programming Translators -Assemblers – translates assembler language -Compilers – translates high level language [ translate the program (source code) into machine code (object code), then execute the object code.]

15. Programming Languages Machine Languages Use binary coded instructions 1001 1100 1101 High Level Languages Use brief statements Compute X = Y + Z Markup Languages Use embedded control codes Assembler Languages Use symbolic coded instructions LOD Y ADD Z Fourth Generation Languages Use natural statements Object-Oriented Languages Define objects that contain data and actions Document.write (“Hi There”) First heading <!ELEMENT Product (#Item | manuf)> SUM THE FOLLOWING NUMBERS

16. In short: Software Software –Application vs. System Application Software Application Software –General purpose applications for end users System Software System Software –Manage hardware, software, network, data resources Operating Systems –Five basic functions: »User interface »Resource Management »File Management »Task Management »Utilities for support services Programming Languages –Five major levels: »Machine language »Assembler language »High-level language »Fourth-Generation »Object-Oriented

17. Systems Software Definition: Definition: –All programs related to coordinating computer operations Components Components –Operating System –Utility programs –Program language translators

18. Operating System Hidden Software Definition – provides access to all resources Definition – provides access to all resources Kernel Kernel –Manages the operating system –Memory resident –Loads set of programs that lies between applications software and the hardware –Fundamental software that controls non-resident portions of the OS as needed Booting – Loads the kernel into memory Booting – Loads the kernel into memory

19. Operating System A software program that acts as an intermediary between a user of a computer and the computer hardware. Exist because it is a reasonable way to solve the problem of creating a usable computer by better managing the computer resources. The basis for standardization of application software. (the platform)

20. Functions of an Operating System Resource Management Resource Management Task Management Task Management User Interface User Interface File (Data) Management File (Data) Management Utilities and Other Functions Utilities and Other Functions Use of hardware resources Managing the accomplishment of tasks Managing Data and Program Files Sort, Merge, Performance, etc.

21. Functions of OS Manage the computer’s resources Manage the computer’s resources –CPU –Memory –Disk drives –Printers Establish a user interface Establish a user interface Execute and provide services for applications software Execute and provide services for applications software Carries out all input and output operation Carries out all input and output operation

22. Multiprogramming - executing two or more programs concurrently using the same computer. Multiprocessing - executing two or more instructions simultaneously in a single computer by using multiple central processing units. Graphical User Interface (GUI) - part of the operating system that uses graphic icons to issue commands and make selections. Operating System Functions

23. User Interface Facilitates communication between the user and the operating system Facilitates communication between the user and the operating system Two forms Two forms –Command line »Text-based »Key commands »Examples: MS-DOS, Unix –Graphical user interface (GUI) »Visual images »Menus »Examples: Windows, Mac OS, Linux

24. UNIX Linux OS/2 Mac OS IBM MVS, VM DOS Windows.X Windows NT Popular Operating Systems

25. OS is Hidden User interested in application software to make the PC useful User interested in application software to make the PC useful Application software is platform specific Application software is platform specific User must be aware of the type of OS User must be aware of the type of OS User should be aware of the functions of OS User should be aware of the functions of OS

26. What is the platform of your system? A common question posed to a system vendor, manufacturer or even the organization utilizing the system…..

27. Platform Definition: Definition: Computer hardware and operating system software that dictate what other software can run E.g. Wintel E.g. Wintel Intel-based PC running on Microsoft Windows Microsoft Windows

28. Types of OS Command line Single user PC Network Operating System (NOS)

29. Command-line: MS-DOS Command-line interface Command-line interface Prompt – system is waiting for you to do something Prompt – system is waiting for you to do something Key a command Key a command Not user-friendly Not user-friendly

30. Single-user PC: Microsoft Windows Graphical user interface Graphical user interface Eases access to the OS Eases access to the OS Most new computers come with Windows already installed Most new computers come with Windows already installed

31. Network Operating System NOS Designed to permit computers on a network to share resources Designed to permit computers on a network to share resources Examples Examples –Windows 2000 Server –Novell Net Ware Provides Provides –Data security –Troubleshooting –Administrative control

32. NOS Functions Split between client and server computers Split between client and server computers Server Server –File management Client Client –Requests to the server –Messaging –Has own local OS Makes the resources appear as if they are local to the client’s computer Makes the resources appear as if they are local to the client’s computer

33. Early Days of Windows OS Operating environment for MS-DOS Shell – layer added between users and DOS

34. Windows Today Home/consumer market Home/consumer market –Windows 95 –Windows 98 –Windows Millennium Edition (ME) Corporate market Corporate market –Windows NT –Windows 2000 Windows XP Windows XP Pocket computers and Internet appliances Pocket computers and Internet appliances –Windows CE

35. What are the prominent features of Windows?

36. Prominent feature of Windows: GUI On-screen pictures On-screen pictures –Icons –Menus »Pull down »Pop up –Click to activate a command or function Fast Fast Easy Easy Intuitive Intuitive

37. Windows 95 and 98 Self-contained OS Self-contained OS DOS commands still available DOS commands still available Start programs by Start programs by –Start button –Double clicking the icon Task bar permits movement between open programs Task bar permits movement between open programs Long file names up to 255 characters Long file names up to 255 characters Plug and play Plug and play Object linking and embedding (OLE) Object linking and embedding (OLE)

38. Windows 98 Additions Internet / intranet browsing Internet / intranet browsing Support for DVD and additional multimedia components Support for DVD and additional multimedia components Support for large hard drives Support for large hard drives TV viewer and broadcast ability TV viewer and broadcast ability Wizards / Help Assistant Wizards / Help Assistant

39. Improved Windows Features Backup Backup Interfaces with other software Interfaces with other software Networking features Networking features Security Security Dr. Watson Dr. Watson

40. Windows Helps reduce the cost of owning and maintaining a PC

41. Windows ME Millennium Edition Multimedia support -- Windows Media Player 7 Jukebox Jukebox –Record music CDs as digital files Windows Movie Maker Windows Movie Maker –Basic video editing Windows Image Acquisition Windows Image Acquisition –Scanner and digital camera

42. Windows ME Millennium Edition Reliability Features Reliability Features –System File Protection –AutoUpdate –System Restore Help Center Help Center Home Network Support Home Network Support –Wizard for connecting multiple computers and peripherals –Multiple users can share a single Internet connection

43. Windows NT New Technology Engineered for stability Engineered for stability Strong security Strong security Versions Versions –NT Workstation –NT Server Drawbacks Drawbacks –Lacks support for older Windows and MS-DOS software and hardware –Complex to learn and use –Requires more memory and processing power

44. Windows 2000 Stability features Stability features Security features Security features Uses simple approach to hardware setup from Windows 98 Uses simple approach to hardware setup from Windows 98 Versions Versions –Windows 2000 Professional for individual users –Windows 2000 for network servers Was intended for both the corporate and home use, replacing Win NT and Win 98 Was intended for both the corporate and home use, replacing Win NT and Win 98

45. Windows 2000 Complex Complex Heavy demand for computer resources Heavy demand for computer resources Improvements over windows NT Improvements over windows NT –Maintains user preferences –Self-healing applications software –Supports Windows 98 file structure –Uses plug and play –Provides improved support for laptops

46. Windows XP Extends Windows ME and provides a more stable environment Extends Windows ME and provides a more stable environment Two categories Two categories –Network server »3 versions based upon network complexity –Desktop computer »2 versions Professional Client Professional Client Personal Client Personal Client

47. Windows CE Consumer Electronics Where used Embedded systems Embedded systems –Industrial controllers –Robots –Office equipment –Cameras –Telephones –Home entertainment devices –Automobile navigation systems Pocket PC Pocket PC Internet appliance market Internet appliance market

48. Windows CE Consumer Electronics Subset of Windows Less memory Less memory Smaller screens Smaller screens Little or no file storage Little or no file storage Provides Internet connectivity Provides Internet connectivity

49. Mac OS First commercially successful GUI (1984) First commercially successful GUI (1984) Served as a model to other GUI systems Served as a model to other GUI systems

50. UNIX Supports Supports –Multi-user –Time-sharing Character-based system Character-based system Command-line interface Command-line interface Runs on various processors and many types of computers Runs on various processors and many types of computers Primary OS used on Internet servers Primary OS used on Internet servers

51. LINUX UNIX-like OS UNIX-like OS Open-source software Open-source software –Download it free –Make changes –Distribute copies –Restriction – any changes must be freely available to the public PC Setup PC Setup –PC comes with Windows installed –Install LINUX in a dual-boot configuration

52. LINUX Advantages over Windows Advantages over Windows –Extremely stable –Internet support –Reinstallation is simpler Disadvantage Disadvantage –Scarcity of applications

53. Large Computers Used by many people at once Used by many people at once OS works “behind the scenes” so users can share resources (hardware & software) OS works “behind the scenes” so users can share resources (hardware & software) OS must control OS must control –Who gets access to resources –What keeps the programs from different users from getting mixed up with one another

54. Sharing Memory Program must be in memory to be executed Program must be in memory to be executed Problems Problems –Programs compete for space –May have a very large program –Memory space for each program must not overlap

55. Memory Management The process of providing separate memory space to programs The process of providing separate memory space to programs Memory Protection keeps one program from interfering with another Memory Protection keeps one program from interfering with another

56. Sharing Storage Several users need to access the same disk pack Several users need to access the same disk pack –One wants to write –Another wants to read OS keeps track of the I/O requests OS keeps track of the I/O requests OS processes I/O requests in order received OS processes I/O requests in order received

57. Utility Programs Come with System Software Come with System Software Handle special needs Handle special needs Perform secondary chores Perform secondary chores Do not need to be memory resident Do not need to be memory resident

58. Functions of Utility programs File manager – provide access to lists of stored files File manager – provide access to lists of stored files Backup and Restore – make duplicate copies of important files and return the copy to the hard drive if needed Backup and Restore – make duplicate copies of important files and return the copy to the hard drive if needed File compression – reduces the amount of disk space required by a file File compression – reduces the amount of disk space required by a file Disk defragmenter – reorganize files so they are stored contiguously on disk providing for faster access Disk defragmenter – reorganize files so they are stored contiguously on disk providing for faster access Device drivers – convert operating system instructions into commands that are known to a specific device Device drivers – convert operating system instructions into commands that are known to a specific device

59. Are all operating systems the same? Features and functions. Features and functions. Advantages and benefits. Advantages and benefits. From Personal Computers to Mainframes?

60. Summary Operating systems are the foundation of a computer operation. Operating systems benefits include better resource utilization, better system performance, gains in cost- effectiveness and better overall management of the entire system. Without operating systems with advanced features and functions, computing would still be in its very early stages.