E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins MANAGINGINFORMATIONTECHNOLOGY FIFTH EDITION CHAPTER 3 C OMPUTER S OFTWARE

© 2005 Pearson Prentice-Hall Chapter Machine language (1GL) Each instruction must be expressed in unique form for a particular computer Complete program consists of thousands of instructions Programming was tedious, time-consuming process 2.Assembly languages (2GL)  Use computer itself to perform many aspects of the programming  Create a machine language program as output, that is then used by the computer’s control unit First and Second Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 53

© 2005 Pearson Prentice-Hall Chapter First and Second Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 53 Figure 3.1 Assembler Translation Process SOURCE PROGRAM OBJECT PROGRAM (which can be directly executed on computer)

© 2005 Pearson Prentice-Hall Chapter Procedural Languages (3GL) Generally are machine independent. Express a step-by-step procedure developed by programmer Must be compiled or interpreted (translated into machine language) Include FORTRAN, COBOL, BASIC, PL/1, PASCAL, ADA, and C Third and Fourth Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 53

© 2005 Pearson Prentice-Hall Chapter Page 54 Figure 3.2 Compiling and Running a Procedural Language Program SOURCE PROGRAM OBJECT PROGRAM

© 2005 Pearson Prentice-Hall Chapter Page 54 Figure 3.3 Interpreting and Running an Interpretive Language Program SOURCE PROGRAM

© 2005 Pearson Prentice-Hall Chapter Nonprocedural Languages (4GL) Also referred to as productivity languages Use more English-like statements for program instructions Easier to use, write, and less error-prone Use a built-in interpreter to convert to machine language Take much longer to execute than 3GLs Include FOCUS, CA-Ramis, IFPS, and SAS Third and Fourth Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 55

© 2005 Pearson Prentice-Hall Chapter Object-Oriented (Visual) Languages 3GLs with some 4GL features Built on idea of embedding procedures (methods) in objects, and putting objects together to create an application Include Smalltalk, C++, Java, and Visual Basic Third and Fourth Generation Languages E VOLUTION OF C OMPUTER P ROGRAMMING Page 55 Figure 3.4 The Software Iceberg

© 2005 Pearson Prentice-Hall Chapter Applications software 2.Support software Page 56 K EY T YPES OF S OFTWARE Figure 3.4 The Software Iceberg

© 2005 Pearson Prentice-Hall Chapter Programs written to accomplish particular tasks Diverse … some general-purpose and some specific Examples include:  General ledger accounting  Portfolio management  Sales forecasting  Material requirements planning (MRP)  Electronic mail  Desktop publishing Page A PPLICATIONS S OFTWARE

© 2005 Pearson Prentice-Hall Chapter Peachtree Accounting Complete  Commercial accounting package for smaller businesses  Includes general ledger, accounts receivable, accounts payable, inventory, payroll, time and billing, job costing, fixed asset accounting, and analysis and reporting tools  $300 for single-user version Page 58 A PPLICATIONS S OFTWARE Examples of Applications Packages

© 2005 Pearson Prentice-Hall Chapter Page 58 Figure 3.5 “My Business Page” from Peachtree Complete Accounting

© 2005 Pearson Prentice-Hall Chapter Word processing Spreadsheets Presentation graphics Electronic mail and groupware Database management systems Desktop publishing Web browsers Statistical packages Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Word processing  Used to create documents for printing  Most popular is Microsoft Word  Others are Corel WordPerfect, Lotus Word Pro, and Sun’s StarOffice Writer  All employ WYSIWYG Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Spreadsheets  Used to create applications that fit a row-column format  Most popular is Microsoft Excel  Others are Lotus and Corel Quattro Pro  All employ rows, columns, cells, formulas, “what-if” analysis Page 60 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Page 61 Figure 3.6 Microsoft Excel Spreadsheet

© 2005 Pearson Prentice-Hall Chapter Database Management Systems  Used to create databases similar to those on larger machines  Most popular is Microsoft Access  Others are FileMaker Pro, Corel Paradox, and Lotus Approach  All employ a relational data model Page 61 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Presentation Graphics  Used to create largely textual business presentations  Most popular is Microsoft PowerPoint  Others are Corel Presentations and Lotus Freelance Graphics  All allow embedding of clip art, photos, graphs, and other media Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter World Wide Web Browsers  Used to access information on the Web  Requires ISP service to link PC to Internet  Create documents for printing  Most popular are Internet Explorer and Netscape Navigator … both free!  Both employ standard hypertext-based approach (way to link text and media objects to each other)  Use pull technology – browser requests a Web page before it is sent to desktop  Use push technology – data sent to client without requesting it (such as ) Page A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Electronic Mail  Preferred way of communicating in business today  Easy to use and precise Groupware  Incorporates and other productivity features, such as calendaring, scheduling, and document sharing Page 63 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Office Suites  Popular software applications bundled together and sold as a single package (suite)  Used for home or office  Most popular is Microsoft Office  Others are Corel WordPerfect Office, Lotus SmartSuite, and Sun StarOffice Page 64 A PPLICATIONS S OFTWARE Personal Productivity Software

© 2005 Pearson Prentice-Hall Chapter Page 64 A PPLICATIONS S OFTWARE Personal Productivity Software Microsoft Office 2003 EditionApplicationsPurposeRetail price Standard Word Excel PowerPoint Outlook Word processing Spreadsheets Presentation graphics , scheduling $399 Small Business Adds: Publisher Desktop publishing $449 Professional Adds: Access Database management $499

© 2005 Pearson Prentice-Hall Chapter User communicates with operating system software to control hardware and software resources Communication made easier with a graphical user interface (GUI) feature Page 66 S UPPORT S OFTWARE The Operating System Operating system – complex program that controls operation of computer hardware and coordinates other software

© 2005 Pearson Prentice-Hall Chapter Page 66 S UPPORT S OFTWARE The Operating System Job Control Language (JCL) – keyed instructions from the computer user to communicate with the operating system

© 2005 Pearson Prentice-Hall Chapter Page S UPPORT S OFTWARE The Operating System Multiprogramming – employed on larger machines to overlap input and output operations with processing time, keeping the CPU busy and speeding up execution Multitasking – similar to multiprogramming, but employed on microcomputers

© 2005 Pearson Prentice-Hall Chapter Virtual Memory  Concerned with management of main memory  Makes it appear more memory available than actually is  Used only on larger computers  Permits multiprogramming to operate more efficiently Page 67 S UPPORT S OFTWARE The Operating System

© 2005 Pearson Prentice-Hall Chapter Page 67 S UPPORT S OFTWARE The Operating System Multiprocessing – work that takes place when two or more CPUs are installed on same computer system

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems  Microcomputers: MS-DOS, PC-DOS, Windows XP  Midrange systems: OS/400  Large systems: VM and MVS Page 68 S UPPORT S OFTWARE The Operating System Proprietary systems – most popular type of operating systems, written for a particular computer hardware configuration

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems  Examples: UNIX and Linux Page 68 S UPPORT S OFTWARE The Operating System Open systems – not tied to any particular computer system or hardware manufacturer – will run on virtually any computer system

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems  Enhanced operating system to allow for sharing disk drives and printers handling server side of client/server applications Page 68 S UPPORT S OFTWARE The Operating System Network operating systems (NOS) – software running on a server that manages network resources and controls the operation of a network

© 2005 Pearson Prentice-Hall Chapter Sources of Operating Systems Major players include: UNIX and Linux Microsoft Windows NT, 2000 Server, 2003 Server Novell NetWare Page 68 S UPPORT S OFTWARE The Operating System Network operating systems (NOS) – software running on a server that manages network resources and controls the operation of a network

© 2005 Pearson Prentice-Hall Chapter Procedural languages (3GL)  Require logical thinking  Entail development of a detailed step-by- step procedure  Can be developed using structured programming Page 69 S UPPORT S OFTWARE Third Generation Languages

© 2005 Pearson Prentice-Hall Chapter Advantages:  Program logic easier to follow  Maintenance and correction easier and faster  Do not use GO TO logic Page 70 S UPPORT S OFTWARE Third Generation Languages Structured programs – divided into modules, where each has one entry and one exit point

© 2005 Pearson Prentice-Hall Chapter Page 70 S UPPORT S OFTWARE Third Generation Languages Table 3.1 Stages in the Program Development Process

© 2005 Pearson Prentice-Hall Chapter Most popular procedural languages:  BASIC  C  COBOL Page S UPPORT S OFTWARE Third Generation Languages

© 2005 Pearson Prentice-Hall Chapter Page 71 Figure 3.9 BASIC Program

© 2005 Pearson Prentice-Hall Chapter Page 72 Figure 3.10 C Program

© 2005 Pearson Prentice-Hall Chapter Page 73 Figure 3.11 COBOL Program

© 2005 Pearson Prentice-Hall Chapter Page 73 Figure 3.11 COBOL Program

© 2005 Pearson Prentice-Hall Chapter Page 74 Figure 3.11 COBOL Program

© 2005 Pearson Prentice-Hall Chapter Other procedural languages:  FORTRAN  PL/1  PASCAL  ADA Page 74 S UPPORT S OFTWARE Third Generation Languages

© 2005 Pearson Prentice-Hall Chapter Nonprocedural languages:  Use very high-level instructions  Require fewer instructions  Easier to write, modify, understand  Example: FOCUS Page 75 S UPPORT S OFTWARE Fourth Generation Languages

© 2005 Pearson Prentice-Hall Chapter Page 76 Figure 3.12 FOCUS Program and Output

© 2005 Pearson Prentice-Hall Chapter Most popular:  HTML: used to create Web pages  XML: used to facilitate data interchange among Web applications Page S UPPORT S OFTWARE Markup Languages

© 2005 Pearson Prentice-Hall Chapter Requires more computing power Has built-in GUI Neither 3GL nor 4GL … new paradigm Creates objects only once and stores for reuse Object examples:  Text box, check box, entity in an organization Languages:  Smalltalk, C++, Java, Visual Basic.NET Page 78 S UPPORT S OFTWARE Object-Oriented Programming

© 2005 Pearson Prentice-Hall Chapter Page 80 Figure 3.13A Visual Basic Program

© 2005 Pearson Prentice-Hall Chapter Page 81 Figure 3.13B Visual Basic Screen Layout

© 2005 Pearson Prentice-Hall Chapter HTML Server-side programming languages:  Perl  Java Servlets and Java Server Pages  Microsoft Active Server Pages (ASP, ASP.NET)  ColdFusion Page S UPPORT S OFTWARE Languages for Developing Web Applications

© 2005 Pearson Prentice-Hall Chapter Page 84 Figure 3.17 Grocery Store HTML Form

© 2005 Pearson Prentice-Hall Chapter Page 85 Figure 3.17 HTML and ASP.NET code to accompany Grocery Store HTML Form

© 2005 Pearson Prentice-Hall Chapter Page 86 Figure 3.18 Program to Process Data from Grocery Store HTML Form

© 2005 Pearson Prentice-Hall Chapter Page 86 Figure 3.19 Grocery Store Confirmation Web Page

© 2005 Pearson Prentice-Hall Chapter Page 86 Figure 3.19 Code to Generate Confirmation Web Page

© 2005 Pearson Prentice-Hall Chapter DBMS – support software used to create, manage, and protect organizational data Database – shared collection of logically related data organized to meet organizational needs Relational DBMS  Most common type  Data arranged in simple tables  Records related by storing common data in each associated table  Examples: Microsoft Access and SQL Server, Paradox, DB2, and Ingres Page 87 S UPPORT S OFTWARE Database Management Systems

© 2005 Pearson Prentice-Hall Chapter Sequential – arranges records physically adjacent and in order by some (usually unique) sort key Direct – uses key for records placed so that they are rapidly accessed from DASDs Page 88 S UPPORT S OFTWARE File Organization Figure 3.20 File Organizations

© 2005 Pearson Prentice-Hall Chapter S UPPORT S OFTWARE Indexed  Compromise between sequential and direct  Record keys only arranged in sequence in a separate table, along with location of rest of data associated with that key  Popular types include ISAM and VSAM Page 88 File Organization Figure 3.20 File Organizations

© 2005 Pearson Prentice-Hall Chapter Page 89 Figure 3.21 Relationship Schemes Relational DBMSs use this scheme

© 2005 Pearson Prentice-Hall Chapter  Growth slower than anticipated  Radically changed nature of systems analyst and programmer jobs Page 88 S UPPORT S OFTWARE CASE Tools Computer-aided software engineering (CASE) – collection of software tools to help automate all phases of the software development life cycle

© 2005 Pearson Prentice-Hall Chapter Large computers  need to control workstations and terminals  Example software: IBM’s CICS, TSO, and CMS LANs and WANs  Need to connect to the Internet  Web browsers  Telenet  File Transfer Protocol (FTP) Page S UPPORT S OFTWARE Communications Interface Software

© 2005 Pearson Prentice-Hall Chapter More complexity of hardware/software arrangements Less concern with machine efficiency More purchased applications More programming using object-oriented and visual languages More emphasis on applications that run on intranets and the Internet More user development More use of personal productivity software Page T HE C HANGING N ATURE OF S OFTWARE

© 2005 Pearson Prentice-Hall Chapter More complexity of hardware/software arrangements Less concern with machine efficiency More purchased applications More programming using object-oriented and visual languages More emphasis on applications that run on intranets and the Internet Page 92 T HE S OFTWARE C OMPONENT OF THE I NFORMATION S YSTEMS I NDUSTRY