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© 2001 Business & Information Systems 2/e2 Chapter 5 Information System Software

© 2001 Business & Information Systems 2/e3 Our Agenda Software Concepts Application Software System Software Software Development

© 2001 Business & Information Systems 2/e4 Learning Objectives Explain in detail what programs and software are. Identify the common application software used in information systems. Describe some ways users can tell an operating system what to do. Describe some of the capabilities of operating systems.

© 2001 Business & Information Systems 2/e5 Learning Objectives (cont’d.) Explain the main differences between the five types, or generations, of programming languages. Explain the difference between object- oriented programming and traditional programming, and identify one traditional and one object-oriented programming language.

© 2001 Business & Information Systems 2/e6 Learning Objectives (cont’d.) Identify programming languages that are used with the Internet and the World Wide Web.

© 2001 Business & Information Systems 2/e7 Software Concepts Information System Software

© 2001 Business & Information Systems 2/e8 Software Concepts A program is a set of instructions that tells the computer what to do. Software can be a single program or a group of programs needed to perform several functions. Simple programs may have a few hundred instructions (lines of code) though most have many more (several million).

© 2001 Business & Information Systems 2/e9 Application Software Information System Software

© 2001 Business & Information Systems 2/e10 Individual Application Software Word processing Spreadsheet Graphics Database Browser

© 2001 Business & Information Systems 2/e11 Workgroup Application Software Groupware software Information sharing software Electronic conferencing software

© 2001 Business & Information Systems 2/e12 Other Application Software Organizational application software Generally organization specific Interorganizational application software Electronic Data Interchange (EDI) Generally common to the participating organizations

© 2001 Business & Information Systems 2/e13 System Software Information System Software

© 2001 Business & Information Systems 2/e14 Operating System Concepts An operating system is a group of programs that manages the operation of the computer. Three functions of an operating system Process management Resource management Data management

© 2001 Business & Information Systems 2/e15 Operating System Concepts (cont’d.) Organization of an operating system Most operating system programs are stored in secondary storage. One operating system program is stored in a section of primary storage. It goes by various names – kernel – but generically called the “supervisor”. The supervisor controls all activity in primary storage.

© 2001 Business & Information Systems 2/e16 Using an Operating System Starting the computer is called booting which transfers the “supervisor” from secondary storage to primary storage. Connecting to a network or other multi- user environment is called logging in. Detaching from a network is called logging out.

© 2001 Business & Information Systems 2/e17 Elements of an Operating System User interface is the visual link between the user and the software. Small pictures on the screen are icons. Graphical User Interface (GUI) uses Buttons Icons Menus Dialog boxes

© 2001 Business & Information Systems 2/e18 Capabilities of Operating Systems Multitasking is appearing to execute more than one program at a time, though the CPU can execute instructions from only one program at a time.

© 2001 Business & Information Systems 2/e19 Capabilities of Operating Systems (cont’d.) Multi-user or Multiple-user programs permit more than one person to use the program, and data, at a time. One technique that is used with multiple-user operating systems is time sharing. With this technique, the users are each allocated a small amount of time by the operating system.

© 2001 Business & Information Systems 2/e20 Capabilities of Operating Systems (cont’d.) Two types of operating systems Batch operating systems where the first program is executed and all data processed before moving to the second program. Interactive operating systems allow user interaction as the program executes. Most personal computer operating systems permit user interaction.

© 2001 Business & Information Systems 2/e21 Capabilities of Operating Systems (cont’d.) Virtual memory is supplemental primary storage (RAM) or “real” memory where the programs are too big for primary storage. It is created on a secondary storage device, usually the hard drive, and is generally temporary in nature.

© 2001 Business & Information Systems 2/e22 Capabilities of Operating Systems (cont’d.) Virtual memory operating systems execute large programs by dividing the program into parts and transferring the necessary parts of the program from secondary storage to primary storage as needed. The transfer process does not require any action by the user.

© 2001 Business & Information Systems 2/e23 Personal Computer Common Operating Systems Microsoft Windows Microsoft DOS (and others) IBM OS/2 Apple Mac OS UNIX Linux

© 2001 Business & Information Systems 2/e24 Multi-User Computer Common Operating Systems IBM OS/390 Hewlett Packard MPE (MultiProgramming Executive) UNIX Network Operating Systems Novell Netware Windows 2000 Server

© 2001 Business & Information Systems 2/e25 Other System Software Utility programs Sort utility – rearranges data in a specified order Merge utility – merges two files into one Print utility – prints the contents of a file Copy utility – copies data from one device to another

© 2001 Business & Information Systems 2/e26 Other System Software (cont’d.) Communications software – used for communications between computers. Database management systems – used for managing databases. Software development software – software used to develop software.

© 2001 Business & Information Systems 2/e27 Software Development Information System Software

© 2001 Business & Information Systems 2/e28 Programming Language Concepts What is a programming language? Why are there so many programming languages? How do you select a programming language? What are the types of programming languages?

© 2001 Business & Information Systems 2/e29 What is a Programming Language English is a natural language. It has words, symbols and grammatical rules. A programming language also has words, symbols and rules of grammar. The grammatical rules are called syntax. Each programming language has a different set of syntax rules.

© 2001 Business & Information Systems 2/e30 Why Are There So Many Programming Languages Programming languages have evolved over time as better ways have been developed to design them. Different programming languages are designed for different types of programs. First programs were developed in the 1950s.

© 2001 Business & Information Systems 2/e31 How Do You Select a Programming Language Is it designed for the type of program that needs to be written? Is it available on the computer being used? Are trained programmers available? Is it easy to write programs in the language? Is the language efficient when the program is executed?

© 2001 Business & Information Systems 2/e32 What Are the Types of Programming Languages First Generation Languages Second Generation Languages Third Generation Languages Fourth Generation Languages Fifth Generation Languages

© 2001 Business & Information Systems 2/e33 First Generation Languages Machine language Operation code – such as addition or subtraction. Operands – that identify the data to be processed. Machine language is machine dependent as it is the only language the computer can understand. Very efficient code but very difficult to write.

© 2001 Business & Information Systems 2/e34 Second Generation Languages Assembly languages Symbolic operation codes replaced binary operation codes. Assembly language programs needed to be “assembled” for execution by the computer. Each assembly language instruction is translated into one machine language instruction. Very efficient code and easier to write.

© 2001 Business & Information Systems 2/e35 Third Generation Languages Closer to English but included simple mathematical notation. Programs written in source code which must be translated into machine language programs called object code. The translation of source code to object code is accomplished by a machine language system program called a compiler.

© 2001 Business & Information Systems 2/e36 Third Generation Languages (cont’d.) Alternative to compilation is interpretation which is accomplished by a system program called an interpreter. Common third generation languages FORTRAN COBOL C and C++ Visual Basic

© 2001 Business & Information Systems 2/e37 Fourth Generation Languages A high level language (4GL) that requires fewer instructions to accomplish than a third generation language. Used with databases Query languages Report generators Forms designers Application generators

© 2001 Business & Information Systems 2/e38 Fifth Generation Languages Though no clear definition at present, natural language programs generally can be interpreted and executed by the computer with no other action by the user than stating their question. Limited capabilities at present.

© 2001 Business & Information Systems 2/e39 Programming Languages Two broad groups Traditional programming languages Sequences of instructions First, second and some third generation languages Object-oriented languages Objects are created rather than sequences of instructions Some third generation, and fourth and fifth generation languages

© 2001 Business & Information Systems 2/e40 Traditional Programming Languages FORTRAN FORmula TRANslation. Developed at IBM in the mid-1950s. Designed for scientific and mathematical applications by scientists and engineers.

© 2001 Business & Information Systems 2/e41 Traditional Programming Languages (cont’d.) COBOL COmmon Business Oriented Language. Developed in Designed to be common to many different computers. Typically used for business applications.

© 2001 Business & Information Systems 2/e42 Traditional Programming Languages (cont’d.) BASIC Beginner’s All-purpose Symbolic Instruction Code. Developed at Dartmouth College in mid 1960s. Developed as a simple language for students to write programs with which they could interact through terminals.

© 2001 Business & Information Systems 2/e43 Traditional Programming Languages (cont’d.) C Developed by Bell Laboratories in the early 1970s. Provides control and efficiency of assembly language while having third generation language features. Often used for system programs. UNIX is written in C.

© 2001 Business & Information Systems 2/e44 Object-Oriented Programming Languages Smalltalk First object-oriented language. Developed by Xerox in mid-1970s. Still in use on some computers.

© 2001 Business & Information Systems 2/e45 Object-Oriented Programming Languages (cont’d.) C++ It is C language with additional features. Widely used for developing system and application software. Graphical user interfaces can be developed easily with visual programming tools.

© 2001 Business & Information Systems 2/e46 Special Programming Languages HTML HyperText Markup Language. Used on the Internet and the World Wide Web (WWW). Web page developer puts brief codes called tags in the page to indicate how the page should be formatted.

© 2001 Business & Information Systems 2/e47 Special Programming Languages (cont’d.) XML Extensible Markup Language. A language for defining other languages.

© 2001 Business & Information Systems 2/e48 Special Programming Languages (cont’d.) JAVA An object-oriented language similar to C++ that allows a web page developer to create programs for applications, called applets that can be used through a browser. Objective of JAVA developers is that it be machine, platform and operating system independent.

© 2001 Business & Information Systems 2/e49 Information Systems Software Key Terms

© 2001 Business & Information Systems 2/e50 Key Terms Assembler Assembly Language BASIC Booting Browser Button C C++ COBOL Command Compiler Database Software Dialog Box Electronic Conferencing Software Electronic Messaging Software FORTRAN

© 2001 Business & Information Systems 2/e51 Key Terms (cont’d.) Fourth-Generation Language (4GL) Graphical User Interface (GUI) Graphics Software Groupware HTML Icon Information Sharing Software Interpreter Java Menu Multitasking Network Operating System (NOS) Object

© 2001 Business & Information Systems 2/e52 Key Terms (cont’d.) Object-Oriented Programming Operating Environment Page Programmer Programming Programming Language Prompt Spreadsheet Software Time-Sharing User Interface Utility Program Virtual Memory Window Word Processing Software XML

© 2001 Business & Information Systems 2/e53 Summary Software Concepts Application Software System Software Software Development

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