1. Chapter 5 Information Systems in Business Software

2. Software: Instructions to the Computer
A computer program is a series of instructions to a computer to execute any and all processes.
Computers only “understand” instructions consisting of electrical signals alternating between two states.

3. Programming Languages
Abbreviated forms of instructions that translate into machine language
New programming languages make programming easier for people who are not necessarily hardware experts

4. Machine Languages (ML)
Only languages computers can directly interpret to carry out instructions
ML coding: time-consuming and error-prone
ML programmers: concerned with hardware details
Every computer or family of computers has its own ML; each is machine-dependent.

5. Assembly Languages
More English-like; codes shorter than machine languages
Assembler translates into machine language
Advantages of machine or assembly languages
Programmer in control of hardware
Programs written in low-level languages run more efficiently.

7. Procedural Languages
Third-generation (procedural) languages are more English-like than assembly languages.
Relatively easy to learn, write, and debug.
FORTRAN, COBOL, BASIC

8. Fourth Generation Languages (4GL)
4GLs are more English-like than procedural languages.
Easy to learn and use; shorter application development time.
PowerBuilder, FOCUS, NOMAD, and RAMIS

9. Levels of programming Language:
9-17

10. Visual Programming
Languages that let programmers create field windows, scroll-down menus, click buttons, etc., by choosing from a palette
Appropriate code written automatically
Accelerates work
Microsoft’s Visual Basic

11. Object-Oriented Programming (OOP)
Emphasis on the objects involved in the task, not on the procedure
An object encapsulates a data set with the code that is used to operate on it
Standardized programming modules can be reused

12. Advantages of Object-Oriented Programming over Procedural Languages

13. Advantages and disadvantages of higher-level programming languages

14. Application Software vs. System Software
Application: a program developed to address a specific business need; software for development of such programs.
System: programs designed to carry out general routine operations, such as loading, copying, or deleting a file.

15. Application Software Custom-Designed Applications Advantages:
Meeting the organization’s needs exactly
In-house developers are sensitive to the organizational culture
Disadvantages:
High cost
Production schedule subject to long delays
Incompatible with other organizations’ systems

16. Advantages and disadvantages of tailored applications

17. Packaged Software Advantages:
Low cost
High quality
Vendor support
Immediate availability
Often tested at user sites (alpha sites and beta sites) before the final version is released

18. Advantages and disadvantages
of packaged software

19. System Software
Manages computer resources and performs routine tasks not specific to any application
Copying and pasting sections and files
Printing documents
Allocating memory
Developed to partner
with application
software

20. Operating Systems (O/S)
Most important system software
Developed for a certain microprocessor or microprocessors
Plays the role of “traffic cop” or the “boss” of computer resources

21. The operating system mediates between applications and the computer, and controls peripheral devices.

22. Operating System Functions
Systems Management
User Interface
Memory Allocation
Multitasking, Multiprogramming, and Multiprocessing
Times and Statistics
Increasing Services from O/Ss

23. MICROCOMPUTER OPERATING SYSTEMS
FEATURES
32-bit operating system; GUI; Multitasking.
Networking
32-bit operating system not limited to Intel chips.
Multitasking; Multiprocessing; Networking
32-bit. Developed for IBM PS/2. Multitasking;
Paired-down for handheld computers, wireless communication devices
Windows 98 & 95
Windows NT Me, 2000&XP
Windows CE
OS/2

24. MICROCOMPUTER OPERATING SYSTEMS
FEATURES
For powerful Microcomputers, Workstations,
Minicomputers. Multitasking; Multi-user Processing; Networking. Portable to various Computer Platforms
Unix
Linux
Free, reliable alternative to Unix, Windows. Runs on many Platforms
Mac OS
For Macintosh computers. Multitasking.
Powerful Graphics; Multimedia
DOS
For IBM (PC-DOS) and PC (MS-DOS).
Program Memory: 640K

25. Popular Operating System

26. Compilers and Interpreters
Scans source code and translates into object code
Generates error message and does not compile when an error is found
Allows users to save programs in object code
Interpreter
Checks one statement at a time
Changes error-free statements into ML
Generates an error message for errors

27. Data Communication Programs
Controls and supports data communication activities in a network
Setting up rules that govern transmission and reception of data
Connecting and disconnecting communication links
Assigning priorities among terminals in a network
Detecting and correcting transmission errors

28. Proprietary vs. Open Source
Proprietary O/S: limited to using applications compatible with it
Open O/S: compatible with virtually all applications.
Completely open O/S does not exist
Some O/Ss (e.g., Unix) are said to be nonproprietary, but it is still impossible to run many applications on different versions of such O/Ss.

29. Sample results of software evaluation
(5 is the highest score.)