1. 3/5/2002e-business and Information Systems1 Introduction Computer System Hardware Software HW Kernel/OS API Application Programs SW

2. 3/5/2002e-business and Information Systems2 Software/Program Software or program is a set of computer instructions that achieve specific tasks. written in a specific language

3. 3/5/2002e-business and Information Systems3 Programming Language Evolution First Generation Language – machine language Second Generation Language – assembly language Third Generation Language – high level language C C++ BASIC COBOL …….. Programmer friendly

4. 3/5/2002e-business and Information Systems4 Application Programming Languages C : operating system C++ : applications BASIC : easy to learn COBOL : business applications

5. 3/5/2002e-business and Information Systems5 Application Programs Examples MS Word Netscape Web Browser MS PowerPoint

6. 3/5/2002e-business and Information Systems6 SW/Program/Code Source code – text/ASCII Object code - binary Machine code - binary

7. 3/5/2002e-business and Information Systems7 Compiler & Linker CompilerLinker Source Code Object Code Executable Code Readable by human Executable by machine Machine code Text Other Object Codes

8. 3/5/2002e-business and Information Systems8 Execution User Kernel/OS Executable Code 1 2 3

9. 3/5/2002e-business and Information Systems9 Compiling and Linking Errors CompilerLinker Source Code Object Code Executable Code Syntax Errors: Detected by compiler Missing objects: Detected by linker Machine code Text Other Object Codes

10. 3/5/2002e-business and Information Systems10 Execution and Logical Errors User Kernel/OS Executable Code 1 2 3 Run-time error: Detected by OS Logical error: Detected by user, tester, or programmer