The Operating System

1. The Operating System

2. What is an Operating System? • The software which makes it possible for you to use your computer • The software which starts up when you switch on your computer • The software which lets you log on to a network

3. Where is the operating system stored? • A small part is stored in ROM - the part which tells the machine what to do when it is first switched on (Bootstrap Loader) • The rest is stored on disk and loaded into RAM once the computer starts up • Some is stored on disk and only loaded into RAM when it is needed (Utilities)

4. Single user operating system • Interprets commands • Controls the filing system • Manages memory • Monitors input and output devices • Process Management

5. Network Operating System tasks • Data Integrity • Security and multi-user access • Encryption

6. Operating System Utilities • Defragmentation • Virus Scanning • Disk repair • File compression • Find facility • Translators (interpreters and compilers)

7. Defragmentation

8. Virus Checker

9. Disk Repair

10. File Compression

11. File Finder

12. Compilers and Interpreters Interpreter For Counter = 1 To 100000 For counter2 = 1 To 10000 Next counter2 Next Counter Print "done" Compiler

13. Types of Operating System • Multi user • Deals with several users simultaneously • Real Time • Reacts immediately to events • Interactive • Responds directly to users commands

14. The Parts of an Operating System • Basic Input Output System • File and Memory manager • Command Language Interpreter • Graphical User Interface

15. Hardware

16. Basic Input Output System Hardware (BIOS)

17. File and Memory Manager Basic Input Output System Hardware (BIOS)

18. Command Language Interpreter File and Memory Manager Basic Input Output System Hardware (BIOS)

19. Graphical User Interface Command Language Interpreter File and Memory Manager Basic Input Output System Hardware (BIOS)