Lecture Notes: Operating Systems

Introduction to Operating Systems

• Purpose: Interface between user and hardware.
• Function: Allows user interaction with application software to accomplish tasks.

Interaction with Hardware

• Process: Input data → Process data → Output results.
• Role of OS: Facilitates user interaction with hardware via software.

Application Software and User Interface

• User Interface: Common and familiar UI for applications.
• OS Role: Provides platform for application software to run.
• Utility Programs: Built-in programs for maintenance (e.g., encryption, compression, defragmentation).

Memory and File Management

• Memory Management: Loading programs into memory, executing, managing data.
• File Management: Storing and loading files; saving data to prevent loss.

Device Drivers and Peripherals

• Device Drivers: Translate OS instructions for hardware.

Interrupt Handling

• Definition: Device requires processor's attention (e.g., power failure, key press).
• Importance: Critical for OS to handle efficiently.

User Interfaces

1. Graphical User Interface (GUI)

   • Features: Windows, icons, menus, pointers (WIMP).
   • Advantages: Visual, interactive, intuitive for beginners.
   • Input: Optimized for mouse/touch gestures.

2. Command Line Interface (CLI)

   • Features: Text-heavy, resource-efficient.
   • Advantages: Slim, fast, more commands.
   • Users: Advanced users for technical tasks, script automation.

3. Menu Driven Interface

   • Examples: Cash points, chip and pin devices.
   • Operation: Successive menus, single choice.
   • Input: Button/keypad interaction.

4. Natural Language Interface

   • Operation: Voice commands in natural language.
   • Examples: Siri, Cortana, Google Assistant, Alexa.
   • Challenges: Reliability improving with technology advancement.

Conclusion

• Summary: Recap of operating system functions and user interfaces.
• Note: Importance of taking notes to reinforce learning.