Operating System Tutorial

Operating System Fundamentals

• Definition: An Operating System (OS) is system software that acts as an interface between computer hardware and the user, managing resources and providing common services for applications.
• Core Components of a Computer System:
  • Hardware: Physical components (CPU, memory, disks, peripherals).
  • System Software: Low-level software (OS, compilers, assemblers) that interacts directly with hardware.
  • Application Software: User-facing programs (browsers, word processors, games).
  • Users: Individuals interacting with the system.
• Key OS Functions:
  • Process and task scheduling.
  • Memory management (main and secondary storage).
  • File and I/O device management.
  • Security, error detection, and network management.
• Historical Milestones:
  • 1956: First OS created by General Motors for the IBM 704.
  • 1960s: Development of Unix (originally MULTICS) by MIT, AT&T Bell Labs, and GE.
  • 1981: Microsoft acquired QDOS, rebranding it as MS-DOS.
  • 1991: Linux first released by Linus Torvalds.
  • 1995: Windows 95 released as a consumer-oriented GUI OS.
• Popular Operating Systems:
  • Windows: Commercial OS developed by Microsoft.
  • Linux: Unix-based, open-source OS with numerous variants (Ubuntu, Fedora, etc.).
  • macOS/iOS: Unix-based systems developed by Apple.
  • Android: Mobile OS based on the Linux kernel.
• Technical Topics Covered:
  • Process Management: States, scheduling algorithms (FCFS, SJF, Round Robin, etc.), synchronization, and deadlock handling.
  • Memory Management: Paging, segmentation, virtual memory, and allocation algorithms.
  • Storage/File Systems: Disk scheduling, file attributes, and directory structures.
  • I/O Systems: Hardware/software interfaces and Direct Memory Access (DMA).
  • OS Types: Batch, multiprogramming, multitasking, distributed, real-time, and embedded systems.