Concept Origin: The multi-programmed OS concept came first.
Definition: Loads as many processes as possible into RAM.
Execution:
Generally non-preemptive.
CPU executes each process completely before moving to the next.
Reduces CPU idle time.
Example: 10 students, each with 5 questions. The CPU (teacher) solves all 5 questions for student 1 before moving to student 2, and so on.
CPU Idle Reduction: When a process requires I/O operations, another process is given to the CPU.
Multi-tasking (Time-sharing) Operating System
Definition: Preemptive. The CPU is assigned to each process for a fixed time slice.
Execution:
The CPU switches between processes after the allotted time, even if the process is not completed.
Example: 10 students, each with 5 questions. The CPU (teacher) solves 2 questions for student 1, then 2 questions for student 2, and so on, before looping back to student 1.
Advantages:
Reduced Idleness: CPU always has processes ready to execute.
Improved Response Time: Faster initial response to all processes.
Real-time Use: The multi-tasking OS is used in real-time systems like laptops.
Algorithms: Includes algorithms like round robin.
Differences & Key Points
Multi-programmed OS:
Executes each process completely before moving to the next.
Lower emphasis on responsiveness.
Multi-tasking OS:
Preemptive switching between processes.
Higher responsiveness.
Minimizes CPU idleness.
Conclusion
Different systems and their advantages.
Refer to other videos for detailed algorithms like round robin.