Chapter 1 Introduction to OS
by CHA KIA VUI
1. Hard and Soft Real Time Tasks
1.1. Hard real-time task
1.1.1. One that must meet its deadline
1.1.2. Otherwise it will cause unacceptable damage or a fatal error to the system
1.2. Soft real-time task
1.2.1. Has an associated deadline that is desirable but not mandatory
1.2.2. it still makes sense to schedule and complete the task even if it has passed its deadline
2. Main Objectives of an OS
2.1. Convenience
2.2. Efficiency
2.3. Ability to evolve
3. Evolution of Operating System
3.1. Reason
3.1.1. Hardware Upgrades
3.1.2. New services
3.1.3. New types of hardware
3.1.4. Fixes
3.2. Stages include
3.2.1. Serial Processing
3.2.2. Simple batch Systems
3.2.3. Multiprogrammed Batch Systems
3.2.4. Time Sharing Systems
4. Characteristics of Real Time Systems
4.1. Determinism
4.2. Responsiveness
4.3. User control
4.4. Reliability
4.5. Fail-soft operation
5. Parallel Systems
5.1. Advantages of parallel system
5.1.1. Increased throughput
5.1.2. Economical
5.1.3. Increased reliability