BCS1333 ASSIGNMENT 1

--updated 25/jan/11---------------------------------------------

Here are some of the materials for Assignment1

Chapter 1 : INTRODUCTION. Wiley - Operating Systems Concepts

Chapter 2 : OS STRUCTURES. Wiley - Operating Systems Concepts

Chapter 3 : PROCESSES . Wiley - Operating Systems Concepts

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1. In a multiprogramming and time-sharing environment, several users share the system simultaneously. This situation can result in carious security problems. [chapter 1]

1. What are two such problems?
   
2. Can we ensure the same degree in a time-shared machine as in a dedicated machine? Explain your answer.
   

2. Describe the differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantage of multiprocessor systems? [Chapter 1]

3. Distinguish between the client-server and peer-to-peer models of distributed systems. [chapter 1]

4. Direct memory access is used for high-speed I/O devices in order to avoid increasing the CPU's execution load. [chapter 1]

1. How does the CPU interface with the device to coordinate the transfer?
   
2. How does the CPU know when the memory operations are complete?
   

5. Give two reasons why caches are useful. What problems do they solve? What problems do they cause? [chapter 1]

6. What are the two models of interprocess communication? What are the strengths and weakness of the two approaches? [Chapter 2]

7. What is mechanism? What is policy? Why is the separation of both desirable? [Chapter 2]

8. What is the main advantage for an operating-system designer of using a virtual-machine architecture? What is the main advantage for the user? [Chapter 2]

9. Describe the differences among short-term and long-term scheduling. [Chapter 3]

10. Describe the actions taken by a kernel to context-switch between processes. [Chapter 3]

11. What are the benefits and disadvantages of each of the following? Consider both the system level and programmer level. [Chapter 3]

1. Synchronous and asynchronous communication
   
2. Send by copy and explicit buffering
   
3. Fixed-sized and variable-sized messages