UNIVERSITY EXAMINATIONS: 2017/2018
EXAMINATION FOR THE DEGREE OF MASTER OF SCIENCE IN DATA
COMMUNICATION
MDC 6104 OPERATING SYSTEMS THEORY AND DESIGN
DATE: AUGUST 2018 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE [20 MARKS]
a) Define the term operating systems indicating the main function. [3 Marks]
b) Differentiate DMA and Shell as used in operating systems [2 Marks]
c) Nakshi intends to install an operating system in her personal computer. Explain two factors
that she should consider before purchasing the operating system. [4 Marks]
d) Explain the following memory placement techniques.
(i) Best fit [2 Marks]
(ii) First fit [2 Marks]
e) (i) What does the term firmware mean as used in operating systems? [2 Marks]
(ii) Describe the term device independence as used in operating systems. [2 Marks]
f) Joshua has been learning MS-DOS commands. He was excited to have mastered a few
commands. Please explain the following the function of each of these commands to him.
(i) Rd command [1 Mark]
(ii) Md command [1 Mark]
(iii) Dir command [1 Mark]
QUESTION TWO [15 MARKS]
a) Explain the term cache as used in memory management. [2 Marks]
b) Explain the main differences between registers, main memory and cache. [2 Marks]
c) Which of the above is the fastest? [1 Mark]
d) Why is RAM referred to as the main memory? [1 Mark]
e) Mercy is aware that there are two types of interface. Command based and graphical user
interface. However, she prefers to use command based interface. Explain three reasons for
her preferences. [3 Marks]
f) Differentiate between threads and processes. [2 Marks]
g) Explain each of the following terms as used in operating systems:
i) port [2 Marks]
ii) message [2 Marks]
QUESTION THREE [15 MARKS]
a) Using a well labeled diagram explain the steps and activities involved in process execution.
[4 Marks]
b) Outline three reasons that could cause a process to terminate. [3 Marks]
c) Kaparo is designing an operating system. Explain three qualities of a process scheduling
algorithm that he should put into consideration. [4 Marks]
d) Explain the circumstance under which the First Come First Served process schedule
algorithm could be applied. [2 Marks]
e) Joy was investigating conditions necessary for deadlocks in operating systems. Outline two
conditions that she was likely to identify. [2 Marks]
QUESTION FOUR [15 MARKS]
a) With the aid of diagrams, describe two types of fixed partition allocation used in memory
management. [9 Marks]
b) Kaparo was required to investigate disadvantages of virtual machines in computers. Explain
three disadvantages that he could have established. [3 Marks]
c) Explain three advantages of First Come First Served (FCFS) scheduling algorithms.
[3 Marks]
