Reg. No:…………………………….
KIGALI INSTITUTE OF SCIENCE AND TECHNOLOGY
INSTITUT DES SCIENCES ET TECHNOLOGIE
Avenue de l'Armée, B.P. 3900 Kigali, Rwanda
INSTITUTE EXAMINATIONS–ACADEMIC YEAR 2012-2013
END OF TRIMESTER EXAMINATION: TRIMESTER II
FACULTY OF ENGINEERING
COMPUTER ENGINEERING AND INFORMATION TECHNOLOGY
SECOND YEAR – COMPUTER SCIENCE (MUSANZE AND PT AT KIST)
CIT 3212 OPERATING SYSTEMS
DATE:
/
/2013
TIME: 2 HOURS
MAXIMUM MARKS = 60
INSTRUCTIONS
1. This paper contains Section A and Section B
2. Answer Question 1 in Section A and any TWO (2) questions in
Section B.
3. No written materials allowed
4. Write all your answers in the answer booklet provided.
5. Do not forget to write your Registration Number.
6. Do not write any answers on this question paper.
SECTION A
Question 1 (30 marks)
a)
What are the functions of an operating system? List only
four functions. (4 marks)
b)
Briefly discuss only five types of operating systems. (10
marks)
c)
Briefly discuss bootstrap process with the help of a
diagram. (6 marks)
d)
What is encryption? (1 mark)
e)
Discuss the two security schemes used i.e. Data Encryption
Standard (DES) and Public Key Encryption (PKE) with the
help of diagrams. (5 marks)
f)
Discuss the four categories of the effects of dangers facing
a computer system. (4 marks)
SECTION B
Question 2 (15 marks)
a)
What are the five principal problems to be handled by the
Operating System’s memory manager? (10 marks)
b)
Discuss the two disadvantages found in fixed partition memory.
(6 marks)
c)
Distinguish between coalescing and compaction of holes. (4
marks)
Question 3 (15 marks)
a)
What is a deadlock? (1 mark)
b)
Discuss the four conditions for a deadlock. (4 marks)
c)
One way of dealing with deadlock is deadlock avoidance
which is based on safe and unsafe state. Distinguish
between safe and an unsafe state. (5 marks)
d)
Discuss how to prevent deadlocks. (5 marks)
Question 4 (15 marks)
a)
Discuss the two principal objectives of I/O System. (5
marks)
b)
Discuss the Five Process State Model with the help of a
diagram. (10 marks)
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