UNIVERSITY EXAMINATIONS: 2014/2015
ORDINARY EXAMINATION FOR THE BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY
BIT 1106A OPERATING SYSTEM
DATE: DECEMBER, 2014 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO
QUESTION ONE
a) Explain the following terms as used in Computer Operating systems:
i). Clock Interrupt [2 Marks]
ii). Trap [2 Marks]
iii). Device driver [2 Marks]
iv). Critical race condition [3 Marks]
b) Describe the function of the kernel in memory management. [5 Marks]
c) Explain five factors to consider when selecting a file design method [5 Marks]
d) With the aid of diagrams describe the three and five process states. [6 Marks]
e) Discuss the functions of the high level scheduler. [5 Marks]
QUESTION TWO
a) Distinguish between deadlock and starvation. [4 Marks]
b) With the aid of a diagram, explain the concept of segmentation as used in memory
management scheme. [4 Marks]
c) Describe the objectives of I/O management. [5 Marks]
d) Discuss the following scheduling algorithms
i). FIFO [2 Marks]
ii). Shortest remaining time next [2 Marks]
iii).Shortest job first [2 Marks]
QUESTION THREE
a) Explain the following terms with respect to scheduling and performance maximization:
i). Throughput [2 Marks]
ii). Turnaround time [2 Marks]
iii).Response time [2 Marks]
b) Briefly explain five functions of PCB [5 Marks]
c) Give the benefits of Direct Memory Access (DMA) in I/O device management.
[4Marks]
d) Briefly explain five factors that may lead to a process switch. [5 Marks]
QUESTION FOUR
Explain the following with reference to file management;
i). file security [2
Marks]
ii). file integrity [2 Marks]
iii). File map [2 Marks]
a) Give the benefits of using directories in the file system [6 Marks]
b) Discuss in detail four file organization methods. [8 Marks]
QUESTION FIVE
Security goals of any computer system are decided by its security policies. Briefly
explain three computer security goals that can be set in an operating system.
[6
Marks]
a) State and explain four types of security threats to consider when designing and implementing any operating system. [8 Marks]
b) Describe the functions of process control block. [6 Marks]
