UNIVERSITY EXAMINATIONS: 2011/2012
FIRST YEAR EXAMINATION FOR THE BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY
BIT 13021306 OPERATING SYSTEM
DATE: JULY, 2012 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO
QUESTION ONE
a) Explain the following terms:
i. Clock Interrupt [2 Marks]
ii. Trap [2 Marks]
iii. Device driver [2 Marks]
iv. Critical race condition [3 Marks]
b) Describe five functions of the kernel in process management. [5 Marks]
c) Briefly explain five factors to consider when selecting a file design method
[5 Marks]
d) Identify five principles of I/O software [5 Marks]
e) Discuss six functions of virtual memory. [6 Marks]
QUESTION TWO
a) Briefly describe each of the following terms as used in paging.
i. Page fault [2 Marks]
ii. Virtual address space [2 Marks]
iii. Physical address space [2 Marks]
b) With the aid of a diagram, explain the concept of segmentation as used in memory
management scheme. [3 Marks]
c) Describe the objectives of I/O management. [5 Marks]
d) Discuss the following scheduling algorithms
i. Multi-level queue [2 Marks]
ii. Event driven [2 Marks]
iii. FCFS [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) With the aid of a diagram discuss the five process state in operating systems.
[5 Marks]
c) Give the benefits of Direct Memory Access (DMA) in I/O device management.
[4 Marks]
d) Briefly explain five factors that may lead to a process switch. [5 Marks]
QUESTION FOUR
a) Explain the following with reference to file management;
i. file security [2 Marks]
ii. file integrity [2 Marks]
iii. File map [2 Marks]
b) Give the benefits of using directories in the file system [6 Marks]
c) Discuss in detail four file organization methods. [8 Marks]
QUESTION FIVE
a) 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]
b) State four types of security threats to consider when designing and implementing
any operating system. [4 Marks]
c) Discuss the objectives of I/O management. [8 Marks]
d) Describe device controller. [2 Marks]
