UNIVERSITY EXAMINATIONS: 2018/2019
EXAMINATION FOR THE DIPLOMA IN BUSINESS INFORMATION
TECHNOLOGY
DBIT403 COMPUTER OPERATING SYSTEMS
FULLTIME/PARTTIME
DATE: NOVEMBER, 2018 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE [30 MARKS]
(a) Explain three measures that could be taken to ensure the safety of information stored in a
computer system [3 Marks]
(b) Differentiate between deadlock avoidance and deadlock prevention as used in operating
systems [4 Marks]
(c) KCA University is currently using single level directory structure to keep files in the
computer system and the institution is experiencing problems associated with this method.
Required:
(i) Outline two disadvantages of this structure [2 Marks]
(ii) With the aid of a suitable example, describe an alternative directory structure that
could improve the efficiency of their file management system [4 Marks]
(d) List and explain five key functions of a computer operating system [5 Marks]
(e) Outline three typical components of a Graphical User Interface (GUI) as used in operating
systems [3 Marks]
(f) Describe the functions of each of the following schedulers in operating system:-[3 Marks]
(i) Long term scheduler
(ii) Short term scheduler
(iii)Medium term scheduler
(g) Explain six factors you would consider while selecting a computer operating system [6
Marks]
QUESTION TWO [20 MARKS]
(a) List and explain four categories of operating systems [4 Marks]
(b) Briefly describe the following process scheduling algorithms used by operating systems:-
(i) FIFO [3 Marks]
(ii) Priority scheduling [3 Marks]
(iii)Shortest remaining job first [3 Marks]
(c) Explain four features of modern computer operating systems [4 Marks]
(d) Explain the following terms as used in operating systems:- [3 Marks]
(i) Monitors
(ii) Deadlock
(iii)Starvation
QUESTION THREE [20 MARKS]
(a) The following are software products available in the market.
Ubuntu, Karspersky, Linux, Novel Netware, MS DOS, Windows 7, text editor
Required: Classify the above software’s under either operating systems or utility programs
[7 Marks]
(b) Explain five objectives of process scheduling [5 Marks]
(c) Differentiate between the following terms as used in operating systems:- [8 Marks]
(i) Multiprocessing & multiprogramming
(ii) Response time & turnaround time
(iii)Open source software & closed source software
(iv)System software and application software
QUESTION FOUR [20 MARKS]
(a) Outline four functions of device independent I/O (Input/ Output) software. [4 Marks]
(b) List and explain four conditions necessary for a deadlock condition to occur in a computer
system [8 Marks]
(c) Explain each of the following terms as used in operating system:
(i) Context switch [2 Marks]
(ii) Pre-emptive scheduling [2 Marks]
(iii)Process scheduling [2 Marks]
(iv)Operating system [2 Marks]
QUESTION FIVE [20 MARKS]
(a) Explain three ways in which operating systems attempt to deal with deadlocks. [3 Marks]
(b) With aid of diagrams, describe the following OS memory management techniques:-
(i) Paging [3 Marks]
(ii) Segmentation [3 Marks]
(iii)Fixed multiple partition allocation method [3 Marks]
(c) Write DOS commands that would carry out the following:- [3 Marks]
(i) Display all directories in drive C:\
(ii) Display todays date
(iii)Create a directory named computers in drive D:\
(d) With the aid of a process state model, show the five states of a process [5 Marks]
