Test Papers / Previous Question Papers of IGNOU CS02 Introduction to Software December 1995

PGDCA / MCA (I Yr) / BCA
Term-End Examination

December, 1995

CS02 : Introduction to Software

Time: 2 hours
Maximum Marks: 60

1. (a) Design an algorithm that accepts an input a decimal number and converts it into BCD (binary coded decimal) representation.
(b) How can you develop a compiler of any language say C-language through the same language? Give the name of this process and also explain it.
(c) Write a grammar for an English language statement and draw a parse tree for the statement "The tall boy went to school".
(d) Write a regular expression for unsigned number in C-language.
(e) Explain the principles of abstraction.
(f) Consider the following set of processes which arrive in the ready queue the same time:

 Process CPU time
 P1 10
 P2 5
 P3 2
 P4 8
 P5 5

Consider the following scheduling algorithms :
FCFS, SJF and Round robin (quantum = 1)
What is turnaround time of each process for each of the above scheduling algorithms?
What is waiting time of each process for each of the above scheduling algorithms?

2. (a) What are the main advantages of distributed operating system? How are file system and protection supported in distributed operating system?
(b) Discuss the features of the following :
Network Operating System
Centralized Operating System
Distributed Operating System

3. In multiprogramming environment sharing of code and data can greatly reduce the real storage needed by a group of processes to run efficiently. For each of the following types of systems, outline briefly how sharing can be implemented :
(a) Partition
(b) Paging
(c) Segmentation

4. Explain the typical phases of SDLC (software development life cycle) and associated development tools.

5. (a) What is system call? Give 4 different examples of system calls in Unix operating system.
(b) In Unix system, the same system calls are used to read (or write) files, devices and interprocess message buffers. Describe its advantages briefly.
(c) Summarize the features of Unix systems that have made them such phenomenally successful operating systems.