Note : Question 1 is compulsory. Attempt any three from the rest.

1. (a) Design an algorithm that converts binary number to octal.

(b) What is usefulness of context free grammar?

(c) Construct context free grammar for C-language conditional and looping statements.

(d) Compare and contrast dynamic loading and dynamic linking loader schemes.

(e) Write regular expressions for
· A set of strings including {d, abd, cd, abed}
· A set of strings of x’s, y’s and z’s

For ex {xxx, xxy, xxz, ...zzz}

(f) Discuss the similarities and differences between paging and segmentation.

(g) Given several reasons why the study of concurrency is appropriate in operating system design.

(h) Explain the drawbacks of waterfall model.

2. (a) How is a client-server model different from the kernel approach and virtual approach?

(b) List various advantages of client-server model.

(c) What is motivation of multiprogramming?

3. Explain the principles of the following :
(a) Prototyping
(b) Reusability
(c) Abstraction
(d) Separate compilation

4. (a) What are important tasks performed during
· Lexical analysis
· Syntax analysis
· Semantic analysis
· Code generation

(b) Explain the principles of
· LEX
· YACC

5. (a) Explain the concepts of
· Synchronization
· Interprocess Communication
· Mutual Exclusion

(b) Write a mutual exclusion algorithm for two processes. Explain its drawback.

6. (a) Describe the directory structure of Unix file system.

(b) All I/O in a Unix system is stream-oriented rather than record-oriented as it is in most other systems. Discuss the advantages and disadvantages of the approach.

(c) Summarize the features of Unix systems that have made them such phenomenally successful operating systems.