CSS Computer Science 2011

Q.2. (a) Explain that: (02+02+01=05)

(i) In how many ways DMA process may be initiated and be terminated?

(ii) The sequence of events as DMA is requested by an I/O devices.

(iii) What happens when DMAC receives DMA request from another channel while it is serving one?

(b) Why Interrupts are employed in computer? Briefly describe basic types of Interrupts. (05)

(c) Differentiate between pre-emptive and non-pre-emptive scheduling. Briefly describe round robin and shortest scheduling policies with examples for each. (10)

A bunch of jobs is arriving in the Ready Queue as shown below using SRT and RR(Q=5). Calculate the average turnaround time. Draw the Gantt chart and describe which policy provides better results?

JOB A.T E.R. T

1 0 10

2 1 06

3 2 12

4 3 11

5 4 5

Q.3. (a) Consider a slotted ring of length 10 km with a data rate of 10 Mbps and 500 repeaters, each of which introduces a 1-bit delay. Each slot contains room for one source-address byte, one destination-address byte, two data bytes and five control bits for a total length of 37 bits. How many slots are on the ring? (09)

(b) Compare the capacity allocation schemes for IEEE 802.5 token ring and FDDI. What are the relative pros and cons? (05)

(c) Compare the individual fields of the IPv4 header with the IPv6 header. Account for the functionality provided by each IPv4 field by showing how the same functionality is provided in IPv6. (06)

Q.4. (a) What is polymorphism? How can we achieve polymorphism in Java and what are its prerequisites? (08)

(b) Write exception hierarchy in Java. Enlist the methods of Arithmetic exception, I/O Exception, Array Index Out of Bounds Exception Classes. (12)

Q.5. (a) Describe the use of Print Stack Trace Method. Consider STACK with memory size 8. Initially it is empty. Find out the output of the following algorithm: (09)

step 1. Set X :=4 and y :=6

step 2. Call PUSH(STACK, X+Y)

step 3. Call PUSH(STACK, 5)

step 4. Call PUSH(STACK, X+4)

step 5. Call PUSH(STACK, Y-3)

step 6. Call PUSH(STACK, Y-X)

step 7. Repeat while TOP !=NULL

Call POP(STACK, ITEM)

Write: ITEM

[loop ends]

step 8. Exit

(b) Elucidate the concept of Hashing. Explain in brief the various methods used to avoid collision in Hashing. (04)

(c) Insert Key Records: 76, 93, 40, 47, 10, 55 (in this sequence) into the Hash Table of length m = 7 with the Hash Function H(K) = K mod m. Perform linear and quadratic probing. (07)

Q.6. Write Short notes on the following: (5 x 4 = 20)

(a) Block Structure of PL/SQL

(b) Database Security

(c) Cybertalk: A new way to communicate

(d) The promise of virtual reality

Q.7. (a) What is normalization process? Explain the steps to normalize a relation with suitable examples. (09)

(b) Explain the DIFFERENCE between Client-Side Technologies and the Server-Side Technologies with some examples. (06)

(c) Define the following briefly: (1 x 5 = 5)

(i) Script

(ii) Servlet

(iii) CGI

(iv) UDDI

(v) SOAP