JUNE 2009 CS-64: INTRODUCTION TO COMPUTER ORGANISATION QUESTION PAPER

IGNOU BCA CS-64: INTRODUCTION TO COMPUTER ORGANIZATION - JUNE 2009 QUESTION PAPER

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BACHELOR IN COMPUTER APPLICATIONS

Term-End Examination

June, 2009

 CS-64: INTRODUCTION TO COMPUTER ORGANISATION

Time : 3 Hours

Max. Marks : 75

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Note : Question one is compulsory. Answer any three questions from the rest.

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1. (a) Using 2's complement notation perform the following arithmetic operations using 8-bit register.
(i) 25 + (-12)
(ii) 13 - 8
(iii) -19-17
(iv) -8 + 18
(v) 12 - (-9)
Also write overflow/underflow if any.
(b) Write a program for evaluating A*B/C+D/E-F using 2 address and 3 address machine instructions . Make assumptions, if required.
(c) How can a stack be used for implementing a subroutine call? Can this scheme be used to pass parameter also ? Justify your answer. [4 marks]
(d) Write program in 8086 assembly language to count the numbers of vowels in a given string. Assume that 20 byte long string is stored in data segment.[5 Marks]
(e) Draw an arithmetic pipeline for floating point subtraction.[5 Marks]
(f) What is RAID? What are RAID levels? Explain any two levels giving data distribution and advantages/disadvanteges of that level.[5marks]

2. (a) What is the need of having many addressing modes in a machine? Explain any four most important addressing modes for your machine and justify your selection. [5 Marks]
(b) Design a combinational circuit that generates an odd parity for four digit number input.[5 Marks]
(c) Give block diagram of DMA controller.How does CPU initialize the DMA transfer?[5 Marks]

3. (a) Write a program in 8086 assembly language to display a string stored in the data segment on the computer monitor,only if the first character of the string is an upper case alphabet.[5 Marks]
(b) Compare the various advantages and disadvantages of isolated mapped I/O scheme and memory mapped I/O scheme.[5 Marks]
(c) "Counter is a register". Justify your answer. Draw and explain the working priciples of a 4-bit asynchronus ripple counter.[5 Marks]

4. (a) Show that {NAND} is a functionally complete set of gates.Use it to construct the OR,AND and NOT gates.[5 Marks]
(b) Draw the circuit for 4-bit ROM having four words and explain the design.
(c) What is an interrupt? How is the interrupt 21 h used in 8086 microprocessor?

5. (a) Design a floating Point Number format for the following requirements:
Base:2
Mantissa: Normalized, should hold 4 significant decimal digits.
Exponent: Biased exponent in the range of +25 single precision.
Make suitable assumptions,if any.
(b) What is Wilkes control? Is it different from hardwired control? Justify. Also explain how a microprogram can be executed?
(c) Explain the use of 'AAA' and 'DAA' instructions with the help of an example of each, for 8086 micro-processor:
(a) Mask and insertion operation.
(b) Linker and Loader.
(c) Associative Memory.
(d) Co-processor and Peripheral processor.
(e) Multiplexer and Decoder.

6. Describe the following terms in context of computer organisation of 8086 micro-processor:
(a) Mask and insertion operation.
(b) Linker and Loader.
(c) Associative Memory.
(d) Co-processor and Peripheral processor.
(e) Multiplexer and Decoder.