Fundamentals of Computer Organization FCO 1999

Gujarat University

MCA Semester I

FCO

Date: 8/1/1999                                                                                                                                    Marks:50

Section I

Q-1 a) Answer the following questions:                                                                                                         [4]

i)                    Convert the following decimal number 250.3 to binary, octal and hexadecimal numbers.

ii)                  Perform the following operation using 2’s complement and 1’s complement

(11.11)₂ – (10.111) ₂

iii)                Perform the following operation using 10’s complement and 9’s complement

(20)₁₀ – (1000)₁₀

iv)                Multiply and divide the following binary numbers in binary system

(11) ₂ – (0.101) ₂

        b) Find the minimal sum of product and product of sum expression for the following function using

Karnaugh maps and realize the expression using appropriate gates. Also realize sum of product form using NAND-to-NAND gate network and convert this gate network to AND-to-OR gate network. Use as few gates as possible.                                                                                                                                 [5]

F(W,X,Y,Z) = åm(0,13,4,6,12,13,14,15) + åd(2,5,7)

Here, m represents minterms and d represents Don’t care conditions.

Q-2 a) Explain the working of a modulo-8 Binary counter using suitable flip-flop.                                      [4]

OR

       a) Explain the working of Binary Half-Adder. Construct a Full-adder from half-Adders.                   

       b) Answer the following questions:                                                                                                         [4]

i)                    Prove De Morgan’s theorems for three variables

ii)                  Explain the floating point number representation in the computer system

iii)                Explain the different types of character recognition techniques.

Q-3 a) Explain with diagram a 3-to-8 DECODER.                                                                                       [3]

OR

a)      Explain with diagram an 8-input MULTIPLEXER.

b)      Explain the two-dimensional selection system in memory organization.                                          [5]

OR

b)      Design a 3-bit counter with the following binary sequence using RS flip-flops.                             

000, 001, 011, 010, 100, 101, 111 and repeat

Section II

Q-4 a) Explain the instruction and execution cycle organization of the control registers.                             [3]

        b) Answer the following questions:                                                                                                          [6]

i)                    Explain the different addressing techniques using suitable examples.

ii)                  Explain the logical operations performed by the ALU.

iii)                Write a note on Mouse.

Q-5 a) Explain the architecture or features of any 16-bit microprocessor.                                                     [4]

OR

       a) Answer the following questions:        

i)                    Explain the use of the flag register and the different addressing modes used in 8080 microprocessor.

ii)                  Explain the use of tri-state drivers in BUS system of the computer.

       b) Write short notes on the following: (any two)                                                                                                [4]

i)                    Error Detection and Error correction

ii)                  Register Transfer Language

iii)                Floppy disk controller

Q-6 a) Distinguish between the following (any four)                                                                                     [8]

i)                    Impact and non-Impact printers

ii)                  Combinational circuits and Sequential circuits

iii)                Floppy Disk Drive and Hard Disk Drive

iv)                Static RAM and Dynamic RAM

v)                  RS flip-flops and JK flip-flops

Fundamentals of Computer Organization FCO

Gujarat University

MCA Semester I

FCO

Date: 23^rd January, 1998                                                                                                                  Marks:50

Instructions:

1.      Answer to the two sections should be written in separate answer books.

2.      Assume suitable additional data if necessary.

3.      Figures to the right indicate full marks of the question.

Section I

Q-1 a) Answer the following:

            i)  Convert decimal number 189.3 to octal and hexadecimal numbers.                                              [4]

            ii) Perform following operation using 2’s complement and 1’s complement.           

                        (1101.1)₂ – (110.01)₂

            iii) Convert hexadecimal number BA5.C to octal and decimal numbers.

            iv) Perform following operation using 9’s complement.

                        (1859)₁₀ – (732) ₁₀ and (686) ₁₀ – (2164) ₁₀

     b) Find the minimal sum of product and product of sum expression for the following using k’ map and realize

using appropriate gates. Also realize sum of product form using NAND-NAND circuit.                 [5]

f(A,B,C,D) = åm (0,1,2,7,8,10,13,15) + åd(9,14)

Here m represents minterms and p represents don’t care conditions.

Q-2 a) Design a full adder using appropriate gates. How can you convert this design using NAND gates only?

                                                                                                                                                                        [4]

       b) Answer the following:                                                                                                                         [4]

i)                    Multiply and divide following binary numbers in binary system.

10101 and 110

ii)                  Prove following using Boolean algebra

(A + B). (A’ + B’ + c) + A.B = A + B

iii)                Convert (11010)₂ into gray code.

OR

Q-2 a) Explain the design of 3 bit shift register with parallel load facility. Use suitable flipflops.               [4]

       b) Answer the following:                                                                                                                         [4]

i)                    How can you find product of sum expression from K-map.

ii)                  Prove the following using Boolean algebra

A’C + A’B + AB’C + BC = C + A’B

            iii)        Give the usefulness of Parity Bit.

Q-3 a) Explain with diagram the working of 4 – input Multiplexer.                                                              [3]

       b) Explain 3 – bit Binary Up/Down Counter using JK-FlipFlops.                                                          [4]

       c) How Demultiplexer differs from decoder?                                                                                         [1]

OR

Q-3 a) Explain with diagram the 3 to 8 decoder with enable input.                                                              [3]

      b) Design a 3-bit counter using sequential logic with following counting sequence using JK- Flipflop. [5]

            000, 010, 011, 111, 100 and repeat

Section II

Q-4 a) Answer the following (any four)                                                                                                         [6]

i)                    How Keyboard is connected to motherboard? How it is sending data to the CPU?

ii)                  Explain the use of MAR, MBR and Instruction counter in Control Unit of a Computer.

iii)                Explain how floating point number are represented in Computer? How they are added?

iv)                Give the usefulness of tri-state buffers in BUS system of Computer.

v)                  Write short note on Light Pen.

        b) Write short note on JK- Master Slave FlipFlop.                                                                                 [3]

Q-5 a) Explain with diagram the working of CRT display controller. Give also difference between text mode and

graphics mode.                                                                                                                                    [3]

       b) Answer the following:

            i) Give the features of DMA technique. Where it is used in PC?                                                      [5]

                  ii) What is the difference between IMPACT and NON-IMPACT type of printer? Explain the principle of     

     NON-IMPACT printers.

OR

Q-5 a) Give the characteristics of Printer and explain working of Dot Matrix printer.                                  [3]

        b) Explain the difference between FDD and HDD. What is formatting of disk? How data is stored in disk?

                                                                                                                                                                        [3]

       c) Explain the use of Flag register and Segment registers in 8086.                                                         [2]

Q-6 a) Explain the architecture OR features of any 8-bit microprocessor.                                                     [4]

       b) Write short notes on following:                                                                                                           [4]

i)                    Register Transfer Language

ii)                  Use of Interrupts in PC

OR

Q-6 a) What is addressing technique? Explain in brief.                                                                                 [3]

       b) Write short notes on following:

i)                    EISA Bus

ii)                  68000 Microprocessor