NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
OCTOBER/NOVEMBER 2014 EXAMINATION

COURSE CODE:                                                                              CIT 344                                                                               

COURSE TITLE:                                                                             Introduction to Computer Design

DURATION:                                                                                     3 Hours

INSTRUCTIONS:                                                                            Answer any Five Questions

Q1a.     What is the full meaning of the following acronyms?

(i)        BCD                 (ii)       ASCII               (iii)      ALU                 (iv)      CPU

(v)       SBRAM           (vi)      GHz                 (vii)     EPROM           (viii)    m p

(ix)      K – map                                                                                                    (1 mark each)     

     b.    Convert the following:

(i)        25.37510 to Binary

(ii)       101.1012 to decimal

(iii)      Convert BCD number 0110100000111001 to its decimal equivalent.

(iv)      Gray Code 1100 to Binary

(v)       23710 to Binary.                                                                                     (1 mark each)

Q2.a     Write short notes with examples on the following:

(i)        BCD Code       (ii)       Gray Code      (iii)      ASCII Code                     (2 marks each)

      b.   Generate the Truth Table of NAND gate based S-R latch                                                    (8 marks each)

Q3.a     Why learn Assembly Language?                                                                                          (4 marks)

      b.   Write four (4) differences between assembly language and high level language          (4 marks)

      c.    List three (3) assembly language statements.                                                                    (6 marks)

Q4.a     Explain the term “Microprocessor”                                                                                     (5 marks)

      b.   List three (3) internal components of a microprocessor                                                              (3 marks)

       c.   Mention and explain three (3) types of computer languages you know.                        (6 marks)

Q5a.     Discuss briefly on the following:

(i)        Flip flops        (ii) Multiplexers                                                             (2 marks each)

      b.   Identify three (3) differences between Multiplexers and De multiplexers                     (6 marks)

      c.    Encode the following decimal numbers in BCD code:

(i)        47        (ii)       23                                                                                    (2 marks each)

Q6a.     Explain the term “Decoder”                                                                                                              (5 marks)

     b.    Identify 3 differences between Decoders and Encoders                                                              (6 marks)

      c.    List three Flip-Flop Operating Characteristics you know                                                              (3 marks)      

Q7a.     Convert the following to Octal and then to hexadecimal:

(i)        101100110011                     (ii)       10011000010110                     (4 marks each)

(b) Convert the following numbers from octal to decimal:

(i)           7438                     (ii)         124.258                                                                                   (3 marks each)