Cork Institute of Technology
Bachelor of Science (Honours) in Computer Applications – Stage 3
(Bachelor of Science in Computer Applications – Stage 3)
(NFQ – Level 8)
Autumn 2005
Computer Systems III
(Time: 3 Hours)
Answer question ONE and THREE other questions.
All questions carry equal marks.
Hardware reference guide book is available.
Examiners: Dr. J. Creagh
Dr. D. Chambers
Mr. E. A. Parslow
Mr. P. O’Connor
Q1. (a) Write an 80386 subroutine, which may be called from a C/C++ program to examine a
string.
The first and second words in the string must be returned. Diagram of stack required.
Example: FindFirstTwoWords (Str,Res1,Res2)
The first parameter ‘Str’ represents the string of characters to be examined.
The second parameter ‘Res1’ represents the buffer area for storing the first word found.
The third parameter ‘Res2’ represents the buffer area for storing the second word found.
Sample Data Input Str = ‘1960, The 3 fields.’
Output Res1 = ‘The’
Res2 = ‘fields’
Note 1: ASCII ‘0’ = 30H ‘A’ = 41H ‘a’ = 61H
Note 2 : A word is considered to consist of one or more continuous letter characters.
(16 marks)
(b) Write a detailed report describing stack manipulation required for C/C++ access to 80386
subroutines. Reference to part (a) above is required. (7 marks)
(c) Explain why C/C++ access to 80386 assembly language subroutines may be
useful / necessary. (2 marks)
