View source for CSC231 Midterm Preparation

=A List of Problems to Prepare for the In-Class Closed-Books Midterm=

* Write a small assembly program (don't worry about writing a complete program: just the data and instructions necessary) that displays all the letters of the alphabet on the screen.
* Write a program that displays the first 20 fibonacci terms.
* Write a program that stores the factorial of word-variable x into word-variable y.
* What is the contents of eax, ebx, ecx, and edx after the execution of each instruction?

                        mov    eax,10
                        mov    edx,0
                        mov    bx,3
                        div    bx
                        
               

* What's a segmentation fault? Give an example of an instruction that would cause one.
* What is printed by this program?

                        section .data
                msg     db 10,10,10,"hello ",10
                msg2    db "world",10,"!"
                msg3    db 0x0a

                        section .text
                        mov     ebx,msg
                        add     byte [ebx+9],'-'-10
                        mov     byte [msg3-2],' '

                        mov     eax,WRITE
                        mov     ebx,STDOUT
                        lea     ecx,[msg]
                        mov     edx,msg3-msg
                        int     0x80
                  

* What's a big endian processor? a small endian processor?
* Write a program that uses only one string of characters "********" and that prints this pattern:

                  ********
                  ******
                  ****
                  **
                  

* Show the memory once the following data section of a program has been loaded into memory (indicate hex values with a 0x... prefix)

                              section .data
                  a           dd        10
                  b           dd        -1
                  msg         db        1,2,3,4,5,6,7
                  c           dw        0xaa

                  

* What is the binary and hexadecimal representations of the following 16-bit words (assume we are using 2's complement)?

                  65


                  -3


                  32767

                  
                  

* What is the advantage of 2's complement over other systems of representation of signed integers?
* What is the contents of the different registers after the following instructions have finished executing?

                             mov   eax,"231a"
                             and   eax,0xff00ff00
                             mov   ebx,0
                             mov   bl, '+'
                             shl   ebx,16
                             or    bl, '-'
                             or    eax,ebx
                  

* what is the purpose of the ADC instruction? When is it useful?