CS401 Assignment # 3 Best Solution - Spring 2013

Open the com in AFD:
On command prompt type afd filename.com

The following AFD commands will be helpful for you.

CMD> M1 DS : 100
the above mentioned command will display the contents of memory location at offset address "0x0100" in memory window 1 (the address of the location where normally your first variable is stored, if your first variable is a word then moving two bytes ahead will display the contents of next vraiable e.g. M1 DS:102)
Similarly to display data contents in memory window 2 use the following command
CMD> M2 DS : 100

For help press F4 at CMD, the help window will be appeared at the bottom now either press PageUP/PageDown keys to move back and forth or type any command at command prompt, the command that you will type, its help will appear in the help window.

Use F2 to execute the program statement by statement. E.g. press F2 to execute first statement and then see the effect of this statement in registers, or memory window (by using command M1 or M2 described above)
If you want to change the values of the registers directly in the debugger then here is the command:
register=value
For example, you want to set 1DD0 in DS register, you will write like this:
ds=1DD0
and press Enter.
Or there is also another way, you can move between these different windows (register window, memory window etc) by pressing F8 or F9 keys in the debugger and then typing the value in the respective window.
Finally use quit command to exit from the shell.
On DOS command prompt type cls and press Enter to clear the screen

org 0x100]

jmp start
ARRAY: dw 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10
SUM: dw 0
SUM_OF_SQUARE:

mainloop: mov ax, [ARRAY + bx]
mul ax
add cx, ax
add bx, 2
cmp bx, 22
jnz mainloop
mov [SUM], cx
ret



start: mov ax, 0
mov bx, 0
mov cx, 0
mov dx, 0

call SUM_OF_SQUARE
mov dx, [SUM]
mov ax, 0x4c00
int 0x21