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Ilmars



Joined: 29 Nov 2005
Posts: 3
Ilmars
I'm beginner in FASM. And I have some strange problem.
Here is a code:

Code:
org 100h

       mov al,36h
       mov bl,35h

       mov ah,9h
       mov dx,text1
       int 21h
       mov ah,2h
       mov dl,al  ;?? 36h
       int 21h
       mov ah,9h

       cmp al,bl

       jbe first_below_or_equal
       mov dx,above
       jmp continue

first_below_or_equal:
       je  both_are_equal
       jmp first_is_below

first_is_below:
       mov dx,below
       jmp continue

both_are_equal:
       mov dx,equal

continue:
       int 21h
       mov ah,2h
       mov dl,bl
       int 21h
       mov ah,9h
       mov dx,text
       int 21h
       int 20h

text1  db "first number $"
bigger db " > $"
equal  db " = $"
below  db " < $"
text2  db " second number $"                     
    


I don't understand why it isn't working well.
If I change al with 36h (near 2 question marks) , then it's working nice.

Thank you already now. (:


Last edited by Ilmars on 29 Nov 2005, 14:13; edited 1 time in total
Post 29 Nov 2005, 13:33
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
Post 29 Nov 2005, 13:55
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Ilmars



Joined: 29 Nov 2005
Posts: 3
Ilmars
To vid:
I don't need a string output, i need symbol's, whose ASCII code is stored in al, output.

In first case (mov dl,al) output is
first number $ < 5 second number.
But it must be, (as in case of mov dl,36h)
first number 6 > 5 second number.

It's that I don't understand.
Post 29 Nov 2005, 14:09
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
If you would read link i sent you precisely, you will find out: int 21h/9: Return: AL = 24h (the '$' terminating the string, despite official docs which state that nothing is returned)
Code:
mov ah,9h 
mov dx,text1 
int 21h  ;this returns with al='$'
    
Post 29 Nov 2005, 14:29
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Madis731



Joined: 25 Sep 2003
Posts: 2141
Location: Estonia
Madis731
What he's telling you is that your al gets deleted from returning from int 21h so you are declaring al too soon. Here's code for example:
Code:
org 100h

;      mov al,36h ;This is too soon - it gets lost
       mov bl,35h

       mov ah,9h
       mov dx,text1
       int 21h
;      mov ah,2h
       mov ax,0236h ;You can define both (ah,al) here
       mov dl,al  ;al is 36h here and so will dl
       int 21h
       mov ah,9h

       cmp al,bl

       jbe first_below_or_equal
       mov dx,above
       jmp continue

first_below_or_equal:
       je  both_are_equal
       jmp first_is_below

first_is_below:
       mov dx,below
       jmp continue

both_are_equal:
       mov dx,equal

continue:
       int 21h
       mov ah,2h
       mov dl,bl
       int 21h
       mov ah,9h
       mov dx,text
       int 21h
       int 20h

text1  db "first number $"
bigger db " > $"
equal  db " = $"
below  db " < $"
text2  db " second number $"
    

Try that Wink
Post 29 Nov 2005, 14:55
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Ilmars



Joined: 29 Nov 2005
Posts: 3
Ilmars
Very big thank for you both (Madis731 and vid) !! Smile

Now it's OK.
Post 30 Nov 2005, 09:41
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