200751310584472310.txt

一个由汇编实现的两个数相加

DATA SEGMENT
     X DB ?
     Y DB ?
     S DB ?,?
     mess1 db "Input x=(0 quit)","$"
     mess3 db 'Input y=','$'
     mess2 db 'x+y=$'
DATA ENDS
stack segment  para stack 'stack'
      dw 100 dup(?)
stack ends
CODE SEGMENT
     ASSUME CS:CODE,DS:DATA,ss:stack
START: MOV AX,DATA
       MOV DS,AX
l1:   lea dx,mess1
       mov ah,9
       int 21h
       MOV AH,1
       INT 21H
       cmp al,'0'
       jl   exit         
       cmp al,'9'
       ja   exit         
       cmp al,'0'         
       je l2             
       MOV X,AL
       call cr_lf
       lea dx,mess3
l4:     mov ah,9
       int 21h  
       MOV AH,1
       INT 21H
       cmp al,'0'
       jl   l3
       cmp al,'9'
       ja   l3         
       MOV Y,AL
       MOV AL,X
       AND AL,0FH
       MOV BL,Y
       AND BL,0FH
       ADD AL,BL
       cbw
       mov bl,10
       div bl
       or al,30h
       mov s,al
       or ah,30h
       mov [s+1],ah
       call cr_lf
       mov dx,offset mess2
       mov ah,9
       int 21h
       MOV AH,2
       MOV DL,s
       INT 21H
       mov ah,2
       mov dl,[s+1]
       int 21h
       call cr_lf
       jmp l1
exit :  mov ah,61h
        int 21h     
        mov dl,0ah
        mov ah,2
        int 21h
        mov dl,0dh
        mov ah,2
       int 21h   
         jmp l1     
l3:    mov ah,61h
        int 21h
        mov dl,0ah
        mov ah,2
        int 21h
        mov dl,0dh
        mov ah,2
       int 21h 
        jmp l4          
l2:    MOV AH,4CH
       INT 21H
   
cr_lf  proc
       push ax
       push dx
       mov ah,2
       mov dl,0ah
       int 21h
       mov ah,2
       mov dl,0dh
       int 21h
       pop dx
       pop ax
       ret
cr_lf  endp
CODE   ENDS
       END START