3_2_1.asm

华工电信系汇编习题的编程实现

stack segment stack 'stack'
      dw 32 dup(?)
stack ends

data segment 

     B1 db 01H
     B2 db 23H
     B3 db 21H
     B4 db 14H
     B5 db ?
data ends

code segment 
begin proc far
      assume ss:stack,cs:code,ds:data
      push ds
      sub ax,ax
      push ax
      mov ax,data
      mov ds,ax

      mov al,B1   ;ax 1471
      add al,B2   ;ax 1401
      daa         ;ax 1424
      sub al,B3   ;ax 1424
      daa         ;ax 1403
      add al,B4   ;ax 1417
      daa         ;ax 1417
      mov B5,al   ;ax 1417 
 
      ret
                           ;result right
begin   endp
code    ends
      end begin