;假设在数据段X_SEG,附加段Y_SEG和堆栈段Z_SEG中分别定义了
;字变量X,Y和Z,编制程序计算:X<--X+Y+Z.
x_seg segment
org 1000h
x dw 1
x_seg ends
y_seg segment
y dw 2
y_seg ends
z_seg segment
z dw 3
z_seg ends
code segment
assume ds:x_seg,es:y_seg,ss:z_seg,cs:code
start:mov ax,x_seg
      mov ds,ax
      mov ax,y_seg
      mov es,ax
      mov ax,z_seg
      mov ss,ax
      mov ax,ds:[x]
      add ax,es:[y]
      add ax,ss:[z]
      mov x,ax
      mov dx,x
      add dx,30h
      mov ah,2
      int 21h
      mov ah,4ch
      int 21h 
code ends
     end start