data segmentmess1       db 'Please input the  mark!',0ah,0dh,'$'mess2       db 'The average mark is:',0ah,0dh,'$'buf1         db 60db ?db 60 dup(?)buf2         db 30  dup(?)buf3         db 2 dup(0),'$'data endscode segmentassume cs:code,ds:datastart:  mov ax,datamov ds,axlea dx,mess1mov ah,9int 21hcall input	  lea      si,buf1	  mov      cx,[si+1]	  and      cx,0fh	  shr       cx,1	  dec       cx	  lea       di, buf2	  mov       al,[di]	  L2:     inc        di	  add       ax,[di]	  loop       L2	  div        cl	  call        output	  ;=====================================================================================	  input  proc                               ;該子程序把輸入的成績轉換成一字節壓縮BCD碼存放	  pushf	  push  ax	  push  cx	  push  bx	  push  dx	      push  di	      mov     dx,offset buf1	      mov     ah,0ah	      int     21h	  lea      si,buf1	  mov      dl,0	  mov      bl,0	  mov      cx,[si+1]	  and      cx,0fh	  shr       cx,1	  lea       di,buf2	  L1:     mov      dl,[si+2]               ;把輸入的第一個數字給dl	  sub      dl,30h	  shl      dl,1	  shl      dl,1	  shl      dl,1	  shl      dl,1	  mov      bl,[si+3]               ;把輸入的第二個數字給bl	  sub       bl,30h	  add       dl,bl	  mov       [di],dl	  inc       di	  add       si,2	  loop       L1	  pop        di	  pop        dx	  pop        bx	  pop     cx	  pop     ax	  popf	  ret	  input endp	  ;===============================================================================	  output proc                                         ;該子程序把BCD碼轉換成asc碼	  push      bx	  push      cx	  push      dx          push      si	  push      di	  mov       cl,4	  lea       si,buf3	  mov       ah,al          mov       bl,ah	  shr        bl,cl	  add       bl,30h	  mov       [si],bl	  and       ah,0fh	  add       ah,30h	  mov       [si+1],ah	  lea dx,mess2	  mov ah,9	  int 21h	  mov  dx,offset buf3	  mov  ah,9	  int   21h	  pop       di	  pop       si	  pop       dx	  pop       cx	  pop       bx	  ret	  output endp	  code ends	  end start