p172.asm

assume cs:code,ds:data,ss:stack

data segment
  db    128 dup(0)
data ends

stack segment stack
  db    128 dup(0)
stack ends

code segment

start:
  mov ax, stack
  mov ss, ax
  mov sp, 128

  mov ax, data
  mov ds, ax
  mov si, 0
  
  mov dx, 0
  mov ax, 1243
  call dtoc

  jmp quit

dtoc:
  ; 将 word 型数据转变为 十进制字符串 ax word型数据，ds:si 结果字符串首地址
  push ax
  push bx
  push cx
  push dx
  push si
  mov bx, 0
  div_proc:
    mov cx, 10
    div cx
    inc bx
    add dx, 30H
    push dx
    mov dx, 0
    mov cx, ax
    jcxz div_end
    jmp div_proc

  div_end:
    ; 除完后，将结果从栈中取出
    mov cx, bx
    get_result:
      pop bx
      mov ds:[si], bl
      inc si
      loop get_result
    ; 最后写一个 0
    mov byte ptr ds:[si], 0
    pop si
    pop dx
    pop cx
    pop bx
    pop ax
    ret

quit:
  mov ax, 4C00H
  int 21H
code ends

end start