li8.asm

一个用汇编程序编写出来的计算是否闰年的小程序

data segment
 mess1 db 'Input year:$'
 mess2 db 'is a leap year!$'
data ends
code segment
main proc far
 assume cs:code,ds:data
start:
 push ds
 sub ax,ax
 push ax
 mov ax,data
 mov ds,ax
 mov ah,9
 lea dx,mess1
 int 21h
 call decibin
 call crlf
;------------------
 mov ax,bx
 mov dx,0
 mov cx,4
 div cx
 cmp dx,0
 jne exit
 mov ax,bx
 mov dx,0
 mov cx,100
 div cx
 cmp dx,0
 jne disp
 mov cx,4
 div cx
 cmp dx,0
 jne exit
disp:
 mov ah,9
 lea dx,mess2
 int 21h
exit:
 ret
main endp
;------------------
decibin proc near
  mov bx,0
newchar:
  mov ah,1
  int 21h
  sub al,30h
  cmp al,0
  jb  exit1
  cmp al,9
  jnbe exit1
  cbw
  xchg ax,bx
  mov cx,10d
  mul cx
  xchg ax,bx
  add  bx,ax
  jmp  newchar
exit1:
  ret
decibin endp
;---------------
crlf proc near
  mov dl,0dh
  mov ah,2
  int 21h
  mov dl,0ah
  int 21h
  ret
crlf endp
;---------------
code ends
  end start