sound.asm

用8253编制秒表延迟程序

data segment
      a1    db 'hello!',0dh,0ah,'$'
data ends	
code segment
 assume  cs:code,ds:data
 start:mov  ax,data
       mov  ds,ax
       mov  dx,offset a1
       mov  ah,09h
       int  21h 
       mov  cx,10
       mov di,988
       mov  bx,1000
 sing: call sound
       loop sing
       mov  ah,4ch
       int  21h
;---------sound-------
sound  proc near
       push ax
       push bx
       push cx
       push di
       mov  al,0b6h
       out  43h,al
       mov  dx,0020h
       mov  ax,34deh
       div  di
       out  42h,al
       mov  al,ah
       out  42h,al
       in   al,61h       ;read PB
       mov  ah,al
       or   al,3
       out  61h,al
  wait1:  mov  cx,07fffh
  delay:loop delay
          dec  bx
          jnz  wait1
          mov  al,ah
          out  61h,al
	  pop  di
          pop  cx
	  pop  bx
          pop  ax	  
       ret
  sound  endp                   
code   ends
       end start