100201.asm

这个是8253芯片的两个实例程序

data segment
DATA ENDS
CODE SEGMENT
	Assume	cs:code,ds:data
start:mov dx,data
      mov ds,dx
      mov al,00100111b
      mov dx,283h
      out dx,al 
      mov al,10
      mov dx,280h
      out dx,al
      mov al,01010101b
      mov dx,283h;输入控制字
      out dx,al 
      mov al,5
      mov dx,281h
      out dx,al
      hlt
      mov   ah,4ch
      int   21h
      code	ends
end   start