p285.asm

本程序是汇编语言的一些基本功能的组合

CODE SEGMENT
MAIN PROC FAR 
  ASSUME CS:CODE
START:
 CALL SOUND
 MOV AH,4CH
 INT 21H
MAIN ENDP
;------------------
SOUND PROC NEAR
  PUSH AX
  PUSH DX
  MOV  BX,0FFH
  MOV DX,CX
  IN AL,61H
  AND AL,11111100B
TRIG:
  XOR AL,2
  OUT 61H,AL
  MOV CX,BX
DELAY:
  MOV SI,0FFFFH
DELAY1:  
  DEC SI
  JNZ DELAY1
  LOOP DELAY
  DEC DX
  JNE TRIG
  POP DX
  POP AX
  RET
SOUND ENDP
;------------------
CODE ENDS
 END START