BZQ	EQU	20H	
	ORG	0
	LJMP	START
	ORG	0BH
	LJMP	TS
	ORG	30H
START:	MOV	SP,60H
	MOV	TMOD,#02H
	MOV	TH0,#0CEH
	MOV	TL0,#0CEH
	SETB	PT0
	SETB	ET0
	MOV	BZQ,#1
	MOV	R0,#1
	SETB	TR0
	SETB	EA
LOOP:	MOV	P1,#0FFH
	MOV	A,P1
	INC	A
	MOV	BZQ,A
	SJMP	LOOP
TS:	DJNZ	R0,FINISH
	CPL	P3.0
	MOV	R0,BZQ
FINISH:	RETI
	END