ORG	 0
BACK:		MOV 	 A,#55H
		MOV 	 P0,A
		MOV 	 P1,A
		MOV	 P2,A
		ACALL	 QSDELAY		
		MOV 	 A,#0AAH
		MOV 	 P0,A
		MOV 	 P1,A
		MOV	 P2,A
		ACALL	 QSDELAY
		SJMP	 BACK
QSDELAY:
		MOV	 R5, #11
H3:		MOV	 R4, #248    
H2:  		MOV	 R3, #255    
H1:	 	DJNZ	 R3, H1 		
    		DJNZ	 R4, H2  
    		DJNZ	 R5, H3  
   		RET             
		END