ORG	 0H      		
MAIN:	SETB	 P2.7   		
 	MOV	 A, #66H  		
   	MOV	 P1, A    		
TURN:
 	JNB	 P2.7, CW 		
  	RR	 A        		
  	ACALL	 DELAY   		
  	MOV	 P1,A      	
 	SJMP	 TURN     		
CW:	RL	 A          	
 	ACALL	 DELAY  		
  	MOV	 P1,A    		
  	SJMP	 TURN    		
DELAY:
  	MOV	 R2, #100
H1: 	MOV	 R3, #255
H2: 	DJNZ	 R3, H2
  	DJNZ	 R2,H1
   	RET
	END