ORG    0000H
						LJMP   MAIN
						ORG    0100H
MAIN:              
	                   BUSY EQU  P2.0
 		                 REQ  EQU  P2.1
				        CLR  REQ
						SETB BUSY     
                        MOV    A,#0F0H
						ACALL  SUB1
						MOV    A,#02H
						ACALL  SUB1
						MOV    A,#00H
						ACALL  SUB1
						MOV    A,#10H
						ACALL  SUB1
						MOV    A,#01H
						ACALL   SUB1
						SJMP $
SUB1:                   JB     BUSY,SUB1
                        MOV    P1,A
						NOP
						SETB   REQ
HE3:                    JNB    BUSY,HE3
                        CLR    REQ
						RET

						END