SCON1	 EQU 0C0H
		TI1	 BIT 0C1H
		SW1	 BIT P2.0
		ORG	 0H			
		MOV	 TMOD,#20H
		MOV	 TH1,#-3		
		MOV	 SCON,#50H
		MOV	 SCON1,#50H
		SETB	 TR1
	   	SETB	 SW1			
S1:		JB	 SW1,NEXT		
   		MOV	 DPTR,#MESS1	
FN:	   	CLR	 A
		MOVC	 A,@A+DPTR		
		JZ	 S1			
		ACALL	 SENDCOM1		
		INC	 DPTR			
		SJMP	 FN
NEXT:		MOV	 DPTR,#MESS2	
LN:		CLR	 A
		MOVC	 A,@A+DPTR		
		JZ	 S1			
		ACALL	 SENDCOM2		
		INC	 DPTR			
		SJMP	 LN
SENDCOM1:
		MOV	 SBUF,A		
HERE:		JNB	 TI,HERE		
     	CLR	 TI			
     	RET
SENDCOM2:
		MOV	 SBUF1,A		
HERE1:	JNB	 TI1,HERE1		
     	CLR	 TI1			
     	RET
MESS1:	DB	 "Hello",0
MESS2:	DB	 "Goodbye",0
		END