CLR SM0			
SETB SM1			
       
SETB REN			
       
MOV A, PCON			
SETB ACC.7			
MOV PCON, A			
       
MOV TMOD, #20H		
MOV TH1, #-3		
MOV TL1, #-3		
SETB TR1			
MOV R1, #30H		
      again:
JNB RI, $			
CLR RI			
MOV A, SBUF			
CJNE A, #0DH, skip	
JMP finish			
      skip:
MOV @R1, A			
INC R1			
JMP again			
      finish:
JMP $