MOV     SCON, #00H;    MODE 0 AS A TRANSMITTER
HERE:  MOV     A, P1;         MOVE THE DATA ON P1(DIP-SWITCH) TO ACCUMULATOR
       CLR     TI;            CLEAR THE BIT TI
       MOV     SBUF, A;       MOVE THE DATA TO SBUF
       JNB     TI,$ ;         PAUSE UNTIL THE TI BIT IS SET
       SJMP    HERE

MOV    SCON, #10H;    MODE O AS A RECEIVER
WAIT:   JNB    RI, WAIT;      PAUSE UNTIL THE RI BIT IS SET
        CLR    RI
        MOV    A, SBUF;       MOVE THE DATA SEND TO ACC
        MOV    P1, A;         MOVE ACC TO P1 (LED'S)
        SJMP   WAIT