The code below doesn't work. I have to comunicate a PC with a 89S53. I'm using VB5 to send chars to 89S53. When the uC receive a char, it invert the P1.0. It must transmit the status os P1 all time, but it don't happen. The uC receive the char normally but don't transmit nothing.
Someone can help me ?

Thanks.

Nelson

$MOD51
$TITLE( PM4 )

ORG 0000H
SJMP INIT_UART

ORG 0023H
SERIAL:
JNB RI,EXIT
CPL P1.0
CLR P1.7
EXIT:
CLR RI
CLR TI
RETI



INIT_UART:

MOV SCON,#50H
MOV TMOD,#20H
MOV TH1,#0FAH
MOV TL1,#0FAH
ORL PCON,#80H

MOV IE,#90H
MOV IP,#10H
SETB TR1


ENVIA_CHAR:
MOV SBUF,P1
JNB TI,$
LJMP ENVIA_CHAR
END