I connected  both signals  together TXD (transmit) and RXD (receive) at
output computer serial port to test if serial port was chosen right and it
working properly. I would like make a very simple program to test the
computer  RS-232  serial port ,similar as HyperTerminal from Windows. If
port is OK, then transmit signals will go out and receive signals will go
in.
 I am taking beginning course of VB and did not learn so many.
I will appreciate for any commence.
Thanks, Leo