Hi there
How do I write a simple value like 1(5v) to the DB9 port and how do I monitor the DB9 port for state changes on it?
Here is the scenario :
I made a circuit with a 16f627 processor that is connected to the PC via DB9 port.
The 16f circuit will listen and respond to activities on this port(wire number not relevant)
All I need to do now is code that will make one of the port wires active and the I will be able to figure out how to check for a certain stage(high or low) on the DB9 via the Java program.

Java is platform independent and therefore does not directly access hardware. One option is to use the SerialIO API. The other would be to use JNI to access the port using native code with another language such as C or C++.