What language are you looking for? If you are looking for C or C++ code, then I can help alot. If it's VB, then you will have to use the MSComm control. I can't really help if it's VB.
Designer/Programmer of the Comtech Operating System(CTOS)
I have only heard things on Win NT based OS'es and I don't like it one bit(sorry ). I have never ever used an NT based system, I've only used Win 9x based. The problem with NT is that it restricts direct hardware access. You can only do direct hardware access if you do it with a driver.
For parallel port(printer port), try this C code. There's no guaranty that it'll work(you'll get a "priviledged exception" error). This is NOT my code, it's from the net.
Designer/Programmer of the Comtech Operating System(CTOS)