david,
You said Windows does not allow the same low level access to I/O ports and memory that i have in DOS, thats mean i cann't use the i/o port which is already in used by windows?
The i/o interface card i have ,is using i/o address form 2E0h~2F1H and i
checked already that there is not conflict to the windows i/o port address.
i also simply create a inline assembler code on Visual C++, which can read or write to the particular i/o address port. When i run the .exe file the windows didn't appear any error message, it just appear a dos windows on the screen, and prompt the message" press any key to continue" when i press any key the dos windows is close.So i think didn't have any conflict to the windows assigned i/o port address.
i try to create an dll project and add a c++ source file the type my inline assembler code, i had not problem to compile the .cpp and build the .dll file but after that i want to run the executable file, i can not find the .exe file to run. Can you tell me how to run the dll file which i had create?

thank.