@aowoo said in How to access IO port in QT?:

directly read and write to the I/O port

AFAIK, It's impossible for Windows && Linux:

On Windows you need in a special driver (It is not enough to use just some DLL's, because you need in a driver. Most likelly, that inpout32.dll has a pre-compiled driver in own resources and loads this driver in runtime).

On Linux you need in a special permissions too.