I know there are many devices for accessing car computers or ECUS. Even though I want to make my own experience. So I will apreciate any guidance in preparing the code for this. Opening COM or LPT and and GETing the bits of info from a pin.
Thanks in advance
Javier

Though one... And unfortunately, depends on which OS you develop
You'll need an external component (DLL, OCX, VxD, etc) to be able to access hardware at low level. This holds especially for any NT-based OS, since the OS "protects" the hardware.
Once you have the external component, accessing your choice of port depends on the programming model of the component.