Thanks for the reply. Does the orientation affect the UI as well; if I flip from l>r to r>l will the UI change its orientation as well? Essentially I need to get MAME to send that data to some external hardware and perform an action depending on the video output orientation. I know it's doable but h...

Hi Guys, Does MAME have flags to indicate which way round the output video is displayed? This isn't too bad for landscape games, but with portrait games I need to have a value to tell me if it's L>R or R>L. Failing that, is there a way for all portrait games to be displayed in one direction only, or...