Hi floob, it’s your vids I have been watching and following which I have found incredibly helpful.
It’s really hard to explain the issue but the x or m on emulator start (although changing the resolution) doesn’t help with the issue. Can you see in the castlevania image I attached how instead of the top left saying “player and enemy” it says “layer and nemy” it’s because the left side of the screen is cut off. It’s not cut off the TV as there are the normal black borders of a 4:3 screen on a 16:9.
If I use retroarch menu to change top left and bottom right it simply stretches what is already there, it doesn’t show any more of the picture.