Hi,
i have tried all the available resolutions
but there is no difference.
I think whatever i select, nothing changes.
When i make a choice
at the bottom of the screen a line appears with the message:
/opt/retropie/lib/inifuncs.sh: line 60
/op/retropie/configs/all/videomodes.cfg: Permission denied
When the emulator is set to lr-imame4all
i can change the resolution successfully.