i’m using 1080i display which is in 720p mode for emulationstation using /boot/config.txt (hdmi_mode=4, overscan_scale=1).
In 1080i, emulationstation menu is overscaned but in 720p it is fine.
I’m running gpsp at default setting “runcommand 4” and i have not overscan.
I have black borders in gpsp !
