@Ymer il faut modifier le fichier /boot/config.txt comme suit :

#video mode hdmi_group=2 #1024x768 60Hz hdmi_mode=16 #1280x1024 60 #hdmi_mode=35

ensuite dans le recalbox.conf :

## Set game resolution for emulators ## select your mode from the command : tvservice -m [MODE] ## CEA 5 HDMI : 1920x1080 @ 60Hz 16:9, clock:74MHz interlaced ## CEA 4 HDMI : 1280x720 @ 60Hz 16:9, clock:74MHz progressive ## use 'default' for using the default resolution ## (string) ## video mode for 4/3 Monitor in 1024x768 global.videomode=DMT 16 HDMI

et voila