Hi @acris
i created a file snes9x.cfg inside /recalbox/share_init/system/configs/pisnes/ like this:
[Graphics]
MaintainAspectRatio=1
[Joystick]
A_1=0
B_1=1
L_1=4
R_1=5
SELECT_1=6
START_1=7
X_1=2
Y_1=3
[Path]
RomFolder=/recalbox/share/roms/snes
SaveStateFolder=/recalbox/share/saves/snes
but it's still not working, snes emulator stays full screen 16/9
Instead, i looked for what was forcing MaintainAspectRatio to 0 inside /recalbox/share/system/configs/pisnes/snes9x.cfg
and i found this script /usr/lib/python2.7/site-packages/configgen/generators/pisnes/pisnesGenerator.py containing:
# Full screen settings
key = "integerscale"
intScale = key in system.config and system.config[key] in ('1', 'true')
config.setOption(self.SECTION_GFX, "MaintainAspectRatio", '1' if intScale else '0')
i changed the last line to this: config.setOption(self.SECTION_GFX, "MaintainAspectRatio", '1')
so it forces MaintainAspectRatio=1 in the /recalbox/share/system/configs/pisnes/snes9x.cfg config file
it works perfectly, snes emulator is now at 4/3 format
i hope this will help