I have a 800x480 5 inch display for my Raspberry Pi 3 project, and DosBox stretches to fill the width by default.
Currently I'm using Batocera as the "game browser OS" but happy to switch to the more traditional RetroPi if it helps. (It's just that Batocera starts up faster)
In Batocera, the dosbox config file is located in \share\system\configs\dosbox\dosbox.conf, and I can change it to a fixed resolution there, where it draws from the top left corner if I go smaller than the native resoultion, but changing "aspect" to "true" doesn't have any effect.
What's curious is the only "output" options in this version of Dosbox is (as listed in the conf file)
# Possible values: surface, texture, texturenb.
and I've never seen these options before so it must be specific to the Raspberry Pi version of Dosbox. Maybe they don't support aspect ratio correction.
I saw that there are some low level settings in the Raspberry pi config.txt where you can force a border / scaling on the HDMI output, but I couldn't get them to have an effect. With the default image of Batocera there is a config.txt at the top level folder, but I read it should be under boot\config.txt, so I copied it there - no luck either. I couldn't get any change. The settings I was using to get 4:3 on my 800x600 display;
Code: Select all
disable_overscan=0 overscan_left=100 overscan_right=100