I run most DOSbox games like this:

[sdl]
fullscreen=false
windowresolution=1100x825
output=overlay
autolock=true

[render]
frameskip=0
aspect=true
scaler=normal2x

because it's windowed and it maintains 4:3 aspect ratio.

I want to run Flashback the same way, but the game's aspect ratio is weird (the default resolution is 256 x 224) and the config only increases the resolution to 512 x 448 (double). I tried changing the output and the resolution to 944 x 826. Didn't work.

What can I do to run it in a _____ x 825 window?