It is very possible I'm making a beginner's mistake here, but is there a way to have GTA's 800x600x32 mode aspect-scale to full screen in DOSBox? I have DOSBox outputting at 1920x1200. I know in this particular example outputting at game-native and have the monitor do the scaling works just fine, but let's say I'd prefer the game's 640x480x32, which also does not upscale.

In general there seem to be certain games (or resolutions) that stubbornly refuse to be upscaled. Is there a logic behind what works and what does not? And a workaround? Mechwarrior 2, for instance, scales to full screen just fine at 800x600 or 1024x768, but several games, like GTA, or Windows 3.11 just 1:1 pixel-map to the output resolution.

I have tried output=overlay, opengl and openglnb and scaler=none and normal2x.

PS- In general I usually have scaler set to none, and generally everything still upscales to the output resolution just fine, which seems strange to me, but it could be I misunderstand the function of scalers (are they for instance perhaps only for non-trivial / enhanced scaling algorithms?).