fullscreen_mode

The option documentation is properly formatted yet

Summary: "Fullscreen mode" Default: desktop Example: fullscreen Type: Choice

You can set this option to window instead if you want to use the fake fullscreen support (a borderless window the size of the current display will be created instead of switching to real fullscreen).

Value: fullscreen ("Fullscreen") - Classic fullscreen mode (SDL_FULLSCREEN) Value: desktop ("Fullscreen desktop") - New fullscreen mode (SDL_FULLSCREEN_DESKTOP) Value: window ("Fullscreen window") - Frameless window with same size as desktop

Source: https://github.com/FrodeSolheim/fs-uae/blob/master/docs/options/fullscreen_mode