fsaa

The option documentation is properly formatted yet

Description: "Full-scene anti-aliasing (FSAA)" Default: 0 Example: 4 Type: choice

Set to 2, 4 or 8 to enable full-scene anti-aliasing (reduces jagged edges in menu-mode). Specify 2 for 2x, 4 for 4x, etc. This may negatively impact rendering performance, depending on your GPU.

Value: 0 ("Off") Value: 2 (2x2) Value: 4 (4x4) Value: 8 (8x8)

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