@nyvram said in N64 question...something overwriting my changes to mupen64plus.cfg. What is it?:
/configs/n64/emulators.cfg included hard-coded resolutions (1920x1080) for widesceen monitors and this was what kept overwriting the [video-general] section in the mupen64plus.cfg file.
That's strange, there shouldn't be any hardcoded values there with a default RetroPie install - unless the user has manually modified the launch scripts. How did you install RetroPie ?