.ini or .cfg files that store user settings, button mappings, and video preferences.
The "8sk" suffix often appears in community-modified versions of emulators, sometimes associated with specific "skins," "sketches," or developer handles. Since I cannot open the file directly, here is the general context of what a "Nester" zip file typically contains: Nester8sk_Old.zip
A file like Nester.exe used to run NES games on a PC. sometimes associated with specific "skins
readme.txt or changes.txt files explaining the specific "Old" version's features or bug fixes. Nester8sk_Old.zip
Are you trying to with this version of Nester, or