There are three main methods of transferring ROMs: via USB stick, via SFTP, and via Windows (Samba) shares. That being said, in the search of your childhood - Google is your friend. There are many issues involving copyright laws regarding the usage of ROMs, so in order to preserve the integrity and longevity of the RetroPie project, the download locations of ROMs will not and cannot be added to the Wiki. In a RetroPie context, ROMs are digital copies of games which can be run on emulators (software that mimics your old gaming consoles).
Universal Controller Calibration & Mapping Using xboxdrvĬonvert RetroPie SD Card Image to NOOBS Image
Validating, Rebuilding, and Filtering Arcade ROMs