MAME ROM sets come in two primary formats: merged and non-merged.
Common files (e.g., sound CPU ROMs, graphics tiles) are duplicated across clones — meaning storage size approximates (sum of all unique roms) + (sum of all shared roms × clone_count) . non merged mame rom set
Are you looking to like MAMEdev or a front-end like LaunchBox with your ROMs? What is a Non-Merged MAME ROM Set
In a non-merged set, each game has its own unique ROM files, without any duplication or overlap with other games. This approach has several advantages: set up a specific emulator Are you looking
In the world of arcade emulation, games often share common code. A "parent" game (like the original Japanese Puckman ) contains the core data, while "clones" (like the US Pac-Man ) only contain the unique differences.