: USB drives used for transfers must be formatted to FAT32 or exFAT to be recognized by both your PC and the Raspberry Pi.
| System | Best Format | Tool | Why | |--------|-------------|------|-----| | PS1 | .chd or .pbp | chdman (MAME) or PSX2PSP | Saves 30–50% space, single file | | N64 | .z64 | – | No compression needed | | Arcade | .zip (unchanged) | – | MAME/FBNeo requires original zip | | Sega CD / PCE-CD | .chd | chdman | Massive space savings | | All cartridge-based | .zip (optional) | – | Works with lr-* cores | retropie roms pack top