ROM File Formats¶
Every system folder under Roms/ accepts the formats its emulator reads
natively — the tables below list them per system. On top of that, the
built-in cores all accept zipped ROMs, and most users only need one
rule of thumb: uncompressed is best, CD games should be CHD, and
arcade zips must stay exactly as they are.
Compressed ROMs (.zip and .7z)¶
Any game launched through a built-in core can be a .zip or .7z
archive:
- Cores that read archives themselves (FBNeo, the Commodore cores, Amiga) get the file untouched.
- For every other core, NX Redux extracts the ROM out of the archive at launch and hands the core the extracted file. The copy is kept in RAM until the device powers off, so only the first launch of a session pays the extraction delay.
This does not apply to the standalone emulators —
Nintendo 64, Nintendo DS and
Sega Dreamcast get their files directly, so give them
uncompressed images (Dreamcast's .chd is compressed internally and is
the recommended format there anyway).
Uncompressed vs .zip vs .7z¶
Prefer uncompressed ROMs (.gb, .sfc, .md, …). The only thing
compression buys is SD card space, and cartridge ROMs are tiny next to
any modern card. Uncompressed files win everything else:
- Fastest launch — the core reads the file directly, with no extraction step, every time.
- No RAM overhead — extracted copies of compressed ROMs live in RAM until the device powers off, and the Trimui devices only have 1 GB shared with the emulator itself. An uncompressed ROM costs nothing.
- Works everywhere — including the standalone emulators, which do not get the automatic extraction.
| Format | Pros | Cons |
|---|---|---|
Uncompressed (.gb, .sfc, …) |
Fastest launch, no RAM overhead, works everywhere | Largest files on the SD card |
.zip |
Smaller files, standard romset convention | Extraction delay on first launch; extracted copy sits in RAM all session |
.7z |
Smallest files | Slowest extraction of the three; same RAM cost as .zip |
Compressed cartridge ROMs still work fine if that is the form your
library is already in — for typical carts (up to a few dozen MB) the
extraction delay is under a second and the RAM cost is small. Just
don't bother compressing yourself, and if you keep archives, prefer
.zip over .7z: the extra space .7z saves is small and its
extraction is noticeably slower on these devices.
Never zip CD images
Do not compress CD-based games (PlayStation, Sega CD,
TurboGrafx-CD) into .zip/.7z. A .cue + .bin pair stops
working when archived (only one file gets extracted), and a large
image can exhaust the device's RAM during extraction. Use .chd
instead — it is heavily compressed and read directly, with no
extraction step and no RAM cost.
Arcade zips are not compressed ROMs
Roms/Arcade (FBN)/ zips are romsets — the zip itself is the
game's identity and FBNeo reads it directly. Never extract or
re-compress them, and see the Arcade page for naming
rules.
Formats per system¶
Native formats verified against each bundled core. Remember .zip and
.7z work for all of these on top of what is listed; multi-disc games
use .m3u playlists.
Cartridge & handheld systems¶
| System | Core | Formats |
|---|---|---|
| Atari 2600 (A2600) | stella2014 | a26 bin |
| Atari 5200 (A5200) | a5200 | a52 bin |
| Atari 7800 (A7800) | prosystem | a78 bin cdf |
| Atari Lynx (LYNX) | handy | lnx lyx o |
| Colecovision (COLECO) | gearcoleco | col cv bin rom |
| Famicom Disk System (FDS) | fceumm | fds |
| Game Boy (GB) / Game Boy Color (GBC) | gambatte | gb gbc dmg |
| Game Boy Advance (GBA) | gpsp | gba bin agb gbz |
| Game Boy Advance (MGBA) | mgba | gba |
| Super Game Boy (SGB) | mgba | gb gbc sgb |
| Neo Geo Pocket (NGP/NGPC) | race | ngp ngc ngpc npc |
| Nintendo ES (FC) | fceumm | nes unf unif |
| Pico-8 (P8) | fake-08 | p8 png |
| Pokémon mini (PKM) | pokemini | min |
| Sega Genesis (MD) | picodrive | md gen smd bin 68k sgd |
| Sega 32X (32X) | picodrive | 32x bin |
| Sega Game Gear (GG) | picodrive | gg |
| Sega Master System (SMS) | picodrive | sms |
| Sega SG-1000 (SG1000) | picodrive | sg sc |
| Super Nintendo ES (SFC) | snes9x | sfc smc swc fig bs st |
| Super Nintendo ES (SUPA) | mednafen_supafaust | sfc smc swc fig |
| TurboGrafx-16 (PCE) | mednafen_pce_fast | pce + CD: cue ccd chd toc m3u |
| Virtual Boy (VB) | mednafen_vb | vb vboy bin |
CD-based systems¶
| System | Core | Formats |
|---|---|---|
| Sony PlayStation (PS) | pcsx_rearmed | chd cue bin img iso pbp toc mdf cbn m3u exe |
| Sega CD (SEGACD) | picodrive | chd cue bin iso m3u |
.chd is the recommended format for both — single file per disc,
compressed, no extraction.
Computers & other¶
| System | Core | Formats |
|---|---|---|
| Amiga (PUAE) | puae2021 | adf adz dms fdi ipf hdf hdz lha slave info cue ccd iso chd uae m3u (zip/7z native) |
| Amstrad CPC (CPC) | cap32 | dsk sna tap cdt voc cpr m3u (zip native) |
| Commodore 64 (C64) / 128 (C128) / PET / Plus4 / VIC-20 | VICE | d64 d71 d81 g64 x64 t64 tap prg p00 crt bin m3u vsf and more (zip/7z/gz native) |
| Microsoft MSX (MSX) | bluemsx | rom ri mx1 mx2 dsk cas m3u |
| Doom (PRBOOM) | prboom | wad iwad pwad lmp |
| Arcade (FBN) | fbneo | zip 7z romsets — see Arcade |
Standalone emulators¶
| System | Emulator | Formats |
|---|---|---|
| Nintendo 64 (N64) | mupen64plus | z64 n64 v64 |
| Nintendo DS (NDS) | DraStic | nds |
| DreamCast (DC) | Flycast | chd gdi cdi cue + Naomi/Atomiswave zip — see Dreamcast |
Additional emulators installed from the Xtras store or as community paks follow their own emulator's formats.