Emulator RetroArch

Systems: nearly everything HaulNX downloads for · Runs as: homebrew NRO · Get it: retroarch.com → Nintendo Switch, or the libretro install guide

Best effort: this guide is community-maintained and may lag behind new releases. The emulator's own site (linked above) is the authoritative source — if anything here doesn't match what you see, trust their instructions.

RetroArch is the one-install-covers-everything option: a frontend with per-system "cores" for almost every console in HaulNX's folder list. If you only set up one emulator, make it this one.

Install

1. Download the Switch build from retroarch.com (a .7z archive).
2. Extract the archive to the root of your SD card, merging/overwriting. You end up with:
   • sd:/retroarch/ — config, assets, cores
   • sd:/switch/retroarch_switch.nro — the app itself
3. Cores live in sd:/retroarch/cores/ as .nro files. The full package ships with all of them; you can also add or update cores in-app via Main Menu › Online Updater.

Point it at your HaulNX library

RetroArch builds playlists by scanning folders — and it's happy to scan HaulNX's whole tree in one go:

1. Download some games with HaulNX (they land in sd:/roms/<console>/).
2. In RetroArch: Import Content › Scan Directory, navigate to sd:/roms, and pick <Scan This Directory>.
3. One playlist per recognized system appears on the home screen. Rescan whenever you've downloaded more.

Two things to know about the scanner:

• It matches against the libretro database (checksums / known filenames). Well-known dumps import cleanly; oddballs may be skipped. For those, use Import Content › Manual Scan, point it at the specific sd:/roms/<console> folder, and pick the system + default core yourself. Manual Scan is also the right tool for arcade / fbneo sets.
• Zips are fine for most cartridge-era systems — cores read ROMs straight out of the archive. CD-era content (psx, sega-cd, saturn, dc) generally wants extracted .cue/.bin or .chd files.

You can also skip playlists entirely: Load Content and browse to sd:/roms/... directly.

BIOS files

Some cores need console BIOS files before they'll run anything. On Switch the system directory defaults to sd:/retroarch/cores/system/ (check yours under Settings › Directory › System/BIOS). Files go directly in that folder — no subfolders unless a core's docs say so.

The usual suspects: psx (scph5501.bin and friends), sega-cd (bios_CD_U.bin etc.), saturn, pc-engine-cd (syscard3.pce), neo-geo (neogeo.zip), 3do, nds, fds (disksys.rom). Cartridge systems (NES/SNES/Genesis/GB/GBA...) need nothing.

Suggested cores per HaulNX folder

Availability varies a little between RetroArch releases; this is the well-trodden path on Switch:

HaulNX folder	Core	Notes
nes, fds	Mesen or FCEUmm	FCEUmm is lighter
snes	Snes9x
n64	Mupen64Plus-Next	Overclock helps; not every game is clean
gb, gbc	Gambatte or SameBoy
gba	mGBA	The standalone mGBA is also excellent
nds	melonDS DS	Standalone melonDS often faster
virtual-boy	Beetle VB
pokemon-mini	PokeMini
game-and-watch	GW
sg-1000, master-system, game-gear	Genesis Plus GX
genesis, sega-cd	Genesis Plus GX	Sega CD needs BIOS
sega-32x	PicoDrive
saturn	Beetle Saturn / Yaba Sanshiro	Heavy — expect misses on Switch
dc, naomi, atomiswave	Flycast	Surprisingly good; overclock recommended
psx	PCSX-ReARMed	Needs BIOS; has a dynarec, runs great
psp	PPSSPP core	Standalone PPSSPP is the better experience
pc-engine, supergrafx	Beetle PCE Fast / Beetle SuperGrafx
pc-engine-cd	Beetle PCE Fast	Needs syscard3.pce
pc-fx	Beetle PC-FX
neo-geo, fbneo, arcade	FBNeo (or MAME 2003-Plus for arcade)	Needs neogeo.zip BIOS; romset version matters
neo-geo-pocket, neo-geo-pocket-color	Beetle NeoPop
wonderswan, wonderswan-color	Beetle Cygne
atari-2600	Stella
atari-5200	Atari800 or a5200
atari-7800	ProSystem
atari-lynx	Handy / Beetle Lynx
atari-jaguar	Virtual Jaguar	Slow — temper expectations
colecovision	blueMSX or Gearcoleco
intellivision	FreeIntv
odyssey2	O2EM
vectrex	vecx
channel-f	FreeChaF
supervision	Potator
3do	Opera	Needs BIOS
cd-i	—	No practical Switch option
gc, wii, ps2, 3ds	—	Beyond the Switch — folders are for library organization only

Tips

• Rescan after every HaulNX session — playlists don't watch the filesystem.
• If a scan finds nothing, check you scanned sd:/roms and not a subfolder of the wrong drive letter mount — on Switch the SD root is just / in RetroArch's file browser, so the path reads /roms.
• Changed HaulNX's ROM Download Folder (Settings › Manage data)? Scan that folder instead.