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Reference BIOS Files

digdat0 edited this page Jul 24, 2026 · 2 revisions

Some systems need a copy of the original console's BIOS (or firmware) before an emulator will run anything. HaulNX ships no BIOS files — they're console firmware, not games — so you supply your own from hardware you own. This page is the one place that lists what's needed and where each emulator wants it, so the individual emulator pages don't have to repeat it.

Legal note: BIOS dumps are copyrighted. These pages assume you're dumping from your own console.

Which systems need one

Cartridge-era systems (NES, SNES, Genesis, Game Boy line, N64, GBA...) generally need nothing. BIOS matters mostly for CD-based systems, a few handhelds, and arcade:

HaulNX folder Needed? Typical file(s)
psx Required scph5501.bin / scph1001.bin / scph5500.bin (by region)
ps2 Required a PS2 BIOS dump for your region (e.g. scph39001.bin)
saturn Recommended saturn_bios.bin (sega_101.bin / mpr-17933.bin)
dc Recommended dc_boot.bin, dc_flash.bin
naomi Required naomi.zip (keep zipped)
atomiswave Required awbios.zip (keep zipped)
sega-cd Required bios_CD_U.bin / bios_CD_E.bin / bios_CD_J.bin
pc-engine-cd Required syscard3.pce
pc-fx Required pcfx.rom
neo-geo, neo-geo-cd Required neogeo.zip (keep zipped)
nds Required bios7.bin, bios9.bin, firmware.binDraStic wants the same dumps under different names
wiiu Required keys.txt (Wii U title keys, not a BIOS)
fds Required disksys.rom
3do Required panafz1.bin (or similar 3DO BIOS)
x68000-style / others Varies Check the core's docs

Cartridge systems not listed here need no BIOS.

Where each emulator looks

The same file goes to a different place depending on which app runs the system:

Emulator BIOS location
RetroArch (all cores) sd:/retroarch/cores/system/ — files directly in it, no subfolders unless a core's docs say otherwise
Flycast (dc/naomi/atomiswave) sd:/flycast/data/
melonDS (nds) next to the app, in sd:/switch/melonds/
DraStic (nds) sd:/switch/drastic/system/, renamed nds_bios_arm7.bin / nds_bios_arm9.bin / nds_firmware.bin
Cemu (wiiu) sd:/switch/Cemu/keys.txt
DuckStation (psx) its bios/ folder (set under Settings › BIOS)
NetherSX2 (ps2) sd:/switch/nethersx2/bios/
Yaba Sanshiro (saturn) its bios/ folder
MAME / pFBN (arcade/neo-geo) BIOS zips live in the romset folder with the games

Tips

  • Exact filenames matter. Emulators look for specific names (and often specific checksums). scph5501.bin renamed to psx.bin won't be found. If a game refuses to boot on a CD system, a wrong-named or wrong-region BIOS is the first thing to check.
  • Keep arcade BIOS zips zipped. neogeo.zip, naomi.zip, and awbios.zip are treated like romsets — don't extract them.
  • Region has to match the game for some systems (PS1, Saturn, Sega CD). If a game hangs on a black screen, try the BIOS for its region.

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