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RetroBIOS

Nuance

Nuance emulates VM Labs Nuon. It reads 9 files, 3 of them required: without a required file it does not start games.

About this profile
Detail Value
Type libretro
Classification Official port
Source https://github.com/WizzardSK/nuance-libretro
Upstream https://github.com/andkrau/NuanceResurrection
Version 0.6.7, stated in src/libretro.cpp
Revision WizzardSK/nuance-libretro@daf3ca642756, andkrau/NuanceResurrection@daf3ca642756
Profiled 2026-09-03
Profile YAML, JSON
Cores nuance
Systems VM Labs Nuon
Install this emulator's files

The installer finds your setup and its BIOS folder, then downloads only the files this emulator reads there and checks each one.

Open the Start menu. Type PowerShell and open it. Paste the line. Press Enter.

PowerShell
&([scriptblock]::Create((irm https://abdess.github.io/retrobios/i.ps1))) --emulator nuance
Technical notes

NUON emulator written by Mike Perry (2002-2007) and continued as NuanceResurrection by Carsten Waechter from the source archive released after the author's death. The Linux and libretro ports were merged into the upstream tree in 2026 (pull request 75), and the port's last commit is part of the upstream history.

The three BIOS files are not firmware dumps. bios.cof, minibios.cof and minibiosX.cof are Aries assembly implementations of BIOS routines, assembled from bios.s, minibios.s and minibiosX.s in the source tree. Every other BIOS call is handled in C++ through BiosJumpTable (src/bios.cpp:395-547). The entries left to the assembly code are the comm bus calls, TimeToSleep, MPEWait and BiosGetInfo.

retro_load_game looks for <system>/nuance/bios.cof and changes the working directory to <system>/nuance when it exists, else to the directory of the core library when bios.cof sits beside it (src/libretro.cpp:332-371). Every data file is then opened by bare name from the working directory. InitBios loads bios.cof into MPE3 and MediaInitMPE loads minibios.cof into MPE0 (minibiosX.cof on MPEs 1 to 3). A failed load prints "Missing File!" and emulation continues without the routines. LoadCoffFile checks the COFF magic 0x0120 and copies the sections to their physical addresses. No size or hash is checked (src/coff.cpp:47-176).

Two builds of bios.cof exist. The source tree carries the NuanceExperimental build (23938 bytes, 12 sections, with commrecv_vars and commrecv_queues). The 0.6.6 and 0.6.7 release archives ship the 2007 build (19410 bytes, 10 sections). Both carry the same biosvars, haltab, biosinfo, halstub, biosdata, halts and controllerdata sections and the C++ side references neither extra section.

nuance.cfg is read from the working directory, then from the directory of the running executable (src/NuonEnvironment.cpp:547-563). Without it the values set in NuonEnvironment::Init apply. The GLSL shaders are opened from the working directory and fall back to the copies compiled into the binary (src/ShaderProgram.cpp:94-144, src/embedded_shaders.h). FlashEEPROM.bin is read by the FlashEEPROM constructor and written by the destructor, both relative to the process working directory at load and unload of the core (src/FlashEEPROM.h:36-51). Game data (nuon.run, nuon.dat) is read from the loaded disc image or directory, and no other fixed file is opened.

Files

Section titled “Files”

9 files: 3 required, 6 optional.

In this collection: 8 in repo and 1 missing.

Required

Section titled “Required”
FileStatusHash

bios.cof

BIOS routines for MPE3, Aries COFF assembled from bios.s

  • Path: nuance/bios.cof
  • Loaded into MPE3 by InitBios through LoadCoffFile, which rejects a file whose magic is not 0x0120 (src/coff.cpp:47-71). The 2007 build shipped in the release archives (19410 bytes, sha1 4f42ed8f5e171cc79112d1c1e201381e83b1fc0d) loads the same way.
Hashes and source
in repoMD5 23bf80c259f1

minibios.cof

Media MPE minibios for MPE0, assembled from minibios.s

  • Path: nuance/minibios.cof
  • Loaded by MediaInitMPE when the media MPE is MPE0, which InitBios does at every BIOS initialisation. Entry point and interrupt vectors come from the fixed addresses in Bios.h.
Hashes and source
  • SHA1: 5265dbc871ada59dbd384104c578d807438af4c7
  • MD5: 1abc7f6265b82742154be881cff2cd3f
  • Asked for by: emulator code, libretro port
  • Source: src/media.cpp:243-321 (emulator code, libretro port), src/bios.cpp:661 (emulator code, libretro port), src/Bios.h:29-33 (emulator code, libretro port)
in repoMD5 1abc7f6265b8

minibiosX.cof

Media MPE minibios for MPEs 1 to 3, addresses shifted down by 4 KB

  • Path: nuance/minibiosX.cof
  • Loaded by MediaInitMPE when a program installs the minibios on an MPE other than MPE0.
Hashes and source
  • SHA1: e45a96ce18486573c4d30efbc01658ce1ff8cd55
  • MD5: ceb37f4e78c1f396b49bb6372c83fd7c
  • Asked for by: emulator code, libretro port
  • Source: src/media.cpp:277-296 (emulator code, libretro port), src/Bios.h:35-38 (emulator code, libretro port)
in repoMD5 ceb37f4e78c1

Optional

Section titled “Optional”
FileStatusHash

nuance.cfg

Emulator configuration (compiler options, audio interrupts, controller mappings)

  • Path: nuance/nuance.cfg
  • Read from the working directory, then beside the running executable. Absent file leaves the defaults of NuonEnvironment::Init in place.
Hashes and source
in repoMD5 20becfdb9320

video_generic.vs

GLSL vertex shader

  • Path: nuance/video_generic.vs
  • Opened from the working directory, and the copy compiled into the binary is used when the file is absent. The release archives ship the file without the EMBED_HLSL guards (413 bytes).
Hashes and source
in repo built-in fallbackMD5 5944fea1ff20

video_m32_o32.fs

GLSL fragment shader, YCrCb to RGB conversion

  • Path: nuance/video_m32_o32.fs
  • Selected when UseCRTshader is disabled in nuance.cfg. Same lookup and fallback as video_generic.vs. The release copy is 6090 bytes.
Hashes and source
in repo built-in fallbackMD5 e23f4668fea6

video_m32_o32_crt.fs

GLSL fragment shader with CRT post-processing

  • Path: nuance/video_m32_o32_crt.fs
  • Selected when UseCRTshader is enabled, the shipped default. Same lookup and fallback as video_generic.vs. The release copy is 8052 bytes.
Hashes and source
in repo built-in fallbackMD5 2e1335cd9b14

FlashEEPROM.bin

Atmel AT49BV162A flash ROM image, 2 MB at 0xF0000000

  • Read by the FlashEEPROM constructor from the process working directory when the core is loaded, truncated to 2 MB, and written back by the destructor. The release archives ship one, and its content is the flash state of the session that produced it.
Source
in repo-

breakpoint.txt

Single breakpoint address, first line in hexadecimal

  • Read from the working directory by the standalone executables only: NuanceMain.cpp and NuanceMain_linux.cpp are excluded from the libretro build (CMakeLists.txt:214).
Source
missing standalone-

Next steps

Section titled “Next steps”
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Maintained by Abdess on GitHub. Report a problem.

Packs from release v2026.10.10, .

MIT for the tooling and metadata. BIOS and firmware files are third-party system software, preserved for personal backup, archival and interoperability.