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RetroBIOS

GnGeo-Pi

GnGeo-Pi emulates SNK Neo Geo MVS and SNK Neo Geo AES. It reads 10 files, 4 of them required: without a required file it does not start games. A required file is needed only by the machines that use it. Each file below cites the line of source code that reads it.

About this profile
Detail Value
Type standalone
Classification Community fork
Source https://github.com/ymartel06/GnGeo-Pi
Version 0.85
Revision ymartel06/GnGeo-Pi@b94571c6097b
Profiled 2026-10-20
Profile YAML, JSON
Cores gngeopi
Systems SNK Neo Geo MVS, SNK Neo Geo AES
Install this emulator's files

With RetroPie: the installer finds RetroPie and its BIOS folder, then downloads only the files GnGeo-Pi reads there and checks each one.

Open a terminal on the device. Or connect from a computer with SSH, a terminal over the network. Paste the line. Press Enter.

Terminal
curl -fsSL https://raw.githubusercontent.com/Abdess/retrobios/main/install.sh | sh -s -- --emulator gngeopi
Technical notes

Raspberry Pi build of Gngeo by Yannick Martel, imported as the Gngeo 0.8 tree of Mathieu Peponas (gngeo/configure.in:3) and released as 0.85. The repository is not a git fork of any Gngeo history. RetroPie builds gngeo/, installs it to its own prefix and launches it with "-i $romdir/neogeo -B <prefix>/neogeobios".

-B sets biospath, an option the code defines and never reads. The BIOS archive is opened from rompath, the -i directory, as neogeo.zip. The same archive is opened as the parent of every game whose definition names neogeo as parent, and a missing parent ends the load. ref: gngeo/src/conf.c:416-425, gngeo/src/roms.c:1217-1235,1364-1375

Members of neogeo.zip are found by exact name only, dr_load_bios passing no CRC. 000-lo.lo is read for every game. The board fix layer is read as sfix.sfx then sfix.sfix, unless the game's definition loads it itself. The 68K BIOS follows the system option (arcade by default) and the country option (europe by default): unibios reads uni-bios.rom from the archive or loose from rompath, home reads aes-bios.bin, and arcade reads vs-bios.rom, usa_2slt.bin, asia-s3.rom or sp-s2.sp1 for japan, usa, asia and any other country. A member that is not found ends the load. ref: gngeo/src/roms.c:1237-1308, gngeo/src/unzip.c:186-215, gngeo/src/conf.c:119-142, gngeo/src/emu.h:34-43

Game definitions come from gngeo_data.zip, the datafile installed to the package data directory, as rom/<game>.drv: 237 definitions, each giving the parent and every member with its region, size and CRC32. A game member is looked up by name or CRC32 in the game archive, then in the parent. A miss in the audio BIOS, fix BIOS or 68K BIOS regions is tolerated, any other miss ends the load. 58 definitions name a BIOS member: sfix.sfix (CRC32 c2ea0cfd) in the fix BIOS region, sm1.sm1 (CRC32 94416d67) in the audio BIOS region for neogeo, irrmaze and the svc bootlegs, and board BIOS images that live in the game's own archive (236-bios.bin for irrmaze, 271-bios.bin for kf2k3pcb, sp-4x.sp1 for ms5pcb and svcpcb). ref: gngeo/src/resfile.c:70-117, gngeo/src/roms.c:1347-1362,1428-1460, gngeo/src/roms.h:8-17,25-40

The CMC42 and CMC50 key tables are read from the same datafile, the older direct reads from the author's home directory being commented out. The datafile also holds the menu skin. ref: gngeo/src/neocrypt.c:618-656, gngeo/src/menu.c:535-537

Files

Section titled “Files”

10 files: 4 required, 6 optional. 3 more files come with the app.

By kind: 9 BIOS, 1 BIOS ZIPs and 3 game data.

File Required Hash
neogeo.zip for SNK Neo Geo MVS -
000-lo.lo for SNK Neo Geo MVS -
sfix.sfx for SNK Neo Geo MVS CRC32 c2ea0cfd
sp-s2.sp1 for SNK Neo Geo MVS -
vs-bios.rom no -
usa_2slt.bin no -
asia-s3.rom no -
aes-bios.bin no -
uni-bios.rom no -
sm1.sm1 no CRC32 94416d67
gngeo_data.zip with the app MD5 60f938bb73e1
rom/cmc42.xor with the app CRC32 86af55af
rom/cmc50.xor with the app CRC32 eb67fc2d

In this collection: 8 in repo and 2 missing.

Required

Section titled “Required”

neogeo.zip required for SNK Neo Geo MVS in repo BIOS ZIP

Neo Geo system ROMs

  • Opened from rompath, the ROM directory, for the BIOS and again as the parent archive of most games. Its absence ends the load with "Can't open BIOS". The container is never hashed.

000-lo.lo required for SNK Neo Geo MVS in repo in neogeo.zip

Zoom lookup table

  • Read by name for every game, and a miss ends the load.

sfix.sfx required for SNK Neo Geo MVS in repo in neogeo.zip

Board fix layer tiles

  • Size: 128.0 KB
  • CRC32: c2ea0cfd
  • Aliases: sfix.sfix
  • Read as sfix.sfx then sfix.sfix, 0x20000 bytes converted. Skipped when the game definition lists sfix.sfix itself, which it then finds by name or by CRC32 c2ea0cfd. The CRC is the one the shipped definitions carry.

sp-s2.sp1 required for SNK Neo Geo MVS in repo in neogeo.zip

MVS 68K BIOS, Europe

  • Default selection, arcade system with country europe or any value other than japan, usa and asia.

Optional

Section titled “Optional”
6 files

vs-bios.rom optional in repo in neogeo.zip

MVS 68K BIOS, Japan

  • Read when the system is arcade and the country japan.

usa_2slt.bin optional in repo in neogeo.zip

MVS 68K BIOS, USA

  • Read when the system is arcade and the country usa.

asia-s3.rom optional missing in neogeo.zip

MVS 68K BIOS, Asia

  • Read when the system is arcade and the country asia.

aes-bios.bin optional missing in neogeo.zip

AES 68K BIOS

  • Read when the system option is home.

uni-bios.rom optional in repo in neogeo.zip

Universe BIOS

  • Read when the system option is unibios, first from neogeo.zip, then as a loose file in rompath of which 0x20000 bytes are read. Any Universe BIOS release renamed to uni-bios.rom is accepted.

sm1.sm1 optional in repo in neogeo.zip

Audio board BIOS

  • Listed in the audio BIOS region by the neogeo, irrmaze, svcboot, svcplus, svcplusa and svcsplus definitions. A miss in that region is tolerated.

Comes with the app

Section titled “Comes with the app”
3 files

gngeo_data.zip comes with the app game data

Romset definitions, CMC key tables and menu skin

  • Installed to the package data directory by make install and named by the datafile option. Without a definition for the game the load ends with "Can't find rom driver".

cmc42.xor comes with the app game data in gngeo_data.zip

CMC42 graphics decryption key tables

cmc50.xor comes with the app game data in gngeo_data.zip

CMC50 graphics and M1 decryption key tables

Next steps

Section titled “Next steps”
.

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.