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PCSX2 - RetroBIOS
Type standalone
Source https://github.com/PCSX2/pcsx2
Version Git
Profiled 2026-03-18
Cores pcsx2
Systems sony-playstation-2
BIOS directory bios/
BIOS detection romdir
BIOS selection automatic
Memory layout

ROM:

- **offset:** 0x1FC00000
- **size:** 4 MB
- **purpose:** Main BIOS binary

ROM1:

- **offset:** ROM + 4MB
- **size:** 4 MB
- **purpose:** DVD player

ROM2:

- **offset:** ROM + 8MB
- **size:** 4 MB
- **purpose:** Chinese ROM extension
Regions

J:

- **zone:** Japan
- **id:** 0

A:

- **zone:** USA
- **id:** 1

E:

- **zone:** Europe
- **id:** 2

H:

- **zone:** Asia
- **id:** 4

C:

- **zone:** China
- **id:** 6

T:

- **zone:** T10K/COH-H
- **id:** 8

X:

- **zone:** Test
- **id:** 9

P:

- **zone:** Free
- **id:** 10
NVM layout

format_0:

- **applies_to:** BIOS v0.00+
- **biosVer:** 0
- **config0:** 640
- **config1:** 768
- **config2:** 512
- **consoleId:** 456
- **ilinkId:** 448
- **modelNum:** 416
- **regparams:** 384
- **mac:** 408

format_1:

- **applies_to:** BIOS v1.70+
- **biosVer:** 326
- **config0:** 624
- **config1:** 688
- **config2:** 512
- **consoleId:** 496
- **ilinkId:** 480
- **modelNum:** 432
- **regparams:** 384
- **mac:** 408
Common BIOS filenames
  • SCPH-10000_BIOS_V1_JAP_100.BIN
  • SCPH-15000_BIOS_V3_JAP_120.BIN
  • SCPH-30000_BIOS_V4_JAP_150.BIN
  • SCPH-30001R_BIOS_V7_JAP_160.BIN
  • SCPH-30004R_BIOS_V7_JAP_160.BIN
  • SCPH-35000_BIOS_V5_JAP_160.BIN
  • SCPH-50000_BIOS_V9_JAP_170.BIN
  • SCPH-50004_BIOS_V9_JAP_170.BIN
  • SCPH-70000_BIOS_V12_JAP_200.BIN
  • SCPH-75000_BIOS_V14_JAP_220.BIN
  • SCPH-77000_BIOS_V14_JAP_220.BIN
  • SCPH-90000_BIOS_V18_JAP_230.BIN
  • SCPH-30001_BIOS_V4_USA_150.BIN
  • SCPH-39001_BIOS_V6_USA_160.BIN
  • SCPH-50001_BIOS_V9_USA_170.BIN
  • SCPH-50003_BIOS_V9_USA_170.BIN
  • SCPH-70002_BIOS_V12_USA_200.BIN
  • SCPH-70004_BIOS_V12_USA_200.BIN
  • SCPH-70012_BIOS_V12_USA_200.BIN
  • SCPH-75001_BIOS_V14_USA_220.BIN
  • SCPH-77001_BIOS_V14_USA_220.BIN
  • SCPH-90001_BIOS_V18_USA_230.BIN
  • SCPH-30002_BIOS_V4_EUR_150.BIN
  • SCPH-30003_BIOS_V4_EUR_150.BIN
  • SCPH-30004_BIOS_V4_EUR_150.BIN
  • SCPH-39002_BIOS_V6_EUR_160.BIN
  • SCPH-39003_BIOS_V6_EUR_160.BIN
  • SCPH-39004_BIOS_V6_EUR_160.BIN
  • SCPH-50002_BIOS_V9_EUR_170.BIN
  • SCPH-50004_BIOS_V9_EUR_170.BIN
  • SCPH-70002_BIOS_V12_EUR_200.BIN
  • SCPH-70003_BIOS_V12_EUR_200.BIN
  • SCPH-70004_BIOS_V12_EUR_200.BIN
  • SCPH-70008_BIOS_V12_EUR_200.BIN
  • SCPH-75002_BIOS_V14_EUR_220.BIN
  • SCPH-75003_BIOS_V14_EUR_220.BIN
  • SCPH-75004_BIOS_V14_EUR_220.BIN
  • SCPH-77002_BIOS_V14_EUR_220.BIN
  • SCPH-77003_BIOS_V14_EUR_220.BIN
  • SCPH-77004_BIOS_V14_EUR_220.BIN
  • SCPH-90002_BIOS_V18_EUR_230.BIN
  • SCPH-90003_BIOS_V18_EUR_230.BIN
  • SCPH-90004_BIOS_V18_EUR_230.BIN
  • SCPH-50009_BIOS_V9_HK_170.BIN
  • SCPH-70005_BIOS_V12_HK_200.BIN
  • SCPH-70006_BIOS_V12_HK_200.BIN
  • SCPH-70008_BIOS_V12_HK_200.BIN
  • SCPH-50009_BIOS_V9_CHN_170.BIN
  • SCPH-70006_BIOS_V12_CHN_200.BIN
Technical notes

PCSX2 is filename-agnostic for the main BIOS. Detection relies on romdir structure parsing inside the binary itself, not on filename or extension. Any file between 4-8 MB with a valid romdir (containing at least RESET and ROMVER entries) is accepted.

The ROMVER entry encodes: version (2+2 digits), region letter, console/devel flag, build date (YYYYMMDD), and is used to determine the BIOS description and region.

Companion files (.nvm, .mec) are auto-created with sane defaults if missing. ROM1/ROM2 are silently skipped if not found - only the main BIOS binary is strictly required.

PCSX2 no longer ships as a libretro core in official builds. The standalone emulator is the primary distribution channel.

Devel console BIOSes (< ~2.3 MB) lack the OSD and are handled with NoOSD=true flag.

7 files | 1 required, 6 optional | 0 in repo, 7 missing | 3 with HLE fallback

<user-selected>.bin -required, missing from repo

  • Source: pcsx2/ps2/BiosTools.cpp:258-282
  • Pattern: *
  • Size range: 4MB-8MB
  • PCSX2 does not mandate a specific filename. It scans the entire bios/ directory for any file between 4-8 MB that contains a valid romdir structure (RESET + ROMVER entries). Common filenames follow the SCPH-XXXXX_BIOS_VYYY_REGION_ZZZ.BIN convention but this is not enforced. The file is loaded into the 4 MB ROM region of EE memory.

<biosname>.rom1 -optional, missing from repo

  • Size: max 4.0 MB
  • Source: pcsx2/ps2/BiosTools.cpp:214-241
  • Pattern: {biosname}.rom1 or {biosbase}.rom1
  • DVD player ROM. Loaded via LoadExtraRom("rom1"). PCSX2 tries two naming patterns: 1) Full bios path + ".rom1" appended (e.g. scph70004.bin.rom1) 2) Bios path with extension replaced (e.g. scph70004.rom1) Mapped to EE memory at ROM1 region (0x1FC00000 + 4MB offset). Contains DVD player and region detection data (DVDID).

<biosname>.rom2 -optional, missing from repo

  • Size: max 4.0 MB
  • Source: pcsx2/ps2/BiosTools.cpp:214-241
  • Pattern: {biosname}.rom2 or {biosbase}.rom2
  • Chinese ROM extension. Loaded via LoadExtraRom("rom2"). Same naming convention as rom1: tries appended extension first, then replaced extension. Only present on Chinese region consoles.

<biosname>.nvm -optional, HLE available, missing from repo

  • Size: 1.0 KB
  • Source: pcsx2/CDVD/CDVD.cpp:160-238
  • Pattern: {biosbase}.nvm
  • EEPROM / NVRAM data. Path derived from BiosPath with extension replaced to ".nvm" (cdvdGetNVRAMPath). Contains console configuration: language, timezone, iLink ID, region parameters, OSD settings. Auto-created with defaults if missing. Two NVM layouts exist: v0.00+ (biosVer 0x000) and v1.70+ (biosVer 0x146).

<biosname>.mec -optional, HLE available, missing from repo

  • Size: 4 B
  • Source: pcsx2/CDVD/CDVD.cpp:190-204
  • Pattern: {biosbase}.mec
  • Mechacon (mechanism controller) version file. 4 bytes containing the mecha version as a u32 value. Auto-created with DEFAULT_MECHA_VERSION (0x00020603) if missing. Path derived from BiosPath with extension replaced to ".mec".

<custom>.irx -optional, missing from repo

  • Source: pcsx2/ps2/BiosTools.cpp:243-256,384-385
  • Pattern: *.irx
  • Custom IOP Reboot eXecutable module. Loaded into ROM at offset 0x3C0000 if EmuConfig.CurrentIRX is set (path length > 3). Injected at IOP reset (PC=0x1630). Used for debugging/development, not needed for normal operation.

eeprom.dat -optional, HLE available, missing from repo

  • Size: 64 B
  • Source: pcsx2/DEV9/DEV9.cpp:110-160
  • DEV9 (network adapter / HDD expansion bay) EEPROM data. Fixed filename "eeprom.dat" opened from working directory. Contains network adapter configuration. Falls back to built-in defaults if file not found. Only relevant when using DEV9 features (online play, HDD).

Generated on 2026-03-25T14:56:43Z