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RetroBIOS

xemu Chihiro

xemu Chihiro emulates Sega Chihiro. It reads 7 files, 5 of them required: without a required file it does not start games.

About this profile
Detail Value
Type standalone
Classification Community fork
Source https://github.com/Tovarichtch/xemu
Upstream https://github.com/xemu-project/xemu
Version 0.8.134-406-g0d44d803b2
Revision Tovarichtch/xemu@98fbd75dd0f3, xemu-project/xemu@25e1ee2fd59a, branch perf-experimental
Profiled 2026-10-20
Profile YAML, JSON
Cores xemu-chihiro
Systems Sega Chihiro
Install this emulator's files

With RetroBat: the installer finds RetroBat and its BIOS folder, then downloads only the files xemu Chihiro 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://raw.githubusercontent.com/Abdess/retrobios/main/install.ps1))) --emulator xemu-chihiro
Technical notes

Tovarichtch's fork of xemu that adds the Sega Chihiro machine: the media board, the AN2131 and its 8051 firmware, JVS, the drive boards, the card readers and the network board. RetroBat ships the build whose version string is 0.8.134-406-g0d44d803b2, the "Source code release and playtest v2" commit this profile is pinned to, on the perf-experimental branch (the one with the fork's NV2A and CPU work). Batocera builds the same fork at a later commit.

RetroBat runs this emulator only as a Chihiro: the launcher sets the Chihiro path whenever the emulator is xemu-chihiro. It writes chihiro.roms.bios_path as bios/chihiro/chihiro_xbox_bios.bin, else bios/chihiro_xbox_bios.bin, and clears the media board and EEPROM paths so the emulator takes them from the folder of the BIOS. ref: emulatorLauncher Generators/Xemu.Generator.cs:48, 413-444

A Chihiro boots its own BIOS only, never the Xbox flash or MCPX boot ROM set for the Xbox machine: the Chihiro BIOS is an MCPX X2 image with its boot ROM built in. The BIOS must be 512 KiB with the SHA-1 MAME lists, else the machine stays paused with an error. ref: system/vl.c:3110-3135, 3169-3190, hw/xbox/chihiro/chihiro.c:2280-2292

The media board flash and the three serial EEPROMs come from the settings when set, else from the folder of the BIOS. The flash is tried as fpr21042_m29w160et.bin, fpr-23887_29lv160te.ic4, then fpr-23887.bin, each in that folder and then in its parent, and any size up to 4 MiB is read. The EEPROMs must have their exact size or they count as absent. Any of the five files missing keeps the machine paused with a message naming it. ref: hw/xbox/chihiro/chihiro.c:2259-2401, system/vl.c:3195-3241

The Xbox EEPROM is not a file to supply for a Chihiro: chihiro_eeprom.bin is generated with the debug key in the data directory and written back. The VM snapshots, the per game saves, the DIMM system area and the card images are written by the emulator too. Booting an Xbox disc with this build reads the same files as upstream xemu (emulators/xemu.yml), which RetroBat never asks it to do. ref: system/vl.c:2978-3001

The network firmware of the DIMM board is read only from the setting chihiro.roms.net_firmware_path, which RetroBat does not write. Without it the board reports version 3.17. Linked cabinets need it to run the network board, and network titles check the version it reports (OutRun 2 SP, Gundam). ref: hw/xbox/chihiro/chihiro.c:363-400, 491-513, config_spec.yml:908-915

Files

Section titled “Files”

7 files: 5 required, 2 optional.

File Required Hash
chihiro/chihiro_xbox_bios.bin yes SHA1 b700b0041af8
chihiro/fpr21042_m29w160et.bin yes -
chihiro/ic10_g24lc64.bin yes -
chihiro/pc20_g24lc64.bin yes -
chihiro/ic11_24lc024.bin yes -
chihiro/fpr-23887_29lv160te.ic4 no -
ver1305.bin no -

In this collection: 7 in repo and 0 missing.

Required

Section titled “Required”

chihiro_xbox_bios.bin required in repo

Chihiro BIOS

  • RetroBat also looks for it at the root of the bios folder. The other Chihiro files are then read from the same folder.

fpr21042_m29w160et.bin required in repo

Media board flash ROM (SEGABOOT)

  • First of the three names tried. The SEGABOOT version is read from the second megabyte and the board serial from the MBDT header at 0xFFE00.

ic10_g24lc64.bin required in repo

Base board QC EEPROM

pc20_g24lc64.bin required in repo

Base board SC EEPROM

ic11_24lc024.bin required in repo

Base board configuration EEPROM

Optional

Section titled “Optional”
2 files

fpr-23887_29lv160te.ic4 optional in repo

Media board flash ROM, later revision

  • Path: chihiro/fpr-23887_29lv160te.ic4
  • System: Sega Chihiro
  • Size: max 4.0 MB
  • Aliases: fpr-23887.bin
  • Read in place of fpr21042_m29w160et.bin when that one is absent, under either name.

ver1305.bin optional in repo

DIMM board network firmware 13.05

  • Opened only from the path set in the settings. Its version is the word after the FIRM_VERSION is here! mark.

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.