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Sega Chihiro

The NAOMI's successor (2002), based on Microsoft's Xbox. Pentium III + GeForce 3, GD-ROM media loaded into RAM, boot from a DIMM board (SEGABOOT). OutRun 2, Virtua Cop 3, Ghost Squad, The House of the Dead III… The Xbox kinship helps modern emulation.

Identification

Field Value
Manufacturer Sega
Year 2002 (The House of the Dead III)
Base Microsoft Xbox (motherboard + add-on boards)
Media GD-ROM + DIMM board (loaded into RAM)
I/O JVS

Architecture (≈ Xbox)

Block Chip Clock Role
CPU Intel Pentium III 733 MHz Xbox base
GPU NVIDIA NV2A (GeForce 3) 3D rendering
RAM 128 MB DDR double an Xbox (64 MB) — an arcade specific
Media GD-ROM (like NAOMI/Triforce) copied whole to RAM at boot → no load times
Boot DIMM board (SEGABOOT XBE) always boots from the DIMM, never another source

Security & preservation

  • DIMM boot: the Chihiro boots via a SEGABOOT (XBE) on the DIMM board; the GD-ROM game is copied to RAM.
  • DIMM media + battery: logic close to the NAOMI (DIMM board), hence the importance of imaging the GD-ROMs and handling the DIMM battery.
  • Emulation: the Xbox kinship helps — Chihiro support is progressing in Xbox emulators (Cxbx-Reloaded/xemu branches); GD-ROM imaging is the base.
  • → Preservation & modernisation (GD-ROM/netboot, no-battery, MiSTer).

Notable games

The House of the Dead III (2002), OutRun 2 / OutRun 2 SP, Virtua Cop 3, Ghost Squad, Crazy Taxi High Roller, Sega Golf Club, Ollie King, Mahjong…

Faults & repair

Xbox-class hardware → Xbox repairs apply + arcade specifics:

Symptom Likely cause Lead
Won't boot DIMM board / SEGABOOT, battery DIMM diagnosis; image before it fails
GD not read Worn GD-ROM drive Repair/image; SD solutions
Reboots PSU capacitors (like Xbox) Recap
Lost settings RTC battery / config Replace
Dead controls JVS I/O / harness JVS diagnosis

Modernisation & mods

The common ground for every JAMMA board

Video, power, control panel and upscalers depend on the cabinet rather than the board: everything is centralised in Modernising a cabinet. To run the board outside a cabinet (at home, on a display): supergun.

  • Battery 🟢: a save battery is fitted (settings/counters/RTC). A leaking battery corrodes traces — check and replace it before it leaks → save batteries.
  • Optical storage 🟡: the drive is the number-one wear part. Modern routes: an ODE, netboot, or replacement by flash storage depending on the platform → PCB preservation hub.
  • Scan rate 📺: derived from a home console (see the architecture above): 480i/480p output, i.e. ~15.7 kHz interlaced and ~31.5 kHz progressive. ⚠️ A 15 kHz chassis only covers the interlaced mode — plan for a tri-sync. (Derived from the platform, not measured from MAME.) → tri-sync and upscalers.
  • FPGA / emulation: see the Emulation & FPGA section below.

Repair (technician)

  • Xbox base: the same faults as an Xbox — the clock capacitor that leaks (first-gen Xbox) → remove/clean it before it eats the board; capacitors, PSU.
  • DIMM board: boots always from the DIMM; content in RAM (battery → reload).
  • GD-ROM: drive/laser → ODE mods.
  • Media board / SEGABOOT: a key/media-board dependency.

→ Methods: PCB fault-finding · Recap · Backup batteries · Traces & vias

Original manuals for games on this platform ✅

Manufacturer manuals for games running on this board. Beyond the instructions, they very often carry the full DIP settings, the connector pinout, the test procedure, the parts list and the expected voltages.

→ Full catalogue: service manuals, wiring & game manuals

Emulation & FPGA

  • Emulation: Xbox emulators (xemu / Cxbx-Reloaded) with improving Chihiro support. No FPGA core (a full PC).

Lineage

Successor to the NAOMI; a console-based cousin of the Triforce (GameCube) and the Lindbergh (PC).

Photos / assets

(To add: Chihiro board, DIMM board, GD-ROM drive, JVS I/O.)

Sources & attribution

Review & corrections

How this space is used

Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.

Reading is open to everyone; posting requires signing in with Discord. Reports from the wiki's declared reviewers are handled first; anyone else's are read too, but go through a human before anything is changed.