Capcom CP System III (CPS-3)

Capcom's last proprietary arcade platform (1996), before the move to the Naomi. Home of Street Fighter III, Red Earth/Warzard, JoJo. Architecture of CD-ROM + flash SIMMs + security cartridge — and the most feared suicide: when the cartridge battery dies, the game dies with it.

Identification

Field	Value
Manufacturer	Capcom
Years	1996 → 1999 (6 games)
System / family	CPS-3
Media	CD-ROM (SCSI) + flash SIMMs + security cartridge
Connector type	JAMMA
Resolution	384×224 (or 496×224 widescreen)
Colours	32,768 on screen (16.7M palette)

The 6 games

Red Earth / Warzard (1996), Street Fighter III: New Generation (1997), SFIII 2nd Impact (1997), JoJo's Bizarre Adventure (1998), SFIII 3rd Strike (1999), JoJo's Bizarre Adventure: Heritage for the Future (1999).

Architecture

Block	Component
CPU	Hitachi SH-2 (HD6417099) @ 25 MHz, integrated decryption
Storage	SCSI CD-ROM drive + Flash ROM SIMMs (up to 8 × 16 MB)
RAM	512 KB work, 512 KB sprite, 8 MB character, 256 KB colour…
Sound	16 stereo channels, 8-bit samples

Operation & security

1. The (encrypted) game data is on the CD.
2. At power-on it is loaded into the flash SIMMs.
3. The security cartridge holds the BIOS + the decryption keys, stored in battery-backed SRAM.

The "suicide"

When the cartridge battery dies, the keys are lost → the cartridge becomes unplayable (dead board). This is the CPS-3 suicide, reputedly severe.

• Exception: SFIII 2nd Impact used hard-coded default keys → it works again even with a dead battery.
• Crack: Andreas Naive reverse-engineered the encryption in June 2007 → emulation + "super cartridges" that bypass the security.

Solutions (preservation)

1. Replace the battery (cartridge still alive) Solder a fresh battery without cutting power to the keys (keep the SRAM powered during the swap) — otherwise suicide. On an already-dead cartridge, the battery alone isn't enough: you must reprogram (below).

2. Phoenix / no-battery BIOS After the crack (2007), decrypted BIOS/data or default keys are available → the cartridge runs without a battery. Requires reflashing the cartridge / SIMM ROMs.

3. CD-less / SD multi (the modern solution) The Darksoft CPS-3 kit replaces CD + cartridge + battery with SD storage: all CPS-3 games, no more suicide, no more CD drive (the mechanical weak point). Today it's the most reliable preservation route.

In short: a CPS-3 is preserved durably either battery-less (phoenix), or via an SD multi. Keeping an original cartridge alive requires permanent battery vigilance.

Common faults

Symptom	Likely cause	Lead
Dead cartridge / won't boot	Flat battery (suicide)	Phoenix / no-battery, or SD multi
CD load errors	Worn SCSI CD drive / damaged CD	Repair/replace drive, or SD multi
Corrupted graphics	Flash SIMMs / contacts	Reflash SIMMs, reseat
No image	Power / SH-2 / contacts	Base diagnosis

Conversions & mods

• SD multi (Darksoft): all CPS-3 games, no CD or battery.
• ⚠️ Do not host ROMs — method only.

→ CPS-3 converts guide (CD + cartridge + SIMM) · CPS-3 Darksoft multi

Emulation & FPGA

• MAME: emulation born of reverse-engineering (Bart Trzynadlowski, Andreas Naive) — SH-2, program encryption, CD-ROM stream, SIMMs.
• FPGA / MiSTer: no core to date — SH-2 + CD-ROM + large SIMMs exceed the DE10-Nano's budget. Preservation = MAME + no-CD / no-battery hardware solutions (see CPS-3 converts).

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.

• Anti-suicide — the priority mod 🟠: this platform suicides (key/program held by a battery). Replacing the battery without cutting power only postpones the problem; the durable route is de-suiciding → conversions and de-suiciding → 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 📺: ~15.73 kHz / 59.6 Hz — standard resolution, a classic 15 kHz chassis is fine → tri-sync and upscalers. (Computed from the MAME sources — capcom/cps3.cpp — pixel clock ÷ htotal.)
• FPGA / emulation: see the Emulation & FPGA section below.

Repair (flash, not EPROM)

The CPS-3 stores the game on flash SIMMs (no classic program EPROM) + an encrypted cartridge/CD. ⚠ Severe suicide (battery → key lost). SIMM/de-suicide detail: CPS-3 converts.

Repair — security & battery (technician)

• Battery-backed security cartridge: the CPS-3 decrypts via a battery-backed key (in the cartridge) → flat battery = suicide (dead game, healthy hardware). See backup batteries; remade SIMMs are possible (preservation).
• Flash SIMMs: game data lives on Flash (no EPROM), installed from the CD — see the flash section above.
• SCSI CD-ROM drive: mechanism/laser = a weak point → optical cleaning.
• Capacitors: recap PSU + audio filtering.

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

Photos / assets

(To add: base board, security cartridge + battery, SIMMs, CD drive.)

Sources & attribution

• Wikipedia — CP System III (architecture, security, suicide, 2007 crack) — CC-BY-SA — https://en.wikipedia.org/wiki/CP_System_III
• Darksoft — CPS-3 multi kit — to reference
• Arcade-Projects — CPS-3 de-suicide / multi — to reference

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.