# CP System III
**CP System III** (CPシステムIII), commonly abbreviated CPS3, is an arcade system board released by Capcom in 1996 as the third and final entry in its [CP System](https://www.edgepedia.org/cp-system) series of proprietary arcade hardware[1](https://www.arcade-museum.com/Videogame/cp-system-iii). It departed from its predecessors by storing games on CD-ROM and loading them into flash memory on the board, and by concentrating the main processor and the game's encryption keys in a battery-backed security cartridge[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). Only six games were released for it, all one-on-one fighting games, and Capcom stopped manufacturing the hardware after 1999[3](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth).
| Key fact | Detail |
|---|---|
| Manufacturer and year | Capcom, 1996[1](https://www.arcade-museum.com/Videogame/cp-system-iii) |
| First release | Red Earth (War-Zard in Japan), 21 November 1996[3](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth) |
| CPU | Hitachi SH-2 derivative (thought to be based on the HD6417099 variant) with built-in encryption, housed in the security cartridge[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp) |
| Game storage | SCSI CD-ROM drive plus custom 72-pin flash SIMMs on the main board; program SIMMs are 64 Mbit, graphics and sound SIMMs are 128 Mbit[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp) |
| Copy protection | Battery-backed decryption keys in the security cart; tampering or battery loss erases the keys and kills the cart[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp) • [4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/) |
| Library | Six games: Red Earth/War-Zard, the Street Fighter III trilogy, JoJo's Venture, and JoJo's Bizarre Adventure[3](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth) • [1](https://www.arcade-museum.com/Videogame/cp-system-iii) |
## Architecture
The system consists of a single main board with several custom ASICs, a SCSI CD-ROM drive, and a plug-in security cartridge[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). Unlike the CPS2, which split the hardware into separate A and B boards, the CPS3 consolidated everything onto one smaller board[4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/).
**Game loading.** When a game is first powered up, the contents of the CD are copied into a bank of custom 72-pin SIMMs on the main board; these modules hold flash ROM chips rather than RAM, and the SIMMs store the entire contents of the CD[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). This design maximizes the life of the CD drive, since the disc is only read during installation[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). The SIMM slots in positions 1 and 2 hold 64 Mbit modules for program code, while positions 3 through 7 hold 128 Mbit modules for graphics and sound data; not every game populates every slot, so flash times vary by game[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). Swapping games requires the matching security cartridge, the game's CD, and the correctly populated SIMMs; after a swap the board asks whether to reprogram the SIMMs, a process that takes about 25 to 30 minutes, after which subsequent power-ups boot immediately[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp).
**Security cartridge.** The cartridge contains a boot flash ROM, NVRAM, and the system's main CPU, a custom Capcom part containing battery-backed decryption keys[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). The CPU is a Hitachi SH-2 derivative, thought to be based on the HD6417099 SH2 variant with built-in encryption, and decapping showed a SH2 core based on the Hitachi SH7010-series (SH7014) with static RAM on the die holding the decryption key[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). The CPU will not run standard unencrypted SH2 code, and the flash ROM in the cart holds an encrypted boot program that the CPU decrypts itself[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp).
Because the cart CPU is always powered by the battery, it continuously monitors for tampering: voltage fluctuation, voltage dropping, or removal of the cart while the board is powered causes it to immediately erase the decryption key in its static RAM, killing the cartridge[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). Transistors on the cartridge PCB switch the CPU between battery and main power to extend battery life[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). A typical battery is a 1/2AA lithium cell, and owners are advised to replace it about once every 5 years[5](https://wiki.hardedge.org/index.php/CPSIII) • [6](https://junkerhq.net/xrgb/index.php/CPS-3). A dead cart shows a scrambled screen of garbage-colored pixels or a black or single-colored screen at boot[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp).
## Copy protection and its consequences
The security cart provided on-the-fly decryption of game data and was very successful at preventing pirate copies; the custom CPU also made the cartridges expensive and hard to duplicate[4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/). The cost was serviceability. When a cart died, the game stopped working, and for a long time only Capcom could revive a dead cartridge, with failed boards sent to Capcom for repair[4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/) • [7](https://forums.arcade-museum.com/threads/school-me-on-cps3-street-fighter-3rd-strike.217479/). Battery replacement on a CPS3 cart requires more skill than on a CPS2 board because the battery is soldered in place, and first-generation carts (Red Earth, Street Fighter III: New [Generation](https://www.edgepedia.org/generation)) add an extra wire that complicates the job[5](https://wiki.hardedge.org/index.php/CPSIII). The carts are also extremely static-sensitive, and many failed simply from handling the PCB or from power fluctuations while flashing the SIMMs[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp).
## Games
Capcom released six games for the system between 1996 and 1999[3](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth) • [8](https://pantspantsrevolution.com/cps3-core-running-games/):
- Red Earth (War-Zard), November 1996, the launch title and the only CPS3 game never released for home consoles or compilations[3](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth)
- [Street Fighter III](https://www.edgepedia.org/street-fighter-iii): New Generation (1997)[9](https://github.com/mamedev/historic-mess/blob/master/src/mame/drivers/cps3.c)
- Street Fighter III 2nd Impact: Giant Attack (1998)[9](https://github.com/mamedev/historic-mess/blob/master/src/mame/drivers/cps3.c)
- Street Fighter III 3rd Strike: Fight for the Future (1999)[9](https://github.com/mamedev/historic-mess/blob/master/src/mame/drivers/cps3.c)
- JoJo's Venture (1998)[9](https://github.com/mamedev/historic-mess/blob/master/src/mame/drivers/cps3.c)
- [JoJo's Bizarre Adventure](https://www.edgepedia.org/jojos-bizarre-adventure): Heritage for the Future (1999)[9](https://github.com/mamedev/historic-mess/blob/master/src/mame/drivers/cps3.c)
Red Earth blended fighting game mechanics with RPG elements, including a password system for carrying character progress between sessions[3](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth). The Street Fighter III games were the platform's flagship titles, and the hardware delivered 2D visuals noted for animation, fluidity, and effects[10](https://as.com/meristation/2018/05/29/analisis/1527577200_176078.html). Street Fighter III 3rd Strike also exists in a No-CD version in which the game data is stored on the board itself[5](https://wiki.hardedge.org/index.php/CPSIII).
## Commercial performance
The CPS3 was a commercial failure in arcades, and Capcom's apparent plans for a larger library, as it had with CPS2, were canceled[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). Possible reasons recorded in the MAME driver documentation include the games being essentially 2D at a time when 3D games were drawing operator interest, the system's high cost compared with other options, a rumor that the system was difficult to program for, and operator frustration with the fragile security carts[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp).
## Cabinet connection
The board delivers standard JAMMA through its edge connector and can be wired directly to a cabinet or supergun; six-button Capcom fighting games use an additional connector, the JAMMA+ arrangement, wired through a so-called kick harness for the three extra buttons[5](https://wiki.hardedge.org/index.php/CPSIII) • [1](https://www.arcade-museum.com/Videogame/cp-system-iii). The board has an on-board stereo amplifier and outputs mono through the JAMMA edge; stereo requires an amplifier such as Capcom's Q-Sound system[5](https://wiki.hardedge.org/index.php/CPSIII) • [4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/). Most units shipped with a [Panasonic](https://www.edgepedia.org/panasonic) 6x SCSI CD-ROM drive, model CR-504, which can be replaced with any standard SCSI drive[5](https://wiki.hardedge.org/index.php/CPSIII).
## Emulation and revival
The MAME driver credits decryption to Andreas Naive, with the driver by David Haywood and sound emulation by Philip Bennett, among others[2](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp). Before that point, MAME could not run CPS3 games at all[4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/).
A community modification by DarkSoft64 allows a dead security cart to be resurrected, though not to its original state: a replacement BIOS runs unencrypted game images, and the same cartridge can then play any of the six games without swapping carts[4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/). Flashing a game from a multi-game CD with this mod can take up to 40 minutes[4](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/). An FPGA implementation, Jotego's JTCPS3 core, has also reached the point of running Red Earth and Street Fighter III: New Generation[8](https://pantspantsrevolution.com/cps3-core-running-games/).
## References
1. [CP System III - Videogame by Capcom, International Arcade Museum](https://www.arcade-museum.com/Videogame/cp-system-iii)
2. [cps3.cpp, MAME source, MAMEdev GitHub](https://github.com/mamedev/mame/blob/master/src/mame/capcom/cps3.cpp)
3. [Red Earth (Game), Giant Bomb](https://wiki-origin.giantbomb.com/wiki/Games/Red_Earth)
4. [Capcom CPS3 System Darksoft Bios Mods, 8Bitplus](https://8bitplus.co.uk/articles/capcom-cps3-system-darksoft-bios-mods/)
5. [CPSIII, Hardedge Wiki](https://wiki.hardedge.org/index.php/CPSIII)
6. [CPS-3, Classic Console Upscaler Wiki](https://junkerhq.net/xrgb/index.php/CPS-3)
7. [School me on CPS3, Museum of the Game forums](https://forums.arcade-museum.com/threads/school-me-on-cps3-street-fighter-3rd-strike.217479/)
8. [Jotego's CPS3 FPGA core is running games, Pants Pants Revolution](https://pantspantsrevolution.com/cps3-core-running-games/)
9. [cps3.c, historic-mess MAME source, MAMEdev GitHub](https://github.com/mamedev/historic-mess/blob/master/src/mame/drivers/cps3.c)
10. [Street Fighter 30th Anniversary Collection, análisis, MeriStation](https://as.com/meristation/2018/05/29/analisis/1527577200_176078.html)
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*Topic: Encyclopedia › Technology and the built world › Computing and digital systems › Computer hardware › Boards, peripherals & form factors › Motherboards & form factors › Motherboard manufacturers*
*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license