Editing CP System III (section)

==History==
The CP System III became the final arcade system board to be designed by Capcom. It features a security mechanism; games are supplied on a CD, which contains the encrypted game contents, and a security cartridge containing the game [[BIOS]] and the [[SuperH|SH-2]] CPU<ref name="mamedriver">{{Cite web|url=https://github.com/mamedev/mame|title=mamedev/mame|website=[[GitHub]]|access-date=2020-03-01}}</ref> with integrated decryption logic, with the per-game key stored in battery-backed [[Static random-access memory|SRAM]]. Capcom chose the CD medium in order to keep down the price of the system.<ref>{{cite magazine|date=February 1997|title=Introducing... Red Earth|url=https://archive.org/details/Official_Sega_Saturn_Magazine_016/page/n97/mode/2up|magazine=[[Sega Saturn Magazine]]|publisher=[[Emap International Limited]]|issue=16|page=98}}</ref>

In a change from its predecessors, the CP System III consists of a single board instead of two separate boards. The board contains components common to all CP System III games, and includes a slot for the security cartridge. The games themselves are stored on a CD instead of on a separate board, which is then readable by the provided [[SCSI]] CD-ROM drive that is connected to the main board. The CP System III has extensive sprite scaling capabilities that all games for the system used. It does not contain the [[QSound]] sound chip used on its predecessor, the CP System II, and in its place is a custom 16-channel stereo sound chip. One of the unique features of the CP System III is [[widescreen]] support for certain games; only one game has officially made use of this feature, which is ''[[Street Fighter III: 2nd Impact]]''.

When the CP System III board is first powered on, the contents of the CD are loaded into a bank of [[Flash ROM]] [[SIMM]]s on the motherboard, where it is executed. The program code is then decrypted at run time via the security cartridge. The security cartridge is sensitive to any sort of tampering, which will result in the decryption key being erased and the cartridge being rendered useless. Games become unplayable when the security cartridge has been tampered with or when the battery inside the security cartridge dies. The lone exception is ''Street Fighter III: 2nd Impact'', which uses a default set of decryption keys that are written to dead cartridges on boot,<ref name=mamedriver/> making it the few, if not the only CPS-3 games prevalent after support was dropped, due to its immunity to cartridge tampering or suicide.

In June 2007, the encryption method was [[Reverse engineering|reverse-engineered]] by Andreas Naive,<ref>{{Cite web|url=http://andreasnaive.blogspot.com/2007/06/cps-3-7.html?m=1|title=CPS-3 (7)|date=June 11, 2007|website=andreasnaive.blogspot.com|url-status=live|archive-url=https://web.archive.org/web/20070717063214/http://andreasnaive.blogspot.com/|archive-date=July 17, 2007}}</ref> making [[Video game console emulator|emulation]] possible.<ref name=mamedriver/> Later developments led to the eventual bypassing of the suicide and security routines of the games as well as a development of a so-called "super cartridge" capable of running all CPS-3 games.<ref>{{cite web| url=http://64darksoft.blogspot.com/2013/08/one-bios-to-rule-them-all-and-one-cdto.html|title=Breaking CPS3: One BIOS to rule them all .....and One CD......to play them on and on. (UPDATE 7)|date=August 11, 2013|website=64darksoft.blogspot.com}}</ref>

Capcom ceased manufacturing the CP System III hardware after 1999. Capcom ended most of the technical support for the hardware and its games on March 31, 2015.<ref name="csend">{{cite web|url=https://www.capcom.co.jp/arcade/news/operator/20140930.html|title=弊社基板製品保守サービス業務終了のご案内|publisher=Capcom|date=2014-09-30|accessdate=2024-04-25}}</ref> Battery replacements ended on February 28, 2019,<ref name="csend2">{{cite web|url=https://www.capcom.co.jp/arcade/news/operator/201811.html|title=弊社製品のサービス対応終了に関するご案内|publisher=Capcom|date=2018-11-12|accessdate=2024-04-25}}</ref> ending all official support of the CP System III hardware and software.