CP System III

• 1. Introduction

  ›

  The CP System III was an arcade board built to destroy its own key if anyone tampered with it. Capcom also called it the Capcom Play System 3, or CPS-3 for short. It followed the CP System and the CP System II, and its debut game was Red Earth in 1996. That design raises three questions. Why did Capcom trade daughterboards for compact discs? What exactly was the lock protecting? And what becomes of a machine that guards itself so fiercely once its maker stops looking after it?

  128

• 2. Discs Instead of Daughterboards

  ›

  Earlier Capcom systems spread their hardware across two boards, but the CP System III fits everything on one. That single board carries the parts common to every game on the platform. The games themselves arrive on a CD, not on a daughterboard. A SCSI CD-ROM drive, supplied with the system, plugs into the main board and reads the disc. Capcom picked the CD format to keep the price of the system down.

  Operators could still swap games without altering the core hardware, just as with the older boards. When the board is first powered on, the contents of the disc are copied into a bank of Flash ROM SIMMs on the motherboard. The game runs from there. The amount of Flash ROM varies, up to eight times 16 MB.

  The disc, however, is useless on its own. Every game also shipped with a cartridge of its own, and that cartridge holds the real secret.

  145

• 3. A Cartridge That Kills Itself

  ›

  Inside each security cartridge sits the game BIOS and an SH-2 processor with decryption logic built in. The per-game key lives in battery-backed SRAM. The disc holds only encrypted game contents, so the program code stays scrambled until the cartridge unscrambles it while the game is running.

  The cartridge reacts badly to interference. Any sign of tampering causes the decryption key to be erased, and the cartridge is then rendered useless. The same fate follows when the battery inside the cartridge runs out. In either case the game can no longer be played.

  One title escapes this rule. Street Fighter III: 2nd Impact uses a default set of decryption keys, and the board writes them back to dead cartridges every time it boots. That makes it immune to tampering and to battery death. It is one of the few CPS-3 games, if not the only one, still common after official support was dropped.

  145

• 4. What the Board Could Do

  ›

  At the heart of the board is a Hitachi HD6417099, an SH-2 chip running at 25 MHz. Around it sit 512 KB of work RAM, 512 KB of sprite RAM, 8 MB of character RAM, 256 KB of color RAM and 32 KB of SS RAM.

  On screen, the system improved on the CP System II in both the number of colors and the number of sprites. It offered a palette of 16 million shades, with 32,768 of them visible at once. It could track up to 1024 objects, and every game used its native sprite scaling. Backgrounds had four scroll layers, plus a fifth layer reserved for text such as the score.

  The QSound chip from the previous system gave way to a custom sound chip with 16 stereo channels. Standard output measured 384 by 224 pixels. A widescreen mode of 496 by 224 pixels existed too, yet Street Fighter III: 2nd Impact is the only game that officially used it.

  13

• 5. Six Fighting Games

  ›

  Red Earth reached arcades on the 21st of November 1996, and Japanese players knew it as War-Zard. Street Fighter III: New Generation followed on the 4th of February 1997. Both were head-to-head fighters, which describes the entire library of the platform.

  Street Fighter III 2nd Impact: Giant Attack arrived on the 30th of September 1997. JoJo's Bizarre Adventure, sold in some markets as JOJO's Venture, came on the 2nd of December 1998. Its Japanese name is JoJo no Kimyō na Bōken.

  The Street Fighter III line closed with 3rd Strike: Fight for the Future on the 12th of May 1999. The final release was JoJo's Bizarre Adventure: Heritage for the Future, on the 13th of September 1999. In all, Capcom developed six games for the board.

  289

• 6. Cracked and Retired

  ›

  After 1999, Capcom stopped manufacturing the hardware. Its next arcade platform was Naomi, which was built on the Dreamcast, so the CP System III became the last proprietary board the company produced.

  On the 31st of March 2015, Capcom ended most technical support for the hardware and its games. The final piece went four years later. Battery replacements stopped on the 28th of February 2019, and with them all official support for the hardware and software.

  By then the lock had already been picked. In June 2007, a researcher named Andreas Naive reverse-engineered the encryption method, which made emulation possible. Later work got around the self-destruct and security routines of individual games. It also produced a so-called super cartridge able to run every CPS-3 game.

  4567