CP System III

The CP System III (CPシステムIII) or CPS-3 is an arcade system board that was first used by Capcom in 1996 with the arcade game Red Earth. It was the second successor to the CP System arcade hardware, following the CP System II. Like its forerunners, games can be exchanged without altering the core hardware. On the CPS-3, this is accomplished by providing the necessary CD and game-specific security cartridges, which are then loaded into memory. It would be the last proprietary system board Capcom would produce before moving on to the Dreamcast-based Naomi platform.

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 SH-2 CPU with integrated decryption logic, with the per-game key stored in battery-backed SRAM. Capcom chose the CD medium in order to keep down the price of the system. The CP System III also supports displaying games in widescreen resolutions, making it the first and only proprietary system board made by Capcom to support this feature. Street Fighter III: 2nd Impact was the only game out of the entire CP System III library to make use of this feature.

When the CP System III board is first powered on, the contents of the CD are loaded into a bank of Flash ROM SIMMs 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 battery inside the security cartridge dies, or if the cartridge has been tampered with as mentioned earlier. 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, making it the few, if not the only CPS-3 games prevalent after support was dropped, due to its immunity to cartridge suicide or tampering.

In June 2007, the encryption method was reverse-engineered by Andreas Naive, making emulation possible. Later developments led to 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.

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. Battery replacements ended on February 28, 2019, ending all official support of the CP System III hardware and software.

Specifications

 * Main CPU: Hitachi HD6417099 (SH-2) at 25 MHz
 * RAM:
 * 512 KB Work RAM
 * 512 KB Sprite RAM
 * 8 MB Character RAM
 * 256 KB Color RAM
 * 32 KB SS RAM
 * Storage:
 * SCSI CD-ROM drive
 * Flash ROM: Variable amount, up to 8 × 16 MB
 * Sound chip: 16-channel 8-bit sample player, stereo
 * Maximum color palette: 16 million shades
 * Maximum number of colors on screen: 32,768 (15-bit colour, 555 RGB)
 * Palette size: 131,072 pens
 * Colors per tile (backgrounds / sprites): 64 (6 bits per pixel) or 256 (8 bits per pixel), selectable
 * Colors per tile (text overlay): 16 (4 bits per pixel)
 * Maximum number of objects: 1024, with hardware scaling
 * Scroll faces: 4 regular + 1 text overlay 'score screen' layer
 * Scroll features: Horizontal & vertical scrolling, linescroll, linezoom
 * Framebuffer zooming
 * Color blending effects
 * Hardware RLE decompression of 6 bpp and 8 bpp graphics through DMA
 * Resolution, pixels: 384×224 (standard mode) / 496×224 (widescreen mode)

List of games
All six games are developed by Capcom and are all head-to-head fighting games.