CPS-2

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Capcom Play System 2 or CPS-2, is an arcade system board that debuted in 1993 with the game Super Street Fighter 2. The CPS-2 consists of 2 separate parts; the A board, which connects to the JAMMA harness and contains components common between all CPS-2 games, and the B board, which contains the game itself. The relationship between the A and B board is basically the same as that between a home video game console and cartridge. CPS-2 A and B boards are color-coded by region, and each board can only be used with its same-colored mate. The exception to this is that the blue and green boards can be used together.

The B boards hold battery-backed memory containing decryption keys needed for the games to run. As time passes, these batteries lose their charge and the games stop functioning. This is known to hobbyists as the "suicide battery". It is possible to bypass the original battery and swap it out with a new one in-circuit, but this must be done before the original falls below 2V or the keys will be lost.

Due to the heavy encryption, it was believed for a long time that CPS-2 emulation was next to impossible. However, in January 2001, the CPS-2 Shock group was able to obtain unencrypted program data by hacking the hardware and provided XOR difference tables to produce this data from ROM images, making emulation possible. The legality of these difference tables is disputed.

In January 2007, the encryption method was fully reverse-engineered by Andreas Naive and Nicola Salmoria. It has been determined, with 99.9% confidence, that the encryption employs two four-round Feistel networks with a 64-bit key.[1][2] The algorithm was thereafter implemented in this state for all known CPS-2 games in MAME.

Also thanks to the encryption, the system was never bootlegged until unencrypted program data became available.

1 CPS-2 Region Colors
2 CPS-2 Specifications
3 List of CPS-2 Games
4 See also
5 External links

[edit] CPS-2 Region Colors

Blue: U.S.A., Canada, and Europe
Green: Japan
Orange: South America
Gray: Asia
Yellow: "Region 0" (available by rental only)
Black: "Region 0" incorporated A and B board in the same unit

[edit] CPS-2 Specifications

Main CPU: Motorola 68000 @ 16 MHz
Sound CPU: ZiLOG Z80 @ 8 MHz
Sound Chips: Q-Sound @ 4 MHz
Color Palette: 32 bit
Total On Screen Colors: 4096
Colors per Tile: 16 (4 bits per pixel)
Object Number : 900 (16 x 16 pixels)
Scroll Faces : 3
Resolution : 384 x 224

[edit] List of CPS-2 Games

It has been suggested that this article or section be merged into List of cps-2 games. (Discuss)

The Japanese title is given first, with the US, EU and World titles given second (unless stated otherwise). Years shown are for original release of each game. Full list of cps-2 games