was next to impossible. However, in January 2001, the CPS-2 Shock group was able to obtain unencrypted program data by hacking into the hardware, which they distributed as XOR difference tables to produce the unencrypted data from the original ROM images, making emulation possible, as well as restoring cartridges that had been erased because of the suicide system. In January 2007, the encryption method was fully reverse-engineered by Andreas Naive and Nicola Salmoria. It has been determined that the encryption employs two four-round Feistel ciphers with a 64-bit key. The algorithm was thereafter implemented in this state for all known CPS-2 games in MAME. In April 2016, Eduardo Cruz, Artemio Urbina and Ian Court announced the successful reverse engineering of Capcom's CP System II security programming, enabling the clean "de-suicide" and restoration of any dead games without hardware modifications. Region colors Technical specifications CPU: Primary: Capcom DL-1525 (encrypted 68000) @ 16 MHz Sound: Kabuki DL-030P (encrypted Z80, but encryption not used) or standard Z80 @ 8 MHz Capcom custom chipset: GPU: CPS-A & CPS-B Graphics Processors @ 16 MHz (same as CPS-1) Sound chip: Lucent DL-1425 Q1 QSound DSP16A Processor @ 4 MHz DRAM Refresh Controller: DL-2227 I/O Controller: DL-1123 Display: Active resolution: 384×224 pixels Overscan resolution: 512×262 (262 scanlines) Sprites: 900 on screen Colors: Depth: 32-bit (RGBA) Palette: 16,777,216 colors (24-bit) Alpha transparency: 256 levels (8-bit) Colors on screen: 4096 (12-bit) Colors per tile: 16 (4-bit) RAM: 1328 KB (1 MB FPM DRAM, 304 KB SRAM) A-Board: 1 MB FPM DRAM, 280 KB SRAM (256 KB video, 16 KB I/O, 8 KB sound) B-Board: 16 KB SRAM (2× 8 KB) Communication Board: 8 KB SRAM Maximum ROM capacity: 322 Mbit (40.25 MB) Dimensions (A+B board pair): 40 x 27 x 8 cm List of games (42 games) See also CP System CP System III References External links Technical information in the MAME CPS-2 driver CPS-2 Shock - Technical Information CPS-2 at System 16 - The Arcade Museum CPS-2 Keystone Suicide Battery Retainer Mod - JAMMAPARTS.COM CPS-1, CPS-2 and CPS-3 releases comparison Capcom arcade system boards 68k-based arcade system boards de:Capcom Play System