Short answers, pulled from the story.
Capcom introduced the CP System II arcade board in 1993 to combat rampant software piracy. The system was designed with a self-destruct feature that turned functional hardware into digital tombstones after a finite period. This security measure embedded a battery-backed memory chip on the B board to store decryption keys essential for running any game.
The CP System II suicide battery stored decryption keys on the B board that were essential for running any game. As the battery drained, the keys vanished and the board refused to execute code, rendering the machine useless even if the physical components remained intact. This phenomenon meant that a legally purchased arcade cabinet could stop working entirely within a few years.
The encryption on the CP System II was cracked in January 2001 when the CPS-2 Shock group hacked into the hardware. They extracted unencrypted data and distributed XOR difference tables that allowed emulation and restoration of dead cartridges. By 2007, Andreas Naive and Nicola Salmoria fully reverse-engineered the encryption to enable MAME drivers.
Japan used green plastic cases with white text, while the U.S.A. used blue plastic with red text. Europe and other regions used blue plastic with blue text, Asia used grey plastic with yellow text, the Hispanic region used orange plastic with green text, Brazil used orange plastic with magenta text, and Oceania used blue plastic with orange text. Rental cabinets were marked with yellow plastic and all-in-one versions used black metal cases.
Super Street Fighter II: The New Challengers was the first game to use the CP System II arcade board. It was released on the 9th of September 1993 and marked the beginning of the system's legacy. The final game, Hyper Street Fighter II: The Anniversary Edition, was released on the 22nd of December 2003.
Eduardo Cruz, Artemio Urbina, and Ian Court announced the successful reverse engineering of Capcom's CP System II security programming in 2016. This breakthrough enabled the clean de-suicide and restoration of any dead games without hardware modifications. The movement allowed preservationists to restore any dead game without modifying the original hardware.