The CP System II or CPS2 is an arcade system board that Capcom first used in 1993 for Super Street Fighter II. It was the successor to their previous CP System and Capcom Power System Changer arcade hardware and was succeeded by the CP System III hardware in 1996, of which the CPS2 would outlive by over four years. The arcade system had new releases for it until the end of 2003. More info here.