SNK Patents
US Patent [[1]] filed in february 1996 by Yoshihiko Hasegawa and Takashi Yamatani describes the NeoGeo's video hardware, VRAM layout and methods for creating sprite effects with the scaling functions.
US Patent [[2]] filed in april 1995 by Yoshihiko Hasegawa describes the MVS BIOS functions, like game-specific parameters, play time stats and time keeping.