in 1986 in both the US and Japan, but did not gain traction to compete. Similarly, Atari's attempts to compete with the NES via the Atari 7800 in 1987 failed to knock the NES from its dominant position. The NES remained in production until 2003, when it was discontinued along with its successor, the Super Nintendo Entertainment System. Fourth generation (1987–2004) The fourth generation of consoles, also known as the "16-bit generation", further advanced core console technology with 16-bit processors, improving the available graphics and audio capabilities of games. NEC's TurboGrafx-16 (or PC Engine as released in Japan), first released in 1987, is considered the first fourth generation console even though it still had an 8-bit CPU. The console's 16-bit graphics processor gave it capabilities comparable to the other fourth generation systems, and NEC's marketing had pushed the console being an advancement over the NES as a "16-bit" system. Both Sega and Nintendo entered the fourth generation with true 16-bit systems in the 1988 Sega Genesis (Mega Drive in Japan) and the 1990 Super Nintendo Entertainment System (SNES, Super Famicom in Japan). SNK also entered the competition with a modified version of their Neo Geo MVS arcade system into the Neo Geo, released in 1990, which attempted to bridge the gap between arcade and home console systems with the shared use of common game cartridges and memory cards. This generation was notable for the so-called "console wars" between Nintendo and Sega primarily in North America. Sega, to try to challenge Nintendo's dominant position, created the mascot character Sonic the Hedgehog, who exhibited cool personality to appeal to the Western youth in contrast to Nintendo's Mario, and bundled the Genesis with the game of the same name. The strategy succeeded with Sega becoming the dominant player in North America until the mid-1990s. During this generation, the technology costs of using optical discs in the form of CD-ROMs has dropped sufficiently to make them desirable to be used for shipping computer software, including for video games for personal computers. CD-ROMs offered more storage space than game cartridges and could allow for full-motion video and other detailed audio-video works to be used in games. Console manufacturers adapted by created hardware add-ons to their consoles that could read and play CD-ROMs, including NEC's TurboGrafx-CD add-on (as well as the integrated TurboDuo system) in 1988, and the Sega CD add-on for the Genesis in 1991,