The Sega CD, known as Mega-CD in most regions outside North America and Brazil, is a CD-ROM peripheral and format for the Sega Genesis produced by Sega as part of the fourth generation of video game consoles. Originally released in Japan on December 12, 1991, it came to North America on October 15, 1992, and the rest of the world in 1993. The Sega CD plays CD-based games and adds hardware functionality such as a faster CPU and a custom graphics chip for enhanced sprite scaling and rotation. It can also play audio CDs and CD+G discs.