The Mega-CD (メガCD) is an add-on device for the Mega Drive video game console, designed and produced by Sega and released in Europe, Australia, New Zealand, Japan, and North America. In North America, it was renamed Sega CD, as the name Mega-CD bore no obvious associative meaning in that market where the console was named "Genesis" instead of "Mega Drive". The device adds a CD-ROM drive to the Mega Drive, allowing the user to play CD-based games and providing additional hardware functionality. In addition, the add-on can also play audio CDs and CD+G discs.
Well Emulated
Because the Sega CD is primarily an expansion for the Sega Genesis, many Genesis emulators natively support Sega CD games already.