 The Sega CD , released as the Mega @-@ CD ( Japanese : メガCD , Hepburn : Mega @-@ Shī Dī ) in most regions outside North America and Brazil , is a CD @-@ ROM accessory for the Sega Genesis video game console designed and produced by Sega as part of the fourth generation of video game consoles . The add @-@ on was released on December 12 , 1991 in Japan , October 15 , 1992 in North America , and 1993 in Europe . The Sega CD lets the user play CD @-@ based games and adds extra hardware functionality , such as a faster central processing unit and graphic enhancements . It can also play audio CDs and CD + G discs . 
