was this device a breakthrough or a flop?
Retrospective reception of the Sega CD is mixed, praising certain games but criticizing its low value for money and limitations on the benefits it provides to the Genesis.
Sega CD

Retrospective reception of the Sega CD is mixed, praising certain games but criticizing its low value for money and limitations on the benefits it provides to the Genesis
what is 'sega cd'? A  CD-ROM accessory for the Mega Drive/Genesis . which company manufactured them? Sega. name a few electronic parts of this product. The CPU is a Motorola 68000 processor,a Backup RAM cartridge, RCA pin jacks, etc. when was this product first time sold in the market? It was released in Japan on December 12, 1991. what are the different models of this product? Two preivious models developed by Sega , and the Genesis CDX,  X'Eye,  Wondermega and others. can any random music cd be played on that device? It can play CD-based games, audio CDs and CD+G discs. what games were generally played on that device? FMV video games.
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Sega CD [SEP] Reception and legacy
Genesis owners that invested in the add-on were sorely disappointed, which undoubtedly helped sour the non-diehards on the brand." In reviewing for "GamePro", Snow commented that "[the] Sega CD marked the first of several Sega systems that saw very poor support; something that devalued the once-popular Sega brand in the eyes of consumers, and something that would ultimately lead to the company's demise as a hardware maker."