when was this product first time sold in the market?
It was released in Japan on December 12, 1991.
Sega CD
It was released in Japan on December 12, 1991
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.
wiki:19607341
Sega CD [SEP] Launch
Sega announced the release of the Mega-CD in Japan for late 1991, and North America (as the Sega CD) in 1992. It was unveiled to the public for the first time at the 1991 Tokyo Toy Show, to positive reception from critics. It was released in Japan on December 12, 1991, initially retailing at JP¥49,800. Though the unit sold quickly, the small install base of the Mega Drive in Japan meant that sales declined rapidly. Within its first year in Japan, the Mega-CD only sold 100,000 units. Third-party development of games for the new system suffered because Sega took a long amount of time to release software development kits.