Editing Sega CD

{{Short description|Video game console add-on}}
{{featured article}}
{{Use mdy dates|date=December 2021}}
{{Infobox information appliance
| title = Sega CD / Mega-CD
| logo = [[File:Sega CD Logo.svg|250px|North American logo]] 
[[File:MEGA-CD logo.png|150px|Japanese logo]]
| image = <div style="white-space: nowrap; border: #dadada solid 1px;">[[File:Sega-CD-Model1-Set.jpg|frameless|250px|Original North American Sega CD and a model 1 Sega Genesis]]{{pb}}[[File:Sega-CD-Model2-Set.jpg|frameless|250px|North American model 2 Sega CD and a model 2 Sega Genesis]]</div>
| caption = '''Top:''' Original Sega CD {{small|(bottom)}} attached to a Model 1 Genesis.{{pb}}'''Bottom:''' Model 2 Sega CD {{small|(on right)}} attached to a Model 2 Genesis.
| aka = Mega-CD (most regions outside North America and Brazil)
| developer = [[Sega]]
| manufacturer = Sega
| type = [[Video game console]] [[Video game accessory|add-on]]
| generation = [[Fourth generation of video game consoles|Fourth]]
| releasedate = {{Video game release|JP|December 12, 1991|NA|October 15, 1992|AU|March 1993|UK|April 2, 1993|EU|April 1993|BR|October 1993}}
| lifespan = 1991–1996
| price = {{ubl|[[JP¥]]49,800|[[US$]]299|[[Pound sterling|£]]270}}
| discontinued = January 1, 1996
| unitssold = 2.24 million
| media = [[CD-ROM]], [[CD+G]]
| cpu = [[Motorola 68000]]
| CPUspeed = 12.5&nbsp;MHz
| storage = 6.5&nbsp;Mbit [[RAM]] (programs, pictures, and sounds), 128&nbsp;[[Kilobit|kbit]] RAM (CD-ROM cache), 64&nbsp;kbit RAM (backup memory)
| sound = [[Ricoh]] RF5C164
| topgame = ''[[Sonic CD]]'', 1.5 million<ref>{{cite book|title=Guinness World Records 2016: Gamer's Edition|url=https://archive.org/details/guinnessworldrec0000guin_y5t0|url-access=registration|date=2015|isbn=9781910561096|publisher=[[Jim Pattison Group]]}}</ref>
| related = [[32X]]
| graphics = custom ASIC
}}

The '''Sega CD''', known as {{nihongo foot|'''Mega-CD'''|メガ{{ruby|CD|シーディー}}|Mega Shī Dī|lead=yes|group=lower-alpha}}<!-- See [[WP:JFN]] --> in most regions outside North America and Brazil, is a [[CD-ROM]] accessory and format for the [[Sega Genesis]] produced by [[Sega]] as part of the [[fourth generation of video game consoles]]. Originally released in November 1991, it came to North America in late 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 (computer graphics)|sprite]] scaling and rotation. It can also play [[Compact Disc Digital Audio|audio CDs]] and [[CD+G]] discs.

Sega sought to match the capabilities of the competing [[TurboGrafx-16#TurboGrafx-CD/CD-ROM²|PC Engine CD-ROM² System]], and partnered with [[JVC]] to design the Sega CD. Sega refused to consult with their American division until the project was complete, fearful of leaks. The Sega CD was redesigned several times by Sega and was also licensed to third parties, including [[Pioneer Corporation|Pioneer]] and [[Aiwa]] who released [[home audio]] products with Sega CD gaming capability. The main benefit of CD technology at the time was greater [[Computer data storage|storage]]; CDs offered approximately 160 times more space than Genesis/Mega Drive [[ROM cartridge|cartridges]]. This benefit manifested as [[full-motion video]] (FMV) games such as the [[1993 Congressional hearings on video games|controversial]] ''[[Night Trap]]''.

The Sega CD [[List of Sega CD games|game library]]<ref name=":3">{{Cite web |title=Sega-CD/Mega-CD video games list, 'a' to 'm' |url=https://www.uvlist.net/platforms/games-list/89 |access-date=2023-01-03 |website=Universal Videogame List |language=en}}</ref> features acclaimed games such as ''[[Sonic CD]]'', ''[[Lunar: The Silver Star]]'', ''[[Lunar: Eternal Blue]]'', ''[[Popful Mail]]'', and ''[[Snatcher (video game)|Snatcher]]'', but also many Genesis [[Port (video gaming)|ports]] and poorly received [[FMV game]]s. Only 2.24 million Sega CD units were sold, after which Sega discontinued it to focus on the [[Sega Saturn]]. Retrospective reception has been mixed, with praise for some games and functions, but criticism for its lack of deep games and its high price. Sega's poor support for the Sega CD has been criticized as the beginning of the devaluation of its brand.

==History==
===Background===
Released in 1988, the [[Sega Genesis|Genesis]] (known as the Mega Drive in most territories outside of North America) was Sega's entry into the [[Fourth generation of video game consoles|fourth generation]] of video game consoles.<ref name="Retroinspection"/> In the early 1990s, Sega of America CEO [[Tom Kalinske]] helped make the Genesis a success by cutting the price, developing games for the American market with a new American team, continuing aggressive advertising campaigns, and selling ''[[Sonic the Hedgehog (1991 video game)|Sonic the Hedgehog]]'' with the Genesis as a [[pack-in game]].<ref name="Kent_pp424_431">{{cite book|last=Kent|first=Steven L.|title=[[The Ultimate History of Video Games: The Story Behind the Craze that Touched our Lives and Changed the World]]|publisher=[[Prima Publishing]]|year=2001|isbn=0-7615-3643-4|location=Roseville, California|pages=421–438|chapter=|author-link=Steven L. Kent}}</ref>

By the early 1990s, [[compact disc]]s (CDs) were making headway as a [[storage medium]] for music and video games. [[NEC]] had been the first to use CD technology in a video game console with their [[TurboGrafx-16#TurboGrafx-CD/CD-ROM²|PC Engine CD-ROM² System]] add-on in October 1988 in Japan (launched in North America as the TurboGrafx-CD the following year), which sold 80,000 units in six months.<ref name="Sentinel">{{cite news|last=Takiff|first=Jonathan|date=April 29, 1989|title=CD+G to be Unveiled in May|newspaper=[[Orlando Sentinel]]|url=http://docs.newsbank.com/openurl?ctx_ver=z39.88-2004&rft_id=info:sid/iw.newsbank.com:AWNB:ORLB&rft_val_format=info:ofi/fmt:kev:mtx:ctx&rft_dat=0EB760D7A3006527&svc_dat=InfoWeb:aggregated5&req_dat=0ECC86DE7A4704AD|url-status=live|url-access=subscription|access-date=December 21, 2013|archive-url=https://web.archive.org/web/20131110080330/http://docs.newsbank.com/openurl?ctx_ver=z39.88-2004|archive-date=November 10, 2013|via=[[NewsBank]]}}</ref> That year, Nintendo announced a partnership with [[Sony]] to develop a [[Super NES CD-ROM|CD-ROM peripheral]] for the [[Super Nintendo Entertainment System]] (SNES). [[Commodore International]] released their CD-based [[CDTV]] multimedia system in early 1991, while the [[CD-i]] from [[Philips]] arrived later that year.<ref name="segacd"/> According to Nick Thorpe of ''[[Retro Gamer]]'', Sega would have received criticism from investors and observers had it not developed a [[CD-ROM]] game system.<ref name=":0">{{Cite magazine|last=Thorpe|first=Nick|date=April 2016|title=Sega's Big Gamble|magazine=[[Retro Gamer]]|issue=153|pages=20–29}}</ref>

=== Development ===
Shortly after the release of the Genesis, Sega's Consumer Products Research and Development Labs, led by manager Tomio Takami, were tasked with creating a CD-ROM add-on. It was originally intended to equal the capabilities of the TurboGrafx-CD, but with twice as much [[random-access memory]] (RAM).<ref name="Takami">{{cite magazine|title=Behind the Screens at Sega of Japan|magazine=[[Electronic Gaming Monthly]]|issue=29|volume=3|date=December 1991|pages=115, 122}}</ref> In addition to relatively short loading times, Takami's team planned to implement [[2.5D|hardware]] [[scaling (geometry)|scaling]] and [[rotation]] similar to that of [[List of Sega arcade system boards|Sega's arcade games]], which required a dedicated [[digital signal processor]].<ref name="Takami"/><ref name="Siliconera">{{cite web|author=Sato|date=September 18, 2013|title=Sega's Original Hardware Developer Talks About The Company's Past Consoles|url=http://www.siliconera.com/2013/09/18/segas-original-hardware-developer-talks-about-the-companys-past-consoles/|url-status=dead|archive-url=https://web.archive.org/web/20131202230217/http://www.siliconera.com/2013/09/18/segas-original-hardware-developer-talks-about-the-companys-past-consoles/|archive-date=December 2, 2013|access-date=December 21, 2013|website=[[Siliconera]]}}</ref> A custom graphics chip would implement these features, alongside an additional [[sound chip]] manufactured by [[Ricoh]].<ref name=":0" /> According to Kalinske, Sega was ambitious about what CD-ROM technology would do for video games, with its potential for "movie graphics", "rock and roll concert sound" and 3D animation.<ref name=":0" /> 

However, two major changes were made towards the end of development that dramatically raised the price of the add-on. Because the Genesis' [[Motorola 68000]] CPU was too slow to handle the Sega CD's new graphical capabilities, an additional 68000 CPU was incorporated.<ref name="Takami" /> This second CPU has a [[clock speed]] of 12.5&nbsp;MHz, faster than the 7.67&nbsp;MHz CPU in the Genesis.<ref name=":0" /> Responding to rumors that NEC planned a memory upgrade to bring the TurboGrafx-CD RAM from 0.5&nbsp;[[Mbit]] to between 2 and 4&nbsp;Mbit, Sega increased the Sega CD's available RAM from 1 to 6.5&nbsp;Mbit.<ref name="Takami" /> This proved to be a technical challenge, since the Sega CD's RAM access speed was initially too slow to run programs effectively, and the developers had to focus on increasing the speed.<ref name="Siliconera" /> The estimated cost of the device rose to US$370, but market research convinced Sega executives that consumers would be willing to pay more for a state-of-the-art machine.<ref name="Takami" /> Sega partnered with [[JVC]], which had been working with [[Warner Communications|Warner New Media]] to develop a CD player under the [[CD+G]] standard.<ref name="Sentinel" /><ref name="economist">{{cite news |title=Sega v Nintendo: Sonic Boom |newspaper=[[The Economist]] |date=January 25, 1992 |id={{ProQuest|224134880}} {{subscription required}}}}</ref>

Sega of America was not informed of the project details until mid-1991. Despite being provided with preliminary technical documents earlier in the year, the American division was not given a functioning unit to test.<ref>{{cite web|last=Horowitz |first=Ken |url=http://www.sega-16.com/2012/03/interview-scot-bayless/ |title=Interview:Scot Bayless |work=Sega-16 |date=March 1, 2012 |access-date=November 11, 2015 |url-status=live |archive-url=https://web.archive.org/web/20120303233609/http://www.sega-16.com/2012/03/interview-scot-bayless/ |archive-date=March 3, 2012}}</ref> According to former executive producer Michael Latham: "When you work at a multinational company, there are things that go well and there are things that don't. They didn't want to send us working Sega CD units. They wanted to send us dummies and not send us the working CD units until the last minute because they were concerned about what we would do with it and if it would leak out. It was very frustrating."<ref name="segacd">{{cite book|last=Kent|first=Steven L.|title=The Ultimate History of Video Games: The Story Behind the Craze that Touched our Lives and Changed the World|publisher=Prima Publishing|year=2001|isbn=0-7615-3643-4|location=Roseville, California|pages=439–460}}</ref> 

Latham and Sega of America vice president of licensing Shinobu Toyoda assembled a functioning Sega CD by acquiring a ROM for the system and installing it in a dummy unit.<ref name="segacd" /> The American staff were frustrated by the Sega CD's construction. Former senior producer Scot Bayless said: "[It] was designed with a cheap, consumer-grade audio CD drive, not a CD-ROM. Quite late in the run-up to launch, the quality assurance teams started running into severe problems with many of the units—and when I say severe, I mean units literally bursting into flames. We worked around the clock, trying to catch the failure in-progress, and after about a week we finally realized what was happening." He said the problems were caused by certain games excessively seeking to different tracks on the disc (as opposed to continuously playing / streaming), leading to overheating of the motors which repositioned the laser head assembly.<ref name="Eurogamer">{{cite web|author=McFerran, Damien|title=The Rise and Fall of Sega Enterprises|year=2012|website=[[Eurogamer]]|url=http://www.eurogamer.net/articles/2012-02-22-the-rise-and-fall-of-sega-enterprises|access-date=July 25, 2013|url-status=live|archive-url=https://web.archive.org/web/20140216124431/http://www.eurogamer.net/articles/2012-02-22-the-rise-and-fall-of-sega-enterprises|archive-date=February 16, 2014}}</ref>

===Launch===
As early as 1990, magazines were covering a CD-ROM expansion for the Genesis.<ref>{{Cite magazine|date=November 1990|title=Big in Japan|magazine=[[Raze (magazine)|Raze]]|issue=1|pages=20–21}}</ref><ref>{{Cite magazine|date=September 1990|title=CD-ROM|magazine=[[Beep! Mega Drive]]|language=Japanese|page=20}}</ref> 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 at the 1991 Tokyo Toy Show,<ref name="RetroGamer"/><ref>{{Cite magazine|date=August 1991|title=Sega of Japan Unveils Mega-CD at Tokyo Toy Show!|magazine=[[Electronic Gaming Monthly]]|issue=25|page=36}}</ref> to positive reception from critics,<ref name="RetroGamer" /> and at the [[Consumer Electronic Show]] in [[Chicago]] in mid-1991.<ref>{{Cite magazine|date=June 22, 1991|title=Does the CD Console War Start Here?|magazine=[[New Computer Express]]|issue=137|page=4}}</ref>  It was released in Japan on December 12, 1991, initially retailing at [[JP¥]]49,800.<ref>{{cite web|title=Mega-CD|publisher=[[Sega Corporation]]|language=ja|access-date=March 29, 2014|url=http://sega.jp/fb/segahard/mcd/|url-status=live|archive-url=https://web.archive.org/web/20140716110215/http://sega.jp/fb/segahard/mcd/|archive-date=July 16, 2014}}</ref> Though the Mega-CD sold quickly, the small install base of the Mega Drive in Japan meant that sales declined rapidly.<ref name="RetroinspectionCD">{{cite magazine|author=McFerran|first=Damien|date=February 2009|title=Retroinspection: Mega-CD|magazine=[[Retro Gamer]]|issue=61|pages=82–87}}</ref> Within its first three months, the Mega-CD sold 200,000 units, but only sold an additional 200,000 over the next three years.<ref name=":0" /> Third-party game development suffered because Sega took a long time to release [[software development kit]]s.<ref name="RetroGamer" /><ref name="AllgameCD"/> Other factors affecting sales included the high launch price of the Mega-CD in Japan and only two games available at launch,<ref name="RetroGamer" /> with only five published by Sega within the first year.<ref name=":0" />

[[File:Sega-Genesis-CD-Model-1-Bare-wPlate.jpg|thumb|A model 1 Sega CD without a Genesis attached. The steel joining plate was included to act as RF shielding between the CD and console hardware.]]On October 15, 1992, the Mega-CD was released in North America as the Sega CD, with a retail price of [[US$]]299.<ref name="segacd" /> Advertising included one of Sega's slogans, "Welcome to the Next Level". Though only 50,000 units were available at launch due to production problems, the Sega CD sold over 200,000 units by the end of 1992<ref name="RetroinspectionCD" /> and 300,000 by July 1993.<ref>{{cite news|first=Andrew|last=Pollack|url=https://www.newspapers.com/image/273694979/| archive-url=https://ghostarchive.org/archive/20211019/https://www.newspapers.com/image/273694979/| archive-date=October 19, 2021|title=Sega strives to be a Disney for the new electronic age|date=July 8, 1993|agency=The New York Times|newspaper=Honolulu Star-Bulletin|access-date=December 29, 2020|url-status=live|page=D4|via=Newspapers.com}}{{cbignore}}</ref> As part of Sega's sales, [[Blockbuster (retailer)|Blockbuster]] purchased Sega CD units for rental in their stores.<ref name="SunSentinel">{{cite news|author=McCash, Vicki|title=Sega Channel To Offer Games Via Cable TV|url=http://articles.sun-sentinel.com/1993-04-28/business/9302080600_1_sega-channel-sega-cd-sega-genesis|date=April 28, 1993|access-date=December 9, 2013|newspaper=[[Sun-Sentinel|Broward and Palm Beach Sun Sentinel]]|url-status=dead|archive-url=https://web.archive.org/web/20131213040029/http://articles.sun-sentinel.com/1993-04-28/business/9302080600_1_sega-channel-sega-cd-sega-genesis|archive-date=December 13, 2013}}</ref>  Sega of America emphasized that the Sega CD's additional storage space allowed for [[full-motion video]] (FMV),<ref name="AllgameCD" /><ref name="CDFollies">{{cite web|last=Buchanan|first=Levi|title=Sega CD Follies|website=[[IGN]]|date=October 15, 2008|access-date=July 1, 2013|url=http://www.ign.com/articles/2008/10/15/sega-cd-follies|url-status=live|archive-url=https://web.archive.org/web/20130828085544/http://www.ign.com/articles/2008/10/15/sega-cd-follies|archive-date=August 28, 2013}}</ref><ref name="1UP">{{cite web|author=Parish, Jeremy |title=20 Years Ago, Sega Gave Us the Sega CD |website=[[1UP.com]] |date=October 16, 2012 |access-date=December 11, 2016 |url=http://www.1up.com/features/sega-cd-anniversary |url-status=dead |archive-url=https://archive.today/20130615202428/http://www.1up.com/features/sega-cd-anniversary |archive-date=June 15, 2013 }}</ref> with [[Digital Pictures]] becoming an important partner.<ref name="segacd" /> After the initial competition between Sega and Nintendo to develop a CD-based add-on, [[Nintendo]] canceled development of a CD add-on for the SNES after having partnered with Sony and then Philips to develop one.<ref name="segacd" />

The Mega-CD was launched in Europe in April 1993,<ref name=":0" /><ref name="RetroGamer" /> starting with the United Kingdom on April 2, 1993, at a price of £269.99. The European version was packaged with ''[[Sol-Feace]]'' and ''[[Cobra Command (1984 video game)|Cobra Command]]'' in a two-disc set, along with a [[Sega Classics Arcade Collection|compilation CD]] of five Mega Drive games.<ref name="CVG 138">{{cite magazine|date=May 1993|title=News: Mega CD Launches!|magazine=[[Computer and Video Games]]|location=United Kingdom|issue=138|page=8}}</ref> Only 70,000 units were initially available in the UK, but 60,000 units were sold by August 1993.<ref name="RetroinspectionCD" /> The Mega-CD was released in Australia in March 1993.<ref>{{Cite magazine|date=April 1993|title=Disc is it: Mega-CD|magazine=Megazone|issue=27|pages=20–21}}</ref>  Brazilian toy company [[Tectoy]] released the Sega CD in Brazil in October 1993, retaining the North American name despite the use of the name Mega Drive for the base console there.<ref>{{Cite magazine|date=October 1993|title=Bits: Sega CD|magazine=VideoGame|language=Portuguese|volume=3|issue=31|pages=6–7}}</ref><ref name=":1">{{Cite magazine|last=Szczepaniak|first=John|date=November 2006|title=Company Profile: Tec Toy|magazine=[[Retro Gamer]]|publisher=|issue=30|pages=50–53|issn=}}</ref>

Sega released a second model, the Sega CD 2 (Mega-CD 2), on April 23, 1993, in Japan.<ref name="Megacd2">{{cite web|title=Mega-CD 2|url=http://sega.jp/fb/segahard/mcd/mcd2.html|publisher=Sega Corporation|language=ja|access-date=March 29, 2014|url-status=live|archive-url=https://web.archive.org/web/20140530063620/http://sega.jp/fb/segahard/mcd/mcd2.html|archive-date=May 30, 2014}}</ref> It was released in North America several months later at a price of [[US$]]229, bundled with one of the bestselling Sega CD games, ''[[Sewer Shark]]''.<ref name="AllgameCD" /><ref>{{cite magazine|title=Sega Packs Sewer Shark with New Sega CD|magazine=[[GamePro]]|issue=52|date=November 1993|page=261}}</ref> Designed to bring down the manufacturing costs of the Sega CD, the newer model is smaller and does not use a motorized disc tray.<ref name="RetroinspectionCD"/> A limited number of games were developed that used the Sega CD and another Genesis add-on, the [[32X]], released in November 1994.<ref name="AllgameCD32X">{{cite web|last=Marriott|first=Scott Alan|title=Sega Genesis 32X CD&nbsp;– Overview|website=[[Allgame]]|access-date=July 2, 2013|url=http://allgame.com/platform.php?id=43|url-status=dead|archive-url=https://web.archive.org/web/20141210111102/http://www.allgame.com/platform.php?id=43|archive-date=December 10, 2014}}</ref>

===''Night Trap'' controversy===
{{see also|1993 congressional hearings on video games}}
On December 9, 1993, the [[United States Congress]] began hearings on video game violence and the marketing of violent video games to children.<ref name="night trap">{{cite book|last=Kent|first=Steven L.|title=The Ultimate History of Video Games: The Story Behind the Craze that Touched our Lives and Changed the World|publisher=Prima Publishing|year=2001|isbn=0-7615-3643-4|location=Roseville, California|pages=461–480|chapter=}}</ref> The Sega CD game ''[[Night Trap]]'', an FMV adventure game by Digital Pictures, was at the center of debate.<ref name="1UP" /> ''Night Trap'' had been brought to the attention of United States Senator [[Joe Lieberman]], who said: "It ends with this attack scene on this woman in lingerie, in her bathroom. I know that the creator of the game said it was all meant to be a satire of ''[[Dracula]]''; nonetheless, I thought it sent out the wrong message." Lieberman's research concluded that the average video game player was between seven and twelve years old, and that video game publishers were marketing violence to children.<ref name="night trap" />

In the United Kingdom, ''Night Trap'' was discussed in [[Parliament of the United Kingdom|Parliament]].<ref name="Eurogamer" /> Former Sega Europe development director Mike Brogan noted that ''Night Trap'' brought Sega publicity, and helped reinforce Sega's image as an "edgy company with attitude".<ref name="Eurogamer" /> Despite the increased sales, Sega recalled ''Night Trap'' and rereleased it with revisions in 1994.<ref>{{cite news|last=Burgess|first=John|title=Sega to Withdraw, Revise "Night Trap"|date=January 11, 1994|newspaper=[[The Washington Post]]}}</ref> Following the congressional hearings, video game manufacturers came together in 1994 to establish a unified rating system, the [[Entertainment Software Rating Board]].<ref name="night trap" />

===Decline===
By the end of 1993, sales of the Sega CD had stalled in Japan and were slowing in North America.  In Europe, sales of Mega-CD games were outpaced by games for the [[Amiga CD32]].<ref name=":0" /> Newer CD-based consoles such as the [[3DO Interactive Multiplayer]] rendered the Sega CD technically obsolete, reducing public interest.<ref name="RetroinspectionCD"/> In late 1993, less than a year after the Sega CD had launched in North America and Europe, the media reported that Sega was no longer accepting in-house development proposals for the Mega-CD in Japan.<ref>{{cite magazine|title=Gaming Gossip|magazine=[[Electronic Gaming Monthly]]|issue=53|date=December 1993|page=64}}</ref> By 1994, {{nowrap|1.5 million}} units had been sold in the United States and 415,000 in Western Europe.<ref name="SD">{{cite magazine | magazine=[[Screen Digest]] | title=Finance & Business | date=March 1995 | archive-url=https://archive.today/20211124142424/https://www.scribd.com/doc/208776076/Screen-Digest?secret_password=2ntzw5zfrtsy8kxequmg | archive-date=November 24, 2021 | url-status=live | url=https://www.scribd.com/doc/208776076/Screen-Digest?secret_password=2ntzw5zfrtsy8kxequmg | page=56 | access-date=May 23, 2021 }}</ref> Kalinske blamed the Sega CD's high price for limiting its potential market; Sega attempted to add value in the US and the UK by bundling more games, with some packages including up to five games.<ref name=":0" /> 

In early 1995, Sega shifted its focus to the [[Sega Saturn]] and discontinued advertising for Genesis hardware, including the Sega CD. Sega discontinued the Sega CD in the first quarter of 1996, saying that it needed to concentrate on fewer platforms and that the Sega CD could not compete due to its high price and outdated single-speed drive.<ref>{{cite magazine|last=Sherman |first=Chris |title=Sega Pulls Plug on Sega CD|magazine=[[Next Generation (magazine)|Next Generation]]|issue=15|date=March 1996|page=19}}</ref> According to Thorpe, the Sega CD only reached a more popular price point in 1995, by which time customers were willing to wait for newer consoles.<ref name=":0" /> The last scheduled Sega CD games, ports of ''[[Myst]]'' and ''[[Brain Dead 13]]'',<ref>{{cite magazine|title=Buyers Beware |magazine=[[GamePro]]|issue=89|date=February 1996|page=14}}</ref> were cancelled. 2.24 million Sega CD units were sold worldwide.<ref name=":0" /><ref name="Sega Stats">{{cite magazine|date=June 21, 1996|title=Weekly ''Famitsu'' Express|magazine=[[Famitsu]]|volume=11|issue=392|lang=ja}}</ref>

==Technical specifications==
[[File:Sega-CD-Base-Mk2-Inside-V1-01.jpg|thumb|right|The motherboard and CD laser assembly to a model 2 Sega CD]]
The Sega CD can only be used in conjunction with a Genesis system, attaching through an expansion slot on the side of the main console.<ref>{{Cite magazine|date=February 1993|title=Mega-CD|magazine=[[Computer and Video Games]]|issue=135|page=16}}</ref> It requires its own power supply.<ref name="specs" /> A core feature of the Sega CD is the increase in data storage by its games being CD-ROMs; whereas [[ROM cartridge]]s of the day typically contained 8 to 16 megabits of data, a CD-ROM disc can hold more than 640 [[megabyte]]s of data, more than 320 times the storage of a Genesis cartridge. This increase in storage allows the Sega CD to play [[FMV game]]s.<ref name="segacd" /> In addition to playing its own library of games in CD-ROM format, the Sega CD can also play compact discs and [[karaoke]] CD+G discs, and can be used in conjunction with the 32X to play [[32-bit]] games that use both add-ons. The second model, also known as the Sega CD 2, includes a steel joining plate to be screwed into the bottom of the Genesis and an extension spacer to work with the [[Sega Genesis#Variations|original Genesis model]].<ref name="specs">{{cite book|title=Sega CD instruction manual (model 2)|publisher=Sega of America, Inc.|year=1993}}</ref>

The main [[CPU]] of the Sega CD is a 12.5&nbsp;[[MHz]] [[16-bit]] Motorola 68000 processor,<ref name="RetroGamer">{{cite magazine|author=Birch, Aaron|title=Next Level Gaming: Sega Mega-CD|magazine=[[Retro Gamer]]|issue=17|year=2005|pages=36–42}}</ref><ref>{{cite web|url=http://sega.jp/fb/segahard/mcd/data.html|title=Mega-CD data|publisher=Sega Corporation|language=ja|access-date=March 24, 2014|url-status=live|archive-url=https://web.archive.org/web/20131016142854/http://sega.jp/fb/segahard/mcd/data.html|archive-date=October 16, 2013}}</ref> which runs 5&nbsp;MHz faster than the Genesis processor.<ref name="AllgameCD" /> It contains 1&nbsp;Mbit of [[booting|boot]] [[ROM]], allocated for the CD game [[BIOS]], CD player software, and compatibility with CD+G discs. 6.5&nbsp;Mbit of RAM is allocated to data for programs, pictures, and sounds; 128&nbsp;Kbit to CD-ROM data [[cache memory]]; and an additional 64&nbsp;Kbit is allocated as the backup memory.<ref name="specs" /><ref name=":2">{{Cite magazine|date=September 1993|title=Sega Mega-CD II: Retour vers le futur|magazine=Player One|language=French|issue=34|page=53}}</ref> Additional backup memory in the form of a 1&nbsp;Mbit Backup RAM Cartridge was also available as a separate purchase, released near the end of the system's life.<ref>{{cite magazine|title=Saved by the Cart|magazine=[[GamePro]]|issue=83|date=August 1995|page=108}}</ref><ref>{{cite web|url=https://sega.jp/fb/segahard/mcd/backup.html|language=Japanese|accessdate=December 12, 2021|title=Mega CD RAM|publisher=[[Sega Corporation]]|archive-date=October 20, 2020|archive-url=https://web.archive.org/web/20201020092507/https://sega.jp/fb/segahard/mcd/backup.html|url-status=live}}</ref> The graphics chip is a custom [[ASIC]],<ref name=":2" /> and can perform similarly to the SNES's [[Mode 7]], but with the ability to handle more objects at the same time.<ref name=":0" /> Audio is supplied through the Ricoh RF5C164, and two [[RCA connector|RCA pin jacks]] allow the Sega CD to output stereophonic sound separate from the Genesis. Combining stereo sound from a Genesis to either version of the Sega CD requires a cable between the Genesis's headphone jack and an input jack on the back of the CD unit. This is not required for the second model of the Genesis.<ref name=":0" /><ref name="specs" /> Sega released an additional accessory to be used with the Sega CD for karaoke, including a microphone input and various sound controls.<ref>{{cite web|url=https://sega.jp/fb/segahard/mcd/karaoke.html|language=Japanese|title=Mega CD Karaoke|publisher=[[Sega Corporation]]|accessdate=December 12, 2021|archive-date=November 15, 2020|archive-url=https://web.archive.org/web/20201115021909/https://sega.jp/fb/segahard/mcd/karaoke.html|url-status=live}}</ref>

==Models==
{{see also|Sega Genesis#Variations}}
{| class="wikitable" style="float:right; margin:0.5em 0 0.5em 1.4em;"
|-
|[[File:Sega-CD-Model1-Set.jpg|none|90px]] || [[File:Sega-CD-Model2-Set.jpg|none|90px]] || [[File:Genesis-CDX-Console-Set.jpg|none|90px]]
|-
|width="90"| {{center|Genesis and Sega CD (original models)}} ||width="90"| {{center|Genesis and Sega CD (second models)}} ||width="90"| {{center|Genesis CDX}}
|-
|[[File:Console-wondermega.jpg|none|90px]] || [[File:Victor-WonderMega-RG-M2-Console-Set.jpg|none|90px]] ||[[File:Pioneer-LaserActive-Set-FL.jpg|none|90px]]
|-
|width="90"| {{center|[[JVCKenwood Victor Entertainment|Victor]] Wondermega RG-M1}} ||width="90"| {{center|Victor Wondermega RG-M2}} ||width="90"|{{center|Pioneer LaserActive}}
|}

Several models of the Sega CD were released. The original model used a front-loading motorized disc tray and sat underneath the Genesis. The second model was redesigned to sit next to the Genesis and featured a top-loading disc tray.<ref name="AllgameCD">{{cite web |author=Beuscher, David |title=Sega CD&nbsp;– Overview |website=[[Allgame]] |access-date=June 27, 2013 |url=http://allgame.com/platform.php?id=36 |url-status=dead |archive-url=https://web.archive.org/web/20141114094429/http://www.allgame.com/platform.php?id=36 |archive-date=November 14, 2014 }}</ref> Sega also released the Genesis CDX (Multi-Mega in Europe), a combined Genesis and Sega CD, with additional functionality as a [[portable CD player]].<ref name=":0" /><ref name="AllgameCDX">{{cite web |last=Marriott |first=Scott Alan |title=Sega Genesis CDX&nbsp;– Overview |website=[[Allgame]] |access-date=June 27, 2013 |url=http://allgame.com/platform.php?id=17675 |archive-url=https://web.archive.org/web/20141114094412/http://www.allgame.com/platform.php?id=17675 |archive-date=November 14, 2014 |url-status=dead }}</ref>

Three additional system models were created by other electronics companies. Working with Sega, JVC released the Wondermega, a combination of the Genesis and Sega CD with high-quality audio, on April 1, 1992, in Japan. The Wondermega was redesigned by JVC and released as the X'Eye in North America in September 1994. Its high price kept it out of the hands of average consumers.<ref name=":0" /><ref name="JVC">{{cite web|author=Marriott, Scott Alan|title=JVC X'Eye&nbsp;– Overview|website=[[Allgame]]|access-date=July 2, 2013|url=http://www.allgame.com/platform.php?id=18826|url-status=dead|archive-url=https://web.archive.org/web/20141114094430/http://www.allgame.com/platform.php?id=18826|archive-date=November 14, 2014}}</ref> Another console, the [[LaserActive]] by [[Pioneer Corporation]], can play Genesis and Sega CD games if equipped with the Mega-LD attachment developed by Sega.<ref name=":0" /><ref name="Pioneer" /> The LaserActive was positioned to compete with the 3DO Interactive Multiplayer, but the combined system and Mega-LD pack retailed at too expensive a price for most consumers.<ref name="Pioneer">{{cite web |author=Marriott, Scott Alan |title=Pioneer LaserActive&nbsp;– Overview |website=[[Allgame]] |access-date=July 2, 2013 |url=http://www.allgame.com/platform.php?id=17669 |url-status=dead |archive-url=https://web.archive.org/web/20141114094412/http://www.allgame.com/platform.php?id=17669 |archive-date=November 14, 2014 }}</ref> [[Aiwa]] released the CSD-GM1, a combination Mega Drive and Mega CD unit built into a [[boombox]].<ref name="Retroinspection">{{cite magazine|magazine=[[Retro Gamer]]|title=Retroinspection: Mega Drive|author=Sczepaniak, John|issue=27|year=2006|pages=42–47}}</ref> The CSD-GM1 was released in Japan in 1994.<ref name=":0" />

==Games==
{{See also|List of Sega CD games}}
[[Image:SonicCD.PNG|thumb|right|''Sonic CD''{{'}}s special stage uses the Sega CD's enhanced graphical capabilities.]]
The Sega CD supports a library of more than 200 games created by Sega and third-party publishers.<ref name=":3" /> Six Sega CD games were also released in versions that used both the Sega CD and 32X add-ons.<ref name="AllgameCD32X" /> 

Well regarded Sega CD games include ''[[Sonic CD]]'', ''[[Lunar: The Silver Star]]'', ''[[Lunar: Eternal Blue]]'', ''[[Popful Mail]]'', and ''[[Snatcher (video game)|Snatcher]]'', as well as the controversial ''Night Trap''.<ref name="CDFollies" /><ref name="1UP" /><ref>{{cite web|last=Parish|first=Jeremy|url=http://www.usgamer.net/articles/the-best-genesis-and-sega-cd-games|title=The 10 Best Genesis/Mega Drive and Top 5 Sega CD Games|work=USgamer|date=October 29, 2013|access-date=May 27, 2015|url-status=live|archive-url=https://web.archive.org/web/20150504005843/http://www.usgamer.net/articles/the-best-genesis-and-sega-cd-games|archive-date=May 4, 2015}}</ref><ref>cf. {{cite web |last=Semrad |first=Steve and ''EGM'' |url=http://www.1up.com/do/feature?pager.offset=3&cId=3147448 |title=The Greatest 200 Videogames of their Time, Page 3 |website=[[1UP.com]]|date=February 2, 2006 |access-date=December 11, 2016 |url-status=dead |archive-url=https://archive.today/20120713133949/http://www.1up.com/do/feature?pager.offset=3&cId=3147448 |archive-date=July 13, 2012 }} cf. {{cite web |url=http://www.ign.com/articles/2000/06/06/top-25-games-of-all-time-21-25 |title=Top 25 PlayStation Games of all Time: #21–25 |website=[[IGN]]|date=June 5, 2000 |access-date=May 19, 2014 |url-status=live |archive-url=https://www.webcitation.org/6EAQc8myb?url=http://www.ign.com/articles/2000/06/06/top-25-games-of-all-time-21-25 |archive-date=February 3, 2013}} cf. {{cite magazine|title=Retro Reviews: Lunar: Silver Star Story Complete|magazine=[[Game Informer]]|issue=148|volume=15|date=August 2005|page=119}}</ref><ref>{{cite web|last=Chen |first=David |url=http://www.1up.com/features/retroactive-metal-gear |title=Retroactive: Kojima's Productions |website=[[1UP.com]] |date=December 14, 2005 |access-date=December 11, 2016 |url-status=dead |archive-url=https://archive.today/20121209003855/http://www.1up.com/features/retroactive-metal-gear |archive-date=December 9, 2012 }}</ref> Although Sega created ''[[Streets of Rage (video game)|Streets of Rage]]'' for the Genesis to compete against the SNES port of the arcade hit ''[[Final Fight (video game)|Final Fight]]'', the Sega CD received an enhanced version of ''Final Fight'' that has been praised for its greater faithfulness to the arcade original.<ref>{{cite book|last=Kent|first=Steven L.|title=The Ultimate History of Video Games: The Story Behind the Craze that Touched our Lives and Changed the World|year=2001|publisher=Prima Publishing|location=Roseville, California|isbn=0-7615-3643-4|pages=445, 448}}</ref><ref>{{cite magazine|title=Retro Reviews: Final Fight CD|magazine=[[Game Informer]]|issue=177|volume=18|date=January 2008|page=110}}</ref> ''[[Eternal Champions: Challenge from the Dark Side]]'' was noted for its impressive use of the Sega CD hardware as well as its violent content.<ref>{{cite web|url=http://www.gamespot.com/features/vgs/sat/segafight/page11.html |title=The History of Sega Fighting Games, Page 11 |website=[[GameSpot]] |year=1997 |access-date=May 20, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20090517084728/http://www.gamespot.com/features/vgs/sat/segafight/page11.html |archive-date=May 17, 2009 }}</ref><ref>{{cite magazine|title=Eternal Champions: Challenge from the Dark Side|magazine=[[Next Generation (magazine)|Next Generation]]|date=February 1995|issue=2|volume=1|page=99}}</ref> In particular, ''Sonic CD'' garnered acclaim for its graphics and [[time travel]] gameplay, which improved upon the traditional [[Sonic the Hedgehog|''Sonic'']] formula.<ref name="1UP" /><ref>{{cite magazine|last=Noble |first=McKinley |url=http://www.gamepro.com/article/features/210105/the-20-best-platformers-1989-to-2009-page-2 |title=The 20 Best Platformers, 1989 to 2009, Page 2 |magazine=[[GamePro]]|date=August 4, 2009 |access-date=May 19, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20091128161652/http://www.gamepro.com/article/features/210105/the-20-best-platformers-1989-to-2009-page-2 |archive-date=November 28, 2009 }}</ref><ref>{{cite web|last=Towell|first=Justin|url=http://www.gamesradar.com/sonic-cd-review/|title=Sonic CD Review|website=[[GamesRadar+]]|date=December 16, 2011|access-date=May 19, 2014|url-status=live|archive-url=https://web.archive.org/web/20160304081914/http://www.gamesradar.com/sonic-cd-review/|archive-date=March 4, 2016}}</ref><ref>{{cite magazine|last=Rudden|first=Dave|url=http://www.oxmonline.com/sonic-cd-review|title=Sonic CD Review|magazine=[[Official Xbox Magazine]]|date=December 19, 2011|access-date=May 19, 2014|url-status=live|archive-url=https://web.archive.org/web/20120106112737/http://www.oxmonline.com/sonic-cd-review|archive-date=January 6, 2012}}</ref><ref>{{cite web|last=Kemps|first=Heidi|url=http://www.gamespot.com/reviews/sonic-cd-review/1900-6348147/|title=Sonic CD Review|website=[[GameSpot]]|date=January 3, 2012|access-date=May 19, 2014|url-status=live|archive-url=https://web.archive.org/web/20140329082842/http://www.gamespot.com/reviews/sonic-cd-review/1900-6348147/|archive-date=March 29, 2014}}</ref><ref>{{cite web|last=DeVries|first=Jack|url=http://www.ign.com/articles/2011/12/16/sonic-cd-review-2|title=Sonic CD Review|website=[[IGN]]|date=December 15, 2011|access-date=May 19, 2014|url-status=live|archive-url=https://web.archive.org/web/20140218230324/http://www.ign.com/articles/2011/12/16/sonic-cd-review-2|archive-date=February 18, 2014}}</ref> The Sega CD also received enhanced ports of Genesis games including ''[[Batman Returns (video game)|Batman Returns]]'' and ''[[Ecco the Dolphin (video game)|Ecco the Dolphin]]''.<ref name="RetroGamer" />

The Sega CD library includes several [[FMV game]]s, such as ''Night Trap, [[Dragon's Lair (1983 video game)|Dragon's Lair]]'' and ''[[Space Ace]]''.<ref name="CDFollies" /> FMV quality was substandard on the Sega CD due to poor video compression software and limited color palette,<ref name="CDFollies" /> and the concept never caught on with the public.<ref name="AllgameCD" /> According to Digital Pictures founder Tom Zito, the Sega CD's limited color palette created "a horrible grainy look".<ref name="segacd" /> Likewise, most Genesis ports for the Sega CD featured additional FMV sequences, extra levels, and enhanced audio, but were otherwise identical to their Genesis release.<ref name="AllgameCD" /> The video quality in these sequences has been criticized as comparable to an old [[VHS]] tape.<ref name="CDFollies" />

Given a large number of FMV games and Genesis ports, the Sega CD's game library has been criticized for its lack of depth.<ref name="CDFollies" /> Kalinske felt this was a valid criticism, and that while it was useful for releasing collections of games, "just doing cartridge games on a CD-ROM was not a step forward". According to Thorpe, the Sega CD's games did not display enough advancement to justify the console price for most consumers.  He felt that FMV games, targeted toward more casual players, were not enough to satisfy hardcore players.<ref name=":0" />

==Reception and legacy==
[[File:Sega-Genesis-Model-2-Monster-Bare.jpg|thumb|A model 2 Sega CD with a model 2 Genesis and a [[32X]] attached. Each device requires its own power supply.]]
Near the time of its release, the Sega CD was awarded Best New Peripheral of 1992 by ''[[Electronic Gaming Monthly]]''. Four separate reviews scored the add-on 8, 9, 8, and 8 out of 10; reviewers cited its upgrades to the Genesis as well as its high-quality and expanding library of games.<ref name="egmbuyersguide1993">{{cite magazine |date=January 1993 |title=Electronic Gaming Monthly's Buyer's Guide |magazine=[[Electronic Gaming Monthly]]}}</ref> In 1995, four ''Electronic Gaming Monthly'' reviewers scored it 5 out of 10, citing its limited game library and substandard video quality.<ref name="egmbuyersguide1995">{{cite magazine |date=January 1995 |title=Electronic Gaming Monthly's Buyer's Guide |magazine=[[Electronic Gaming Monthly]]}}</ref> ''[[GamePro]]'' cited the same problems, noting that many games were simple ports of cartridge games with minimal enhancements; ''GamePro'' concluded that the Sega CD was merely "a big memory device with CD sound" rather than a meaningful upgrade. They gave it a "thumbs sideways" and recommended that Genesis fans buy an SNES before considering a Sega CD.<ref>{{cite news|title=System Shopper|work=[[GamePro]]|issue=53|date=December 1993|pages=46–49}}</ref> In a special Game Machine Cross Review in May 1995, ''[[Famicom Tsūshin]]'' scored the Japanese Mega-CD 2 17 out of 40.<ref>{{cite magazine |year=1995 |title=Game Machine Cross Review: メガ-CD2 |magazine=[[Weekly Famicom Tsūshin]]|issue=335 |pages=166 |language=ja}}</ref>

Retrospective reception of the Sega CD has been mixed, praising certain games but criticizing its value for money and limited upgrades over Genesis.<ref name="CDFollies" /><ref name="1UP" /><ref name="failure" /> According to ''GamePro,'' the Sega CD is the seventh-lowest-selling console; reviewer Blake Snow wrote: "The problem was threefold: the device was expensive at $299, it arrived late in the 16-bit life cycle, and it didn't do much (if anything) to enhance the gameplay experience." However, Snow felt that the Sega CD had the greatest ''Sonic'' game in ''Sonic CD''.<ref name="failure" /> ''[[IGN]]'''s Levi Buchanan criticized Sega's implementation of CD technology, arguing that it offered no new gameplay concepts.<ref name="CDFollies" /> Jeremy Parish of ''[[Gamer Network|USgamer]]'' wrote that Sega was not the only company of the period to "muddy its waters" with a CD add-on, and highlighted some "gems" for the system, but that "the benefits offered by the Sega CD had to be balanced against the fact that the add-on more than doubled the price (and complexity) of the [Genesis]."<ref>{{cite web|last=Parish|first=Jeremy|date=August 14, 2014|title=Sega Genesis 25th Anniversary: The Rise and Fall of an All-Time Great|url=http://www.usgamer.net/articles/the-true-16-bit-experience-segas-genesis-turns-25|url-status=live|archive-url=https://web.archive.org/web/20150527115400/http://www.usgamer.net/articles/the-true-16-bit-experience-segas-genesis-turns-25|archive-date=May 27, 2015|access-date=May 27, 2015|work=[[USgamer]]}}</ref> In a separate article for ''[[1Up.com]]'', Parish praised the Sega CD's expansion of value to the Genesis.<ref name="1UP2">{{cite web|author=Parish, Jeremy|date=October 16, 2012|title=20 Years Ago, Sega Gave Us the Sega CD|url=http://www.1up.com/features/sega-cd-anniversary|url-status=dead|archive-url=https://archive.today/20130615202428/http://www.1up.com/features/sega-cd-anniversary|archive-date=June 15, 2013|access-date=December 11, 2016|website=[[1UP.com]]}}</ref> Writing for ''Retro Gamer'', Damien McFerran cited various reasons for the Sega CD's limited sales, including its price, lack of significant enhancement to the Genesis, and the fact that it was not a standalone console.<ref name="RetroinspectionCD"/> ''Retro Gamer'' writer Aaron Birch, defended the Sega CD as "ahead of its time" and said that game developers had failed to meet the potential of CD technology.<ref name="RetroGamer" />

Sega's poor support for the Sega CD has been criticized as the first step in the devaluation of the Sega brand. Writing for ''IGN'', Buchanan said the Sega CD, released without a strong library of games, "looked like a strange, desperate move—something designed to nab some ink but without any real, thought-out strategy. Genesis owners that invested in the add-on were sorely disappointed, which undoubtedly helped sour the non-diehards on the brand."<ref name="CDFollies" /> In ''GamePro'', Snow wrote that the Sega CD was the first of several poorly supported Sega systems, which damaged the value of the brand and ultimately led to Sega's exit from the hardware market.<ref name="failure">{{cite magazine|url=http://www.gamepro.com/gamepro/domestic/games/features/111822.shtml |title=The 10 Worst-Selling Consoles of All Time |author=Snow, Blake |date=July 30, 2007 |magazine=[[GamePro]]|access-date=May 20, 2008|archive-url=https://web.archive.org/web/20070508014611/http://www.gamepro.com/gamepro/domestic/games/features/111822.shtml|archive-date=May 8, 2007}}</ref> Thorpe wrote that, while it was possible for Sega to have brushed off the Sega CD's failure, the failure of the Sega CD and the 32X together damaged faith in Sega's support for its platforms.<ref name=":0" />

Former Sega of America senior producer Scot Bayless attributes the unsuccessful market to a lack of direction from Sega with the add-on. According to Bayless, "It was a fundamental paradigm shift with almost no thought given to consequences. I honestly don't think anyone at Sega asked the most important question: 'Why?' There's a rule I developed during my time as an engineer in the military aviation business: never fall in love with your tech. I think that's where the Mega-CD went off the rails. The whole company fell in love with the idea without ever really asking how it would affect the games you made."<ref name="RetroinspectionCD"/> Sega of America producer Michael Latham said he "loved" the Sega CD, and that it had been damaged by an abundance of "Hollywood [[interactive film]] games" instead of using it to make "just plain great video games".<ref name="Sega-16 Michael Latham">{{cite interview|last=Latham|first=Michael|interviewer=Ken Horowitz|title=Interview: Michael Latham|url=http://www.sega-16.com/2005/02/interview-michael-latham/|access-date=May 19, 2014|archive-url=https://web.archive.org/web/20150725023140/http://www.sega-16.com/2005/02/interview-michael-latham/|archive-date=July 25, 2015|url-status=live|work=Sega-16|date=February 8, 2005}}</ref> Former Sega Europe president Nick Alexander said: "The Mega CD was interesting but probably misconceived and was seen very much as the interim product it was."<ref name="Sega-16 Nick Alexander">{{cite interview|last=Alexander|first=Nick|interviewer=Ken Horowitz|title=Interview: Nick Alexander|url=http://www.sega-16.com/2008/09/interview-nick-alexander/|access-date=May 19, 2014|archive-url=https://web.archive.org/web/20160304032410/http://www.sega-16.com/2008/09/interview-nick-alexander/|archive-date=March 4, 2016|url-status=live|work=Sega-16|date=September 17, 2008}}</ref> Kalinske said that the Sega CD had been an important learning experience for Sega for programming for discs, and that it was not a mistake but not "as dramatically different as it needed to be".<ref name=":0" />

==See also==
{{Portal|Video games}}
* [[64DD]]
* [[Atari Jaguar CD]]
* [[Family Computer Disk System]]
* [[Virtual Boy]]

==Notes==
{{notelist}}

==References==
{{Reflist|30em}}

{{Sega Genesis}}
{{Sega hardware}}
{{Fourth generation game consoles}}

[[Category:CD-ROM-based consoles]]
[[Category:Fourth-generation video game consoles]]
[[Category:Products introduced in 1991]]
[[Category:Products and services discontinued in 1996]]
[[Category:Sega Genesis|Mega-CD]]
[[Category:Video game console add-ons]]
[[Category:68k-based game consoles]]