Years ago when the Sega Genesis was in the midst of a war with Nintendo and NEC, Sega came up with a great concept that they thought was going to shift the war into their favour. This idea was the Sega CD in addition to the 32X which I will touch on in a later article. While the Sega CD was a great concept on paper, it never gained the traction that it needed to and was discontinued within a few years. Find out the story behind one of the most infamous add-ons in the history of gaming.

Back in the early 1990s, the gaming industry was full of different companies trying different things with NEC, Atari, Sega, and Nintendo leading the way and each of them trying their own things. NEC was one of the first ones to try out a CD add-on with the interesting Turbo Grafx-CD, Atari releasing the ill-fated Jaguar CD, and Sony and Nintendo developing a CD add-on that would become the PlayStation after Nintendo began negotiating with Philips over the add-on which angered Sony. This was a simple time, everything was pretty much on cartridges up to this point and all these companies were looking for something to drive sales. Sega decided to try its hand at the Sega CD and what followed was one of a series of moves which would ultimately lead to Sega removing itself from the hardware market altogether.

The model 2 North American Sega CD and Genesis.

Sega tampered with the original Genesis a lot in the early 90s, there was heavy competition from Nintendo and other smaller companies breathing down their necks. They then came up with a couple decently thought out add-ons to the system that just didn’t pan out the way they envisioned. One was the 32X system, the other was the Sega CD. Throughout most of 1991 there was a lot of speculation among the gaming media that Sega would be unveiling an add-on to the aging Genesis, they didn’t disappoint and at the Tokyo Toy Show in 1991, they unveiled what would be known as the Sega CD.

Here’s the now infamous Night Trap:

The Sega CD cost a cool $299 MSRP at launch and didn’t have a ton of support from developers right away considering there were only 7 games at launch in North America, two of which being “Make Your Own Music Video” titles. The add-on still managed to sell well with all 50,000 launch units gone by Thanksgiving (3 weeks after launch) in 1992. The good sales continued until 1993 when a huge crusade by US Senator Joe Lieberman made things very difficult for Sega after he was given clips of Acclaim’s Mortal Kombat and Digital Pictures’ Night Trap. The whole thing was so blown out of proportion that it lead to the creation of the ESRB that we know today.

The Sega CD kept going after that and built up a decent library of CD titles with a little over 200 games in its library. The add-on had two primary variations, one of which was a front-loading tray that sat below the Genesis, the other was a top-loader that sat beside the Genesis. Production on the first variation ended in 1993 while production on the second variation ended in 1995 in anticipation of the Sega Saturn. There were 2.5 million units sold in North America alone, 6 million worldwide so the project definitely wasn’t a commercial failure but, the quality on the system was somewhat lacking.

The system specifications looked like this


The main CPU is a 12.5-MHz16-bit Motorola 68000 processor. The Mega Drive has the same processor, but at a lower clockrate of 7.67 MHz (NTSC) / 7.61 MHz (PAL). In the combined system, both processors run concurrently for Mega-CD games, and the Mega-CD processor is idle for Mega Drive games.


  • Graphics Processor: Custom ASIC
  • Number of simultaneous colors on screen: 64 out of 512
  • Display Resolution: 320 × 224 pixels and 256 × 224, video size from ¼ to full screen
  • Cinepak video compression scheme, implemented in software
  • Scaling and rotation effects
  • 500 MB CD-ROM discs (equivalent to 62 minutes of audio data)
  • CD-ROM drive transfer rate: 150 KB/s (1x)
  • Size: 1 MBit
  • Used for games, CD player, CD+G and karaoke
  • Access time: 800 ms

The Mega-CD adds the Ricoh RF5C164 chip, which gives 8 extra sound channels, all capable of sampled sounds, to the Mega Drive’s YM2612 and SN76489 chips (which provide a total of 18 channels, with the YM2612’s 6 channels and PSG’s 4). The drive did not have a board-level connection with the audio and required an additional connection to mix the sounds from the console and the drive (later version addressed this deficiency).

  • Sound format: Stereo PCM
  • Clock frequency of source: Up to 12 MHz
  • Sound channels: 8
  • Maximum sample rate: 32 kHz (44.1 kHz for CD-DA)
  • Wave data width: 8 bits
  • 16 bit DAC
  • 8x internal over-sampling digital filter
  • Frequency Range: 20 Hz – 20 kHz
  • Signal-to-Noise Ratio: > 90.0 dB @ 1K
  • Channel Separation: > 90.0 dB
  • Output: RCA stereo Pin Jack x2 (L/R) / SCART cable

As you can see, the Sega CD has very respectable specs for the early 1990s however, the stigma started to attach itself to the add-on when more and more FMV games started to utilize the hardware. These were mostly games based off movies and games that required very little user input. The video was grainy and pixelated and at times only took up a small box in the middle of the screen because the Sega CD was not meant to handle such tasks and thus could not produce a full screen FMV in most cases.

Here’s the intro to Kojima’s Snatcher:

If that wasn’t enough to hurt the legacy of the Sega CD, the amount of shovelware sure could be. Games that were previously released on the Genesis were sometimes re-released on the Sega CD with tiny enhancements that really didn’t make the game any different than on the Genesis. An examples of this is Mortal Kombat II. There were also games that used this to their advantage as was the case with Earthworm Jim which added new levels to the pre-existing game.

Overall, the Sega CD was the add-on that broke new ground for the CD format in the West along with its competitors and really paved the way for console like the PlayStation and the Dreamcast. There are still many Sega CD systems available today with a lot of them going for an average of $40 to$70 on eBay. The games are a bit on the rare side though with some fetching a great deal of cash. There were a lot of very basic games but there are definitely some gems out there if you do your research.

Here’s an ad from 1993

[Source 1]
[Source 2]


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