Sega CD

From Academic Kids

Missing image
Three versions of Sega CD: The Mega-CD 1 and 2 and the CDX/Multimega.

The Sega Mega (Japanese: メガCD) is an add-on device for the Sega Mega Drive released in Europe, Australia, and Japan. The North American version is called the Sega CD. The device allow the user to both play CD audio discs and specially designed game CDs. It can also play CD+G discs.

The development of the Sega CD was top secret; game programmers didn't know what they were designing for until the Mega-CD was finally revealed at Tokyo Toy Show in Japan. The Sega Mega-CD in Japan was designed to compete with the PC Engine, which had a separate CD-ROM drive.

The Sega Mega-CD was not meant to compete with the Super Famicom (Super Nintendo Entertainment System outside Japan).

At first, the Sega CD was a CD tray unit that sat under the console. The Sega CD 2 was a smaller, cheaper top loading drive that plugged next to the Sega Mega Drive.




Missing image
Hybrid Sega CD/Sound Minisystem manufactured by Aiwa

The Sega Mega-CD was released first in Japan in 1st December 1991. Its retail price was about ¥49,800. Initially, it was a great success because of the inherent advantages of CDs (high storage capacibility and the low cost of media). The fact that it had a nice RPG catalog also helped.

The system sold 100,000 units during the first year of release in Japan. However, cost issues prevented more units from being sold.

North America

Sega of Japan did not speak to Sega of America about their Mega-CD plans for that market until a few months later.

The Sega CD had been announced at the Chicago CES on November 1992. Early reports had suggested that hardware in the system would allow it to display more on screen colors (from a larger palette) then the Sega Genesis or the Super Nintendo, which was a important technical concern for consumers.

In the end, the Sega CD failed to convince North American gamers, mostly due to the cost of the console, and the lack of any hardware advancements. There just was not enough value for the price. Moreover, the game experience was little improved.

Sound was likely to be better if it included some CD audio tracks, but on the average, conventional games looked the same. Sega wanted to showcase the power of the Sega CD, and so focused on the "FMV" games rather than importing "extended" games that only expanded ordinary games by taking advantage of the extra storage space of the CD media. Sega insisted on licensing and producing primarily "full motion video" games similar to earlier laserdisc games, that were universally panned by game reviewers.

The single speed CD drive added load times to all games, and the 64-color graphics and underpowered processor (for video rendering) made these full-motion games look terrible.


In Europe the Mega-CD was overpriced. It was released in April 1993 in the United Kingdom for 270 (over €400 now). Only 4% of European Mega Drive owners bought a Mega-CD because of its price. Unlike The Mega Drive, which was a very successful console in Europe, only 60,000 of the 70,000 Mega-CD's shipped to Europe were sold by August 1993.

Some European countries (Spain for instance), wouldn't get the original Mega-CD, but the Mega-CD 2, which also slowed sales.


The Australians got their Mega-CD on 19 April, 1993.


The following models were released:

  • Sega Mega-CD I (Sega CD I in North America)
  • Sega Mega-CD II (Sega CD II in North America). Designed for the Mega Drive/Genesis II and to reduce manufacturing costs
  • JVC Wondermega (Xeye in North American release, never released in Europe), was a all-in one Genesis /Sega CD unit
  • Sega Multimega (called Sega CDX in North America). A portable CD player that plays both Mega Drive and Mega-CD games
  • Pioneer LaserActive Sega CD module, an add-on device you could add to a Laseractive Pioneer Laserdisc player


Missing image
Screenshot Battlecorps

Missing image
Screenshot Dune

Missing image
Screenshot Road Avenger

Missing image
Screenshot Sewer Shark

Battlecorps Dune Road Avenger Sewer Shark
Core Design (1994) Cryo (1994) Wolfteam (1992) Digital Pictures (1992)
Missing image
Screenshot Sonic CD

Missing image
Screenshot Third World War

Missing image
Screenshot Tomcat Alley

Sonic CD Third World War Tomcat Alley
Sega (1993) Micronet (1993) Sega (1994)

Technical Specifications


The main CPU is a 12.5-MHz 16-bit Motorola 68000 processor. The Mega Drive/Genesis has the same processor, but at a lower clock rate of 7.67 MHz.


  • Graphics Processor: Custom ASIC
  • Number of simultaneous colors on screen: 64 (Using programming tricks, this limit is increased to 128 colors via HAM "Hold and Modify")
  • Colors available in Cinepak and TruVideo modes: 128 to 256 colors
  • Video size from 1/4 to full screen
  • Advanced compression scheme
  • Software-based upgrade


  • Main RAM: 6 Mbit
  • PCM samples: 512 Kbit
  • CD-ROM data cache: 128 Kbit
  • 64 Kbit Internal Backup RAM

The Sega CD also features sprite enhancement effects such as scaling and rotation, similar to that of the Super Famicom/SNES Mode 7.


  • 500 MB CD-ROM discs (equivalent to 62 min of audio data)
  • 1/4 screen B/W footage video: 1.5 to 4 hours
  • 1/4 screen color footage: 45 minutes
  • CD-ROM drive transfer rate: 150 Kbytes/s (1x)

(Above specs prior to compression)


  • Size: 1 MB
  • Used for games, CD player, CD+G and karaoke
  • Access time: 800 ms
BIOS Revisions
BIOS Version Machine
1.00 Original Mega-CD
1.10 Original Mega-CD with motorized disk tray
2.00 Mega-CD 2 (Sega CD 2 in North America)
2.05 Mega-CD 2
2.10 Mega-CD 2
2.21 Sega Mega LD (Japan), Sega Multimega (Europe), CDX (North America)


The Sega CD adds 10 extra sound channels to the existing Genesis Z80 SPU.

  • Sound format: Stereo PCM
  • Sound channels: 8
  • Maximum sample rate: 32 KHz (44.1 KHz for CD-DA)
  • 16 bit DAC
  • 8x internal over-sampling digital filter
  • Frequency Range: 20 Hz - 20 KHz
  • Signal-to-Noise Ratio: > 900 dB @ 1K
  • Channel Separation: > 900 dB
  • Output: RCA stereo Pin Jack x2 (L/R) / SCART cable


Dimensions: 301mm x 212.5 x 112.5
Weight: 1.4 kg (3.1 lbs)

See Also

External links

ja:メガCD sv:Mega CD


Academic Kids Menu

  • Art and Cultures
    • Art (
    • Architecture (
    • Cultures (
    • Music (
    • Musical Instruments (
  • Biographies (
  • Clipart (
  • Geography (
    • Countries of the World (
    • Maps (
    • Flags (
    • Continents (
  • History (
    • Ancient Civilizations (
    • Industrial Revolution (
    • Middle Ages (
    • Prehistory (
    • Renaissance (
    • Timelines (
    • United States (
    • Wars (
    • World History (
  • Human Body (
  • Mathematics (
  • Reference (
  • Science (
    • Animals (
    • Aviation (
    • Dinosaurs (
    • Earth (
    • Inventions (
    • Physical Science (
    • Plants (
    • Scientists (
  • Social Studies (
    • Anthropology (
    • Economics (
    • Government (
    • Religion (
    • Holidays (
  • Space and Astronomy
    • Solar System (
    • Planets (
  • Sports (
  • Timelines (
  • Weather (
  • US States (


  • Home Page (
  • Contact Us (

  • Clip Art (
Personal tools