Sega Mega-CD
Encyclopedia
The is an add-on device for the Mega Drive video game console, designed and produced by Sega
Sega
, usually styled as SEGA, is a multinational video game software developer and an arcade software and hardware development company headquartered in Ōta, Tokyo, Japan, with various offices around the world...

 and released in Japan, Europe, Australia, New Zealand, and South Africa. The device was also released in North America under the name Sega CD, for the Sega Genesis. The device adds a CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

 drive to the console, allowing the user to play CD-based games and providing additional hardware functionality. It can also play audio CD
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

s and CD+G
CD+G
CD+G is an extension of the compact disc standard that can present low-resolution graphics alongside the audio data on the disc when played on a compatible device...

 discs.

The development of the Mega-CD was confidential; game developers were not made aware of what exactly they were working on until the add-on was finally revealed at the Tokyo Toy Show in Japan. The Mega-CD was designed to compete with the PC Engine CD (TurboGrafx-16 CD) in Japan, which had a separate CD-ROM drive.

The first version of the Mega-CD sits underneath the Mega Drive console and loads CDs via a motorized tray. A second version places a top-loading CD-ROM drive to the right of the console and is intended primarily for use with the redesigned Sega Mega Drive 2. Both versions of the Mega-CD are compatible with the initial two versions of the Mega Drive console, but not with the Mega Drive 3 or Genesis 3.

Japan

The Mega-CD was released first in Japan on December 12, 1991. By March 1994 the Mega-CD had sold 380,000 units in Japan, — 11% of Japanese Mega Drive owners.

North America

The Sega CD had been announced at the Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

 CES
Consumer Electronics Show
The International Consumer Electronics Show is a major technology-related trade show held each January in the Las Vegas Convention Center, Las Vegas, Nevada, United States. Not open to the public, the Consumer Electronics Association-sponsored show typically hosts previews of products and new...

 in June 1992. The advertising boasted full-motion video clips and CD audio soundtracks, although because of the Genesis's limited color palette and limited data bandwidth, motion video was heavily dithered and usually limited to a small rectangle in the centre of the screen.

Europe

In Europe the Mega-CD was released in April 1993. 60,000 of the 70,000 Mega-CDs shipped to Europe were sold by August 1993.

Some European countries (Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 for instance), would not see a release of the original Mega-CD, but the Mega-CD 2.

Brazil

The Sega CD 2 was launched in the Brazilian market at exactly the same time as the North American release. Since the original Sega CD was never released there, it was simply called "Sega CD". However, because several Mega-CD units imported from Japan were already in the market, it was informally known as "Mega-CD". It was manufactured locally by Tec Toy
Tec Toy
Tectoy is a Brazilian videogame and electronics company. They are best known for publishing and distributing Sega's consoles and video games in that country. The company stock is also traded at Bovespa...

.

Reception

Sega wanted to showcase the power of the Mega-CD, however with the actual capacity of Mega Drive cartridges being small (hundreds of Mega Drive cartridges could fit on one CD), there were not many companies ready to adapt to the larger capacity of the storage medium, especially when they were hindered by the game systems' limitations.

Seeing the technology already in use for laserdisc classic arcade, and even a few titles on the PC Engine, video seemed to be the best choice at the time. So they focused on "FMV" games. Sega started off licensing and producing primarily "full motion video" games similar to earlier Laserdisc
Laserdisc
LaserDisc was a home video format and the first commercial optical disc storage medium. Initially licensed, sold, and marketed as MCA DiscoVision in North America in 1978, the technology was previously referred to interally as Optical Videodisc System, Reflective Optical Videodisc, Laser Optical...

 games, that were initially praised by reviewers (for example: Gamepro's "SWAT PRO" magazine initially gave Sewer Shark
Sewer Shark
Sewer Shark is a first-person rail shooter game, the first video game for a game console to use full-motion video for its primary gameplay. It was originally slated to be the flagship product in Hasbro's NEMO video game system, which would use VHS tapes as its medium. However, Hasbro cancelled the...

 a perfect score, then later re-reviewed it with a much lower score as their feelings toward the system changed)

Eventually, most FMV games became universally panned by game reviewers, no matter which console the game was designed for. The Mega CD's limited 512-color palette (of which a maximum of 64 colors were displayable simultaneously), combined with the processor not being well-suited for video, resulted in grainy, dithered images running at a lower framerate and resolution in most games.

Another criticism of the software library was that most titles consisted of "shovelware
Shovelware
Shovelware is a derogatory computer jargon term that refers to software noted more for the quantity of what is included than for the quality or usefulness...

", in which a developer takes an existing title and adds minor new content (usually a CD audio soundtrack, or video sequences) while not expanding the original game itself. Few titles received major changes, but two exceptions were Earthworm Jim
Earthworm Jim
Earthworm Jim is a run and gun platform video game starring an earthworm named Jim in a robotic suit who battles evil. Created by Doug TenNapel and designed by David Perry, the game was developed by Shiny Entertainment and Playmates Interactive Entertainment, released by Sega for the Mega...

which featured additional levels and game changes, and The Amazing Spider-Man vs. The Kingpin
The Amazing Spider-Man vs. The Kingpin
The Amazing Spider-Man vs. The Kingpin is a video game produced by Sega of America and developed by Technopop...

, which featured many changes, which drastically restructured the game, making it less linear, and adding animated cut scenes.

Despite a somewhat lackluster library of games, the console introduced at least one notable franchise. The Lunar
Lunar series
The Lunar games, made by Game Arts and published in the United States by Working Designs, and later, Ubisoft and Xseed Games, are a series of console RPGs...

series, despite the relatively narrow circulation the two titles on the Mega-CD received, was critically acclaimed and became a cult classic, with both games receiving remakes for the PlayStation
PlayStation
The is a 32-bit fifth-generation video game console first released by Sony Computer Entertainment in Japan on December 3, .The PlayStation was the first of the PlayStation series of consoles and handheld game devices. The PlayStation 2 was the console's successor in 2000...

 and Sega Saturn
Sega Saturn
The is a 32-bit fifth-generation video game console that was first released by Sega on November 22, 1994 in Japan, May 11, 1995 in North America, and July 8, 1995 in Europe...

 in the late '90s; and a prequel to the series for the Nintendo DS
Nintendo DS
The is a portable game console produced by Nintendo, first released on November 21, 2004. A distinctive feature of the system is the presence of two separate LCD screens, the lower of which is a touchscreen, encompassed within a clamshell design, similar to the Game Boy Advance SP...

 in 2005. Another notable title was the cult-classic Snatcher
Snatcher
is a cyberpunk-themed graphic adventure game produced by Konami, originally released in Japan for the NEC PC-8801 and MSX 2 computer platforms in 1988. It was followed by a CD-ROM-based remake released for the PC Engine video game console in 1992, which was subsequently ported and localized into...

, a cyberpunk
Cyberpunk
Cyberpunk is a postmodern and science fiction genre noted for its focus on "high tech and low life." The name is a portmanteau of cybernetics and punk, and was originally coined by Bruce Bethke as the title of his short story "Cyberpunk," published in 1983...

 digital comic released by Konami
Konami
is a Japanese leading developer and publisher of numerous popular and strong-selling toys, trading cards, anime, tokusatsu, slot machines, arcade cabinets and video games...

 and designed by Hideo Kojima
Hideo Kojima
is a Japanese game director originally employed at Konami. He is currently the director of Kojima Productions and was promoted to Vice President of Konami Digital Entertainment in early 2011...

. Though Snatcher was already available on several platforms, the Mega-CD version was the only one released in English.

One exclusive game that was published for the Mega-CD is the now-famous Sonic the Hedgehog CD
Sonic the Hedgehog CD
, or Sonic CD, is a critically acclaimed 1993 platform video game in the Sonic the Hedgehog series, developed by Sonic Team for the Mega-CD/Sega CD. It marked the first official appearance of the characters Metal Sonic and Amy Rose...

, or Sonic CD. Sonic CD has been praised for its visual style, superior CD sound, and an innovative time-travel mechanic, allowing players to explore four versions of each stage.

The Mega-CD was awarded Best New Peripheral of 1992 by Electronic Gaming Monthly
Electronic Gaming Monthly
Electronic Gaming Monthly is a bimonthly American video game magazine. It has been published by EGM Media, LLC. since relaunching in April of 2010. Its previous run, which ended in January 2009, was published by Ziff Davis...

.

Models

The following models were released:
  • Mega-CD I (Sega CD I in North America)
  • Mega-CD II (Sega CD II in North America). Designed for the Mega Drive 2/2nd model Genesis (also compatible with the Mega Drive/1st model Genesis and included a special add-on for this purpose) and to reduce manufacturing costs.
  • JVC Wondermega RG M1 (JAPAN-ONLY (released on April 1, 1992): combination Mega Drive/Mega-CD player with enhanced sound, video and karaoke capabilities and a mechanized CD tray lid. Also included MIDI functionality. Sega themselves released on April 24, 1992 a variation of this unit with slight cosmetic changes, but functionality remains identical – Branded as Sega Wondermega)
  • JVC Wondermega Model RG M2 (JAPAN-ONLY: a second model with a different case design and wireless controller functionality built in. The mechanized CD tray was omitted in favour of a more conventional spring-loaded tray design. Otherwise, functionally identical to the Wondermega I. This model was stripped down released in the US as the X'Eye.)
  • Sega Multi-Mega (called Sega CDX in North America). A portable CD player that plays both Mega Drive and Mega-CD games, as well as audio CDs, and CD-G discs. Resembling a slightly longer version of the typical portable CD player of the day.
  • Pioneer LaserActive
    Pioneer LaserActive
    The Pioneer LaserActive was a short-lived Laserdisc-based game console released by Pioneer in 1993. In addition to LaserActive games, separately sold add-on modules expanded the hardware to include compatibility with the Sega Mega Drive/Sega Genesis and PC Engine/TurboGrafx 16 game cartridges and...

     Sega Mega-CD module, an add-on device available for the LaserActive system

CPU

The main CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

 is a 12.5-MHz 16-bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...

 Motorola 68000
Motorola 68000
The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...

 processor. The Mega Drive has the same processor, but at a lower clock rate
Clock rate
The clock rate typically refers to the frequency that a CPU is running at.For example, a crystal oscillator frequency reference typically is synonymous with a fixed sinusoidal waveform, a clock rate is that frequency reference translated by electronic circuitry into a corresponding square wave...

 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

  • Graphics Processor: Custom ASIC
  • Number of simultaneous colors on screen: 64 out of 512
  • Display resolution
    Display resolution
    The display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...

    : 320 × 224 pixels and 256 × 224, video size from ¼ to full screen
  • Cinepak video compression scheme, implemented in software
  • Scaling and rotation effects

RAM

  • Program RAM: 4 Mbit
    Megabit
    The megabit is a multiple of the unit bit for digital information or computer storage. The prefix mega is defined in the International System of Units as a multiplier of 106 , and therefore...

     (upgrade from the Mega Drive's 64 kbyte)
  • Word Ram: 2 Mbit
    Megabit
    The megabit is a multiple of the unit bit for digital information or computer storage. The prefix mega is defined in the International System of Units as a multiplier of 106 , and therefore...

    , this RAM is used as a bridge for the two processors
  • PCM samples: 512 kbit
    Kilobit
    The kilobit is a multiple of the unit bit for digital information or computer storage. The prefix kilo is defined in the International System of Units as a multiplier of 103 , and therefore,...

  • CD-ROM data cache: 128 kbit
  • 64 kbit Internal Backup RAM (for storing saved games, scores, etc. for CD games)

Storage

  • 500 MB CD-ROM
    CD-ROM
    A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

     discs (equivalent to 62 minutes of audio data)
  • CD-ROM drive transfer rate: 150 kB
    Kilobyte
    The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

    /s (1x)

BIOS

  • Size: 1 MBit
    Megabit
    The megabit is a multiple of the unit bit for digital information or computer storage. The prefix mega is defined in the International System of Units as a multiplier of 106 , and therefore...

  • Used for games, CD player, CD+G and karaoke
    Karaoke
    is a form of interactive entertainment or video game in which amateur singers sing along with recorded music using a microphone and public address system. The music is typically a well-known pop song minus the lead vocal. Lyrics are usually displayed on a video screen, along with a moving symbol,...

  • Access time: 800 ms
    Millisecond
    A millisecond is a thousandth of a second.10 milliseconds are called a centisecond....



When the Mega Drive + Mega-CD is powered on, the Mega Drive CPU gets control first. If a cartridge is inserted, the Mega Drive ROM starts it, and the Mega-CD remains idle, except for the audio mixer, which passes through the Mega Drive audio to its RCA outputs. If the cartridge slot is empty at power-up, a part of the BIOS is mapped to the Mega Drive CPU memory map and is run by the Mega Drive CPU, which decompresses other part of the BIOS onto the Mega-CD memory. Then the Mega-CD CPU runs other code of the BIOS. Both CPU run together a program which checks the disc while displaying a Mega-CD (or Sega CD) title animation with music utilizing the sound hardware of both the Mega Drive and the Mega-CD. If a game disc is inserted, it automatically loads the game after a few seconds, or immediately if Start is pressed on the controller. If a regular audio CD or a CD+G disc is inserted, it waits for button A, B, or C on the first controller to be pressed, then starts the GUI CD/CD+G player software in ROM. It will also run this software on a game disc if A, B, or C is pressed before the game auto-starts.

From the CD player, it is also possible to enter a utility to manage items in the game backup RAM and RAM carts, or to start an inserted Mega-CD game disc (without resetting the console). On all second revisions of the Mega-CD boot ROM, if the user has a Mega Mouse or Sega Mouse plugged into control port 2, this may be utilized as a pointing device instead of using a traditional control pad. If no disc is inserted, it prompts on screen for one while playing the title animation and music. Except when a game disc is in the drive, if no button is pressed at the Mega-CD title screen, the animation and music will loop indefinitely.

In the original Mega-CD model which has the motorized front-loading tray, pressing reset while the title screen is displayed will open the tray (eject the disc) or close it (load the disc). At all other times (without a cartridge inserted), pressing reset will return to the Mega-CD title screen, but will not open the tray. It is impossible to open the motorized tray with a cartridge inserted, as the BIOS which controls it will not run then. In the later version of the Mega-CD with the top-loading drive, resetting or powering off may leave the disc spinning, and the only way to stop the disc before opening the tray is to switch off the system and wait 15 to 30 seconds for it to spin down (under the light friction of the spindle motor bearings) or to enter the CD player mode and play or pause the disc, then stop (in BIOS v2.00, maybe others). After the disc can be heard to spin down while the lid is closed, whereas just pointing to Stop and pressing a button will not spin down the disc when the player is not in play or pause mode.












BIOS Revisions
BIOS Version Machine
1.02 Pioneer LaserActive Mega LD 1(Japan/North America) (based on ver. 0.98 proto Mega-CD BIOS)
1.00 Original Mega-CD (Europe/Japan), Sega WonderMega 1 (Asia) Victor WonderMega RG-M1 (Asia)
1.04 Pioneer LaserActive Mega LD 2 (North America) (based on ver. 1.10 Sega-CD BIOS)
1.10 Original Sega CD (North America)
2.00 Mega-CD 2 (Europe/Japan), Sega CD 2 (North America), Victor WonderMega RG-M2 (Asia), JVC X'eye (North America)
2.11 Mega-CD 2 (Europe/Japan), Sega CD 2 (North America)
2.21 Sega Multi-Mega (Europe), Sega Genesis CDX (North America)

Audio

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
    Pulse-code modulation
    Pulse-code modulation is a method used to digitally represent sampled analog signals. It is the standard form for digital audio in computers and various Blu-ray, Compact Disc and DVD formats, as well as other uses such as digital telephone systems...

  • 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
    Digital-to-analog converter
    In electronics, a digital-to-analog converter is a device that converts a digital code to an analog signal . An analog-to-digital converter performs the reverse operation...

  • 8x internal over-sampling digital filter
  • Frequency Range: 20 Hz – 20 kHz
  • Signal-to-Noise Ratio: > 90.0 dB
    Decibel
    The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...

     @ 1K
  • Channel Separation: > 90.0 dB
  • Output: RCA stereo Pin Jack x2 (L/R) / SCART
    SCART
    SCART is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together...

     cable

Other

  • Dimensions: 301 mm × 212.5 mm × 112.5 mm
  • Weight: 1.4 kg (3.1 lb
    Pound (mass)
    The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

    )

Accessories

  • Few accessories were released for the Mega-CD. The most notable being an external memory card that came in the form of a Mega Drive cartridge. Titled the "CD Backup RAM Cart", it was placed in the Mega Drive slot like a normal Mega Drive game, and the Mega-CD would detect this cartridge upon booting up. Games could either be saved directly to it (on the titles that supported it) or to copy/transfer game saves to and from the Mega-CD's internal RAM. Complete backups were possible as the CD Backup RAM Cart contained 16 times the amount of back-up RAM of the Mega-CD (1 Mbit
    Megabit
    The megabit is a multiple of the unit bit for digital information or computer storage. The prefix mega is defined in the International System of Units as a multiplier of 106 , and therefore...

    , or 2045 Game Save Blocks, compared to the Mega-CD's 64 kbit, or 125 Game Save Blocks.)
  • A Light gun
    Light gun
    A light gun is a pointing device for computers and a control device for arcade and video games.Modern screen-based light guns work by building a sensor into the gun itself, and the on-screen target emit light rather than the gun...

     named "The Justifier
    Konami Justifier
    The Konami Justifier was a light gun used in numerous video arcade and home console games developed and/or published by Konami and Sega. Konami manufactured variations of the gun for the Sega Genesis, Sega CD, Super Nintendo, and PlayStation consoles. The gun was similar in appearance to a Colt...

    " was also released bundled with Lethal Enforcers
    Lethal Enforcers
    Lethal Enforcers is a 1992 shooting game released for the arcades by Konami. It is best known for its revolver-shaped light gun known as the Konami Justifier, its digitized graphics, and the controversy over its content.Home versions were released for the Super NES, Sega Genesis and Sega CD during...

    .
  • A multi-functional unlicensed cartridge called "Megacart" was released in 2006. It works as a region converter, RAM cart and can flash cart games.

External links

  • Sega-16 – Comprehensive site with hundreds of reviews and articles.
  • SegaBase – Comprehensive history of this system.
  • Sega-Mega-CD-Library – Collectors Guide for the PAL SEGA Mega-CD.
  • Sega CD Universe – Sega CD site with reviews, photos, screen shots, cheats, and more.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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