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Night Trap

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The Mega CD ( or Sega CD in the US ) is an add-on CDROM drive for the Sega Mega Drive. The Mega CD is termed a “notable failure” considered to be one of Sega’s mistakes, yet it’s very existence made it possible for the future CD ROM based systems around today to become a reality as well as teaching a valuable lesson to other companies in the console business; being that the market was not yet ready for a CDROM based system.


Development of the Mega CD was top secret. The engineers and programmers of the day were not well informed about what exactly it was they were building. These people were also required to sign a secrecy agreement with Sega about how the system was developed. People programming the first games were told to start programming with very large cartridge concept in mind.

This was probably because at the time the Mega CD was going to be only the second CD ROM on the market. The first company to bring a CDROM console was NEC with the PC Engine which the Mega CD was to directly compete and also bolster the Mega Drive against the Super Nintendo.

At the time the specs of the add-on were pretty impressive. CDROM drives had only just became available to PC owners, an additional Motorola CPU and a dedicated ASIC for sprite trickery and a new sound PCM based sound chip and loads of additional memory. As a result an almost new system was constructed based on the tried and trusted Mega Drive architecture.


In Japan the Mega CD launched December 1 1991 with an initial retail price of 49800 Yen which is about $380. Because of the high price and very little change the original launch titles bought with them in terms of difference from their Mega Drive counterparts, the system did not achieve decent sales and was largely ignored by consumers and third party developers. This was further reinforced by the launch titles being Heavy Nova and Sol-Feace.

I was not until Game Arts released Lunar: The Silver Star, their acclaimed RPG, that people began to notice the system. As sales improved because of this title developers began to sign up for games also. RPGs were what the system became known for. With the games being on CD dozens more times the amount of graphics and text could be added which is what the gamers wanted instead of grainy FMV. It was the Mega CD’s first killer app in Japan.

JVC had licensed the Mega CD technology and made their own machine - the WonderMega which was a Mega Drive and Mega CD combined with some additional features. This was only ever released in Japan with a whopping price of ?

With the increase in sales Sega decided to redesign the system. The Mega CD 2 was a slinkier design and sat at the side of the Mega Drive rather than on top with a top loading CDROM rather than front loading.

Ultimately the Mega CD did not become the revolution in console gaming that it was designed to be. The system managed to sell between 2 to 3 Million units during it’s time on the Japanese market.


The Mega CD was renamed Sega CD for the US market. The unit launched November 1992 at an initial launch price of $299 with Sega Classics 4-in-1, Sol-Feace, Sherlock Holmes and 2 CD+G samplers. Sega of America hyped the machine a full year before the consumers would ever see it.

The system was initially a success. The first shipment of 50,000 units sold out in 3 weeks. The second batch arrived just before Christmas and had the packaged title of Sega Classics 4-in-1 (Streets of Rage, Golden Axe, Columns and Revenge of Shinobi ) upgraded to 5-in-1 ( same as 4-in-1 with Super Monaco GP ). The initial success was largely due to the controversy caused by one game: Night Trap. The really controversial yet harmless and crap actually interactive movie. The game was about protecting 5 pretty teenage girls from strange occurrences in a house where they are spending the night. This sparked a whole investigation into the effects of violence on games.

As the Night Trap raucous went away so did the sales with not many titles warranting a purchase appearing. The system continued to be bombarded with the Interactive movies that everybody hated as well as a few Mega Drive conversions that did not really improve over their originals. Within a year the system went from being almost on top of the game market to the bottom. Approx 2.5 million units were sold in total.


The Mega CD was released in Britain April 1993 with an astronomical retail price of £270. Surprisingly 60,000 units out of 70,000 that were allocated for Britain had been sold by August. The “whole Night Trap thing” also played out in Europe even getting a spot on News at Ten prior to the games release.

With the first shipment of machines selling out Sega were anxious to get the redesigned Mega CD 2 onto the market and it arrived in October 1993 and continued to sell reasonably well. The system shipped with Sega Classics 5-in-1, Sol-Feace and Cobra Command.

The system received the same onslaught of FMV titles that the US suffered creating the same stigma around the unit for rubbish interactive movies and rightly so.

The Mega CD plodded on selling slowly until 1995 when the last games were released selling less than 1 million units for the whole of Europe.

The Hardware

| Specifications |


Motorola 68000 @ 12.5MHz
Runs in sync with Mega Drive CPU


6Mbit (program, picture data, sound data)
512Kbit PCM Wave Form Memory
128Kbit CDROM cache
64Kbit Backup memory

Boot ROM

CD Player Software
CD+G Compatability


Sega Custom AIC
Hardware Sprite Scaling and Rotation


PCM Sound Source
Stereo 8 channels
Wavelength Sampling 32KHz max

D/A Convertor

16 Bit D/A Convertor
8x internal over-sampling digital filter
PCM and CD sound mixing

Audio Characteristics

Wavelength characteristics: 20Hz to 20KHz
Signal v. Noise Ratio (S/N): Over 80db(1KHz)(Line Out)
Stereo Channel Seperation: Over 90db

CD Drive Unit

CD Diameter: 12cm and 8cm
Rotational Direction: Counter-clockwise (relative to the side opposite from the label)
Average Access Time: 0.8 sec

Audio Output

Line Out: RCA pin jack x2 (L/R)

Audio Input

Mixing: Stereo jack mixing

Battery Back-up
Secondary duration

1 month

When you first power on your Mega CD you will be treated to a little graphical show. What appears on screen varies depending on what model and region machine you have. The graphics are accompanied by a background jungle.

Check out the BIOS page for all the versions.
European BIOS Version 1.00

| European BIOS Version 1.00 |

| BIOS Versions Page |

When a game is in the drive it will be checked by the system. This is for region checking presumably. If a game passes you will get a press start message. Pressing A B or C here will take you to the CD player BIOS. The player appears automatically if the CD does not pass the check that it is actually a game.

The boot sequence is a large Sega logo in the centre of the screen with Sonic standing to the left.
Mega CD Boot Sequence

| Mega CD Boot Sequence |

The Mega CD adds another Motorola 68000 CPU to the Mega Drive design running at a swift 12.5Mhz. These CPUs run in sync with each other for parallel processing. Sega had already had some parallel processing abilities with dual Motorola CPUs in some of their arcade cabinets. When games are loaded proprietary code is read from the CD to sync the CPUS.

The graphics ASIC is a custom chip designed by Sega. It allows for a variety of hardware sprite functions such as scaling and rotation, bi-axial scaling and rotation, super smooth sprite animation and some FMV abilities amongst others. All of these features directly matched that of the Super Nintendo’s MODE7 abilities. Some of the Mega CD’s best ever games used these features to their fullest. This chip worked with the Mega Drives existing VDP using overlay and other techniques.

What the chip did not do, however, was improve colour which was desperately needed to make decent quality FMV. The system was still limited to 64 colours onscreen simultaneously out of a palette of 512. Apparently the designers did want to do this but it would have significantly upped the cost of the unit. Later there were several programming techniques that allowed for more colours to be displayed at once. Early attempts at FMV only used a third of the size of the screen and was very grainy. Later as compression became better full screen FMV was available along with some more colours but this was still relatively grainy. Some FMV games manage to get 128 colours.

The new PCM (Pulse Code Modulation) based sound chip adds 8 channels for much cleaner sound samples to be used from a wider library as well as better background tunes. This chip is another Sega custom design and again is used in conjunction with the Mega Drives existing sound chip for extra audio channels and effects. A stereo mixing lead is provided with the console which takes output from the headphone socket on the front of the Mega Drive and into a mixing jack on the back of the Mega

The Mega CD adds substantially more memory to the console. 6Mbit of main work RAM which was almost the size of a cartridge based game in those days being on average 8Mbit. There is a small cache for the CDROM drive, some local memory for the PCM chip to store samples and the innovation of Internal Back Up memory, something the Playstation STILL does not have today. This was quite an amount for the day storing on average 8 game saves with high scores etc. Very useful for those RPGs.
Internal Memory Manger Internal Memory Manger

| Internal Memory Manager |

| Internal Memory Manager |

The actual CD ROM drive itself is a single speed drive with an appalling seek rate of >1 second. The redesigned models have this improved slightly. Both 3 inch and 5 inch CD’s can be used.

The CD audio abilities are pretty standard and were relatively new in the use of games. The playback of Audio CDs was pretty useful as stereos with CD Players were still relatively new and expensive. The Phono outputs on the back of the unit means easy connection to a stereo so you were not limited to the usually crap audio output of the TVs of the time. The use of CD audio tended to be neglected by many developers. The majority of games sported dreadful CD audio tracks although there were a few exceptions. Some developers included some excellent sound tracks which went well with the action on the screen.

The CD+G ability was hardly ever used. It is a standard for including some graphics along with CD audio tracks. As the system could only display 64 colours at once the graphics were not likely to be very good anyway. The most used application of this feature was in Kareoke as the words appear with the music and don’t really need graphics.


As with any Sega console there are the accessories.

Memory Cartridge - Basically more internal memory on a cartridge. The memory manager in the system BIOS allows for the moving of data to and from machine to cartridge and back again.

Kareoke Add-on - The afore mentioned use of CD+G for Kareoke spawned a Kareoke add-on for the machine. Only ever released in Japan where Kareoke was more popular.

Country Converter - The Mega CD has the same territory lock outs as any Sega console. This device looks like a standard cartridge and plugs into the Mega Drive. It bypasses the country code of a game to make it playable. Not all games were compatible with this. Future revisions of the Mega CD’s BIOS prevented more games from being compatible.

Justifier Gun - For use with the game Lethal Enforcers. Just a standard light gun that plugs into your controller port. The gun also has a port for the connection of a second player. It is a very unsightful blue casing.

The Games

Unfortunately good games on the Mega CD were few and far between. However, what good games there was tended to be some of the best examples from the 16-BIT era.

With the advent of CD ROMs housing data and especially games, developers, with Sega included, seemed to try at every opportunity they had to attempt playback of FMV in the form of the dreaded “Interactive Movie”. From looking at the releases of games through out the consoles life it is obvious that massive FMV projects obviously out of the league of the machine were squeezed into the hardware usually bringing miserable results. It was relatively clear from the start with the torturous experiences like Night Trap and the entire Make My Video series that the Interactive Movie genre was not what gamers wanted. Unfortunately, developers persisted giving the system a reputation of housing only crap Interactive Movies.
Night Trap Tomcat Alley

| Night Trap |

| Tomcat Alley |

From the early attempts of Night Trap right throughout to Tomcat Alley the only improvements that can be noted are the fact that the FMV becomes full screen in the later. The same rubbish, repetitive gameplay remains intact. There is actually very little gameplay because you are watching a movie. A very bad one usually.

The Mega CD also received many “Hand-Me-Down” titles of Mega Drive games slighty enhanced with CD audio tracks an animated intro. Very little changed from it’s cartridge cousin other than the addition of loading times and sometimes the chance to save progress because of the extra memory inside the machine. Gameplay remained unchanged making creating very little reason to purchase a CD version of the same game. A perfect example of this is Sol-Feace.

Sol-Feace is a port of it’s Mega Drive counterpart Sol-Deace. The game is virtually identical apart from CD audio and a few animation’s. It is just as well that the game shipped with the system instead of actually going out and paying for it. Probably one of the most offensive examples is Mortal Kombat CD. Both Sega and third party developers were guilty of the “Hand Me Down” crime.

There is, however, a exceptions to this rule. Eternal Champions demonstrated the improvements a CDROM can bring to a cartridge based game. Although Eternal Champions had originally been released on the Mega Drive its CD version was almost an entirely new game. The game is a 1 on 1 2D beat-em-up. From the Mega Drive version almost [20] new characters were added, decent CD audio, a FMV intro and background to each character, improved speed, reworked gameplay, more moves per character, raised difficulty level and outstanding graphics and probably the goriest and elaborate death moves ever earning the game an 18 certificate. Eternal Champions is the only game to manage to get 256 colours out of the Mega CD with graphics programming tricks. Previous games managed 128 and Snatcher comes in with 192. Other games like Ecco the Dolphin did improve on their cartridge counterparts but not significantly enough to warrant a second purchase. Eternal Champions: Challenge from the Dark Side eventually went on to be packed with the Mega CD 2 in Europe.
Eternal Champions Ecco 2: The Tides of Time

| Eternal Champions |

| Ecco 2: The Tides of Time |

Ecco 2 Feature...

Sonic made an appearance on the machine at the time when Sonic’s popularity was at it’s highest. The possibilities for a Sonic game on a CDROM seemed endless. Sonic CD was a time travelling Sonic only affair whereas Sonic 2 before it introduced the character of Tails. There was a few niggles with the game and it became clear that Sonic CD was not done by the same team who did the Sonic games on the Mega Drive. Although a good game and probably the best platformer to grace the Mega CD it was slightly different to the previous games in the series in both look and style. It does, however, stand as the largest 16Bit Sonic title taking into consideration the amount of levels the game has and it does have some funky sound tracks.
Sonic CD

| Sonic CD |

Sonic CD Feature...

Core Design produced a few titles which really showed what the Mega CD was capable of. Both games Thunder Hawk and Battlecorps used the graphics ASIC chip to create brilliant 3D environments (at the time) with some excellent gameplay. Thunderhawk was a helicopter combat sim although really much more action whereas Battlecorps was similar only in a tank type vehicle. Another AAA quality game was Soul Star. A sprite scaling space shooter with intense audio sound tracks.

| Thunderhawk |

Soul Star

| Soul Star |


| Silpheed |

Silpheed Feature...

Game Arts probably had the best games on the Mega CD. Their RPG game Lunar: The Silver Star was responsible for a dramatic increase in the number of sales of the machine in Japan. They later followed this title up with Lunar: Eternal Blue. Both games are generally regarded as probably the best games for the system and some might say the best RPGs ever. Game Arts also made another very impressive title Silpheed being a polygon based space shooter. The graphics in this game were close to those seen in some of the best arcade machines of the time as polygons were just coming into games.

Round Up

Basically the Mega-CD was too soon and not supported properly. Developers with their constant attempts at getting a full FMV project through a single speed CDROM drive with a 12Mhz processor killed the machine. The age of the cartridges still had not passed but the lesson learnt was that FMV is OK in a game as long as it is NOT the game.

The best games came front what Sega and the third party developers got out of the hardware with their games and not what they tried to put in. The powerful technology of the day that made up the Mega CD was ultimately what killed it because of developers trying to put overly ambitious games in the hardware rather than making good games out of what was in the hardware. All of the best games for the system follow the later approach and things may have turned out quite differently as a result.

The Mega Drive itself continued to strive on against the competition and receive another upgrade which is a different story.

The Mega CD is a piece of gaming history and comes recommended if you already own a Mega Drive provided of course you avoid all of those FMV titles.

Mega CD Today

The Mega CD is probably more far gone than the Sega Master System or Game Gear simply because it’s memory brings back flood of crap FMV type games. Though not entirely the case the amount of good games that actually became popular is very limited.

There are many fan sites on the net which pay homage to the console as they no doubt recognise the vast potential the machine had and they recognise the best games as being some of the best ever. A highly recommended site is Eidolons Inn. Strangely the system has received a small lease of life. A company calledGood Deal Games Unfortunately these are the FMV style yet they promise to release more types of games depending on sales. The aforementioned Lunar has recently been re-released by Game Arts for the Playstation.

Those looking to purchase a peice of Sega history, systems can be picked up sometimes at Game Station along with a few games. These games area generally the crap FMV ones but a few good ones show up every now and then. Locating the good games will take some searching. Game from Game Arts and Core Design come highly recommended.


UPDATE: Click here for downloads

The secrecy agreement with the engineers who designed the machine and Sega has been one of the primary reasons why emulation of the console has really only recently to come into existence. Now through much pain staking reverse engineering because of the lack of technical information available and the sheer programming skill of people in the emulation scene some working emu’s exist.

The emulators for the Mega CD are Windows based requiring DirectX. The BIOS files must be used and need to match up with the country of the game that you wish to play. These can be got from Eidolons Inn and of course you need a CDROM drive. These are the most popular:


AGES was the first emulator to EVER emulate the Mega CD. It began as a Mega Drive emulator for Windows which then included 32X support only to then include Mega CD support.


Steve Snake ( author of the KGEN ) returns with a new emulator for Windows which is probably the best ever. Pretty good compatibility with solid performance. Highly recommended.


Gens is the sister project to Kega and therefor the majority of features are similar. As usual these can all be picked up from VG-Network.

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