Mega Drive

The Mega Drive (also known as the Genesis in North America) was SEGA's fourth-generation console. It was their 16-bit answer to Nintendo's Nintendo Entertainment System and NEC's TurboGrafx 16, since SEGA's their previous effort, the Master System, did not do well in North America or Japan. The system launched in Japan in 1988, and was then released in North America in 1989 and in Europe in 1990. The name changed in North America from Mega Drive to Genesis due to licensing issues. Everywhere else in the world, it remained the Mega Drive. The Mega Drive is SEGA's third console and the successor to the Master System with which it has backward compatibility when the separately sold Power Base Converter is installed.

The system boasted "blast processing", a type of processing that allowed fast like Sonic the Hedgehog and Ecco the Dolphin to run with little slow-down. The system was originally released with a tag that claimed "high-definition graphics"; in later models, the tag was removed along with the expansion port.

Overview
The Mega Drive was the first of its generation to achieve notable market share in continental Europe, where it competed against a wide range of platforms, including both dedicated gaming consoles and home computer systems. Two years later, Nintendo released the Super Nintendo Entertainment System, and the competition between the two would dominate the 16-bit era of video gaming. The console began production in Japan in 1988 and ended with the last new licensed game being released in 2002 in Brazil. The mega Drive was SEGA's most successful console; though SEGA has never released a total sales figure quote. Several add-ons were created including the Mega CD and 32X which extended its capabilities.

The controversy over games such as Mortal Kombat in the United States forced SEGA to create the first content rating system for video games, the Videogame Rating Council, rather than have the games heavily censored. The rating system allowed SEGA to ship games with little to no censorship and gave it a competitive edge when the same game was released by Nintendo. The success of those games eventually forced Nintendo to join its rating system.

The console and its games continue to be popular among fans, collectors, video game music fans, retro gamers, emulation enthusiasts and the fan translation scene. Licensed 3rd party variations of the console are still being produced to this day, and there are also several indie game developers continuing to produce games for the console. Many games have been re-released in compilations for newer consoles, or offered for download on various online services, such as the Nintendo eShop (including the Wii Virtual Console and Wii U Virtual Console), Xbox Games Store (for the Xbox 360), PlayStation Store (for the PlayStation 3) and Steam (currently only for Microsoft Windows systems).

Add-ons
The system had two major add-ons: the Mega CD (SEGA CD in North America), which was largely made to copy the TurboGrafx 16/TurboGrafx CD dynamic and was a small success; and the 32X, a failed attempt to extend the Mega Drive's life that was plagued with miscommunication between various parts of SEGA.

History
Although the Master System was a success in Europe, and later also Brazil, it failed to ignite much interest in the North American or Japanese markets, which, by the mid-to-late 1980s, were both dominated by Nintendo's large market shares. Meanwhile in the arcades, the SEGA System 16 had become a success. Hayao Nakayama, SEGA's CEO at the time, decided to make its new home system utilize a similar 16-bit architecture. The final design was eventually also used in the Mega-Tech, Mega-Play and System-C arcade machines. Any game made for the Mega Drive hardware could easily be ported to these systems.

During development the hardware was called "Mark V", but SEGA CEO Hayao Nakayama officially named it "Mega Drive". The name was said to represent superiority (Mega), and speed (Drive), with the then powerful Motorola 68000 processor in mind. SEGA used the name Mega Drive for the Japanese, European, Asian, Australian and Brazilian versions of the console. The North American version went by the name "SEGA Genesis" due to a trademark dispute.

Launch
The console was released in Japan as Mega Drive on October 29, 1988. SEGA announced a North American release date for the system (as SEGA Genesis) on January 9, 1989.

The European release, as the Mega Drive, was on November 30, 1990. Following on from the European success of the Master System, the Mega Drive became a very popular console in Europe. Unlike in other regions where the NES had been the dominant platform, the Master System] was the most popular console in Europe at the time. In the United Kingdom the most well known of SEGA's advertising slogans was "To be this good takes AGES, to be this good takes SEGA". Some of these advertisements employed adult humor and innuendo with sentences like "The more you play with it, the harder it gets" displayed with an illustration of the waggling of a joystick. SEGA even spent several million pounds on four or five commercials starring Peter Wingfield as Jimmy, the video game addict to use his celebrity power to help popularize the slogan. It eventually spun off a popular commercial advertising a Cyber Razor Cut. A prominent figure in the European marketing was the "SEGA Pirate", a talking one-eyed skull that starred in many TV advertisements with a generally edgy and humorous attitude. Since the Mega Drive was already two years old at the release in Europe, the many games available at launch were naturally more in numbers compared to the launches in other regions. The ports of arcade titles like Altered Beast, Golden Axe and Ghouls 'n Ghosts, available in stores at launch, provided a strong image of the console's power to deliver an arcade-like experience. Although the SEGA Genesis was not capable of arcade-exact graphics & sound, it was closer than what was possible on the NES or Master System. The arrival of Sonic the Hedgehog in 1991 was just as successful as in North America, with the new SEGA mascot becoming popular throughout the continent.

In Brazil, the Mega Drive was released by Tec Toy in 1990, only a year after the Brazilian release of the SEGA Master System. Tec Toy also ran the Internet service SEGA Meganet in Brazil as well as producing games exclusively for the Brazilian market. On December 5, 2007, Tec Toy released a portable version of Mega Drive with 20 built-in games. In India, distribution of the Mega Drive was handled by Shaw Wallace, with each products sold for 18,000 Indian rupees. SEGA entered the partnership in the northern hemisphere spring of 1995 because it wanted to circumvent an 80% import tariff. Samsung handled it in Korea. Samsung renamed the console "Super Gam*Boy", while retaining the Mega Drive logo on the system in addition to their own. It was later renamed as "Super Aladdin Boy".

Console wars
The Mega Drive initially competed against the ageing 8-bit NES, over which it had superior graphics and sound. The Mega Drive met a lukewarm reception in Japan, where the 16-bit PC Engine had already established a strong foothold by the time of the Mega Drive's launch. Despite some positive coverage from magazines Famitsu and Beep!, SEGA only managed to ship 400,000 units in the first year. In order to increase sales, SEGA released various peripherals and games, including an online banking system and answering machine called the SEGA Mega Anser. Despite this, the Mega Drive remained a distant third in Japan behind Nintendo's Super Famicom and NEC's PC-Engine throughout the 16-bit era.

For the North American market, new SEGA of America CEO Michael Katz instituted a two-part approach to build sales in that region. The first part involved a marketing campaign to challenge Nintendo head-on and emphasize the more arcade-like experience available on the Genesis, summarized by the slogans "Gotta get Genesis" and "Genesis does what Nintendon't". Since Nintendo owned the console rights to most arcade games of the time, the second part involved creating a library of instantly-recognizable titles which used the names and likenesses of celebrities and athletes such as Pat Riley Basketball, Arnold Palmer Tournament Golf, James 'Buster' Douglas Knockout Boxing, Joe Montana Football, Tommy Lasorda Baseball, Mario Lemieux Hockey and Michael Jackson's Moonwalker. Nonetheless, it had a hard time overcoming Nintendo's ubiquitous presence in the consumer's home.

In mid-1990, SEGA CEO Hayao Nakayama hired Tom Kalinske to replace Katz as CEO of SEGA of America. Although Kalinske initially knew little about the video game market, he surrounded himself with industry-savvy advisors. A believer in the razor and blades business model, he developed a four-point plan: cut the price of the console; create a US-based team to develop games targeted at the American market; continue and expand the aggressive advertising campaigns; and replace the bundled game, Altered Beast, with a new title, Sonic the Hedgehog. The Japanese board of directors initially disapproved of the plan but all four points were approved by Nakayama. Magazines praised Sonic as one of the greatest games yet made and SEGA's console finally took off as customers who had been waiting for the SNES decided to purchase a Genesis instead. Nintendo's console debuted against an established competitor, while NEC's TurboGrafx-16 failed to gain traction and NEC soon pulled out of the market.

Due to the Genesis' head start, much larger library of games, and lower price point, it was able to secure an estimated 60% of the American 16-bit console market by June 1992. SEGA's advertising continued to position the Genesis as the "cooler" console, and at one point in its campaign, it used the term "Blast Processing" (the origin of which is an obscure programming trick on the console's graphics hardware ) to suggest that the processing capabilities of the Genesis were far greater than those of the SNES. A Sony focus group found that teenage boys would not admit to owning a Super NES rather than a Genesis. Neither console could maintain a definitive lead in market share for several years, with Nintendo's share of the 16-bit machine business dipping down from 60% at the end of 1992 to 37% at the end of 1993, SEGA accounting for 55% of all 16-bit hardware sales during 1994, and Donkey Kong Country paving the way for the Super NES to win a handful of the waning years of the 16-bit generation. According to a 2014 Wedbush Securities report based on NPD sales data, the SNES ultimately outsold the Genesis in the U.S. market.[41]

In Europe the Mega Drive maintained support until 1998, where it managed to sell 8 million units, outselling all other consoles up through that time. The Mega Drive also saw success in Brazil, where it held 75% of the market share.

Videogame Rating Council
In 1993 American media began to focus on the mature content of some video games, with games like Night Trap for the SEGA CD receiving unprecedented media scrutiny. By far the most controversial title of the year, however, was Acclaim's Mortal Kombat. Parents and senators alike were outraged by the level of graphic violence depicted in the arcade version of the game. In response, Nintendo decided to replace the blood in the game with "sweat" and the arcade's gruesome "fatalities" with less violent finishing moves.

SEGA instituted America's first video game ratings system called the Videogame Rating Council (or VRC) for all their current systems. Ratings ranged from the family friendly GA rating to the adults-only ratings of MA-13, and MA-17. This let SEGA take a different approach with their release of Mortal Kombat. At face value, the blood was completely gone, not even sweat remained, and most were finishing moves toned down even more than the SNES version. However, all the arcade's blood and uncensored finishing moves could be enabled by entering the "Blood Code". Inclusion of the code let SEGA get away with the low rating of MA-13, rather than MA-17, while the SNES version shipped without a rating at all. Despite the ratings system, or perhaps because of it, the Genesis version of Mortal Kombat was well received by gaming press, as well as fans, outselling the SNES version four to one, while Nintendo was criticized for censoring the SNES version of the game. With these rating systems in place, Nintendo decided its censorship policies were no longer needed. Consequently, the SNES port of Mortal Kombat II was released uncensored.

Add-ons
In early 1991, SEGA announced the Mega CD, to be released in Japan in late 1991 and in North America (as the SEGA CD) in 1992. While this add-on did contain a faster CPU, more memory, an additional PCM sound chip, and some enhanced graphical capabilities (similar to the SNES's mode 7) compared to the Mega Drive itself, the main focus of the device was to expand the size of games. Cartridges of the day typically contained 8 to 16 megabits of data, while a CD-ROM could hold 640 megabytes (5120 megabits). While it became known for several games, including Sonic CD and Night Trap, the expansion only sold 6 million units worldwide.

At June 1994's Consumer Electronics Show, SEGA presented the 32X, a new add-on peripheral for the Genesis that the company billed as "the poor man's 32-bit machine". The 32X was originally conceived by SEGA of Japan as a fully compatible Mega Drive based console with enhanced color capabilities. SEGA of America R&D head Joe Miller convinced SEGA of Japan to convert it into an add-on to the existing Genesis. Although this add-on contained two 32-bit CPUs, it failed to attract either developers or consumers as the superior Saturn had already been announced for release the next year. Originally released in November 1994 (after the release of the SEGA Saturn in Japan) for US$159, SEGA dropped the price to $99 after only a few months and ultimately cleared the remaining inventory at $19.95. Although initial sales were good, thanks mostly to Doom and Star Wars Arcade, SEGA was only able to move 665,000 units worldwide by the end of fiscal year 1994.

In 1996, both the Mega CD and 32X were discontinued.

32-bit era and beyond
By the end of 1995, SEGA was supporting five different consoles and two add-ons: SEGA Saturn, Mega Drive, Game Gear, Pico, Mega CD / SEGA CD, 32X and Master System in PAL and some South American (predominantly Brazilian) markets. In Japan the Mega Drive had never been successful and the Saturn was beating Sony's PlayStation, so SEGA of Japan CEO Hayao Nakayama decided to force SEGA of America to focus on the Saturn, executing a surprise early launch of the Saturn in early summer of 1995. While this made perfect sense for the Japanese market, it was disastrous in North America: the market for Genesis games was much larger than for the Saturn but SEGA was left without the inventory or software to meet demand. In comparison, Nintendo concentrated on the 16-bit market, and as a result, Nintendo took in 42 percent of the video game market dollar share with no next gen system.ref name=sales95> While SEGA was still able to capture 43 percent of the dollar share of the US video game market as a whole, Nakayama's decision undercut the SEGA of America executives; CEO Tom Kalinske, who oversaw the rise of the Genesis in 1991, grew uninterested in the business and resigned in mid 1996.

The Mega Drive was supported until 1998 in Europe, when SEGA announced it was dropping support for it. It was discontinued along with its predecessor, the long-lived SEGA Master System, to allow SEGA to concentrate on its newer console, the Saturn.

In 1998, SEGA licensed the Genesis to Majesco in North America so that it could re-release the console. Majesco began re-selling millions of formerly unsold cartridges at a budget price together with 150,000 units of the second model of the Genesis, until it later released the SEGA Genesis 3. In 1998 Frogger became the last commercially licensed game to be released in North America. Majesco released the Genesis 3 at $50, a price which Nintendo matched with their newly-redesigned Super NES. Majesco then dropped the price of the Genesis 3 to US $40 and again to US $30, with Nintendo matching them dollar-for-dollar every step of the way. Software prices for both systems remained stagnant, ranging anywhere from US $10 to US $25 per title. By this time, 16-bit sales only accounted for 10% of the total U.S. console market, but it was a brisk and fiercely fought share. Majesco would wind up selling between 1 and 2 million Genesis 3 consoles, along with 10 million or so Genesis cartridges for fiscal year 1998. In comparison, Nintendo would only sell 1 million SNES consoles and 6 million SNES cartridges.

Emulation
Like many other game consoles, the Mega Drive has a strong following among gaming enthusiasts and fans, even following its decline in the marketplace. The console has enjoyed continued popularity in the second-hand market and through emulation projects.

The first known Mega Drive emulator was called "Megadrive", and was released in 1994. This emulator was only capable of playing Sonic the Hedgehog without sound, and had numerous errors. In 1996, GenEM became the first fully functional Mega Drive emulator to be released.

In 1997, former Genesis developer Steve Snake began work on a new emulation project KGEN, that would eventually be known as Kega Fusion, with the goal of perfect emulation. SEGA officially commissioned Snake in the following year to create a Microsoft Windows-compatible version that could be used to market some classic Mega Drive games in the "SEGA Smash Pack".

Another emulator, Gens, began development in 1999. This project achieved widespread popularity in the emulation community and inspired many derivative projects. However, the project ceased development in 2006 and never reached the same level of accuracy as Kega Fusion. Both emulators feature online play and can record videos of gaming sessions. A multi-system emulator, called RetroCopy, started emulating Mega Drive from version 0.666 (released Dec 12, 2009), and was the first emulator to emulate the Mega Drive VDP at a cycle accurate level.

Emulation of the Mega Drive is also available on home consoles and handheld units such as SEGA's Dreamcast; Nintendo's GameCube, Wii, and DS; GamePark Holdings' GP2X; Sony's PlayStation 2 and PlayStation Portable and Microsoft's Xbox and Xbox 360. Emulators have also been produced for smart phones, such as Apple Inc.'s iPhone as well as various PDAs.

In 2004, a trend emerged toward plug-and-play TV games and Radica Games released a licensed, self-contained, version of the Mega Drive in both North America (as the Play TV Legends SEGA Genesis) and Europe (as the Mega Drive 6-in-1 Plug 'n' Play). It contains six popular games in a small control box with a permanently connected control pad. It does not have a cartridge slot and thus is a dedicated console.

The GameTap subscription gaming service included a Mega Drive emulator and had several dozen licensed Mega Drive games in its catalog. These games have since been removed after the sale of Gametap to Metaboli. The Console Classix subscription gaming service also includes an emulator and has several hundred Mega Drive games in its catalog.

In recent years, some Mega Drive games have been successfully emulated and sold commercially on many home consoles with digital distribution platforms, such as the PlayStation 3, Wii, Wii U, Nintendo 2DS, and Nintendo 3DS. Steam also has several Master System and Mega Drive games available.

CPU and memory
The Mega Drive's CPU is a 16/32-bit Motorola 68000. The maximum addressable memory is 16 MB from the ROM ($00000000-00400000 - 4 MB), to the RAM ($00FF0000-00FFFFFF - 64 KB). The 68000 runs at 7.61 MHz in PAL consoles, 7.67 MHz in NTSC consoles. The Mega Drive also includes a Zilog Z80, which serves as secondary processor along with allowing complete Master System compatibility with only a passive adapter. The initial Mega Drive models used a Hitachi-made HD68HC000, while the Mega Drive 2 and later models used a Motorola MC68HC000, both fabricated in CMOS.

There is 64 KB of Main RAM, as part of the 68000 address space. Also present is 64 KB of Video RAM, for exclusive use and access by the VDP (Video Display Processor). The Z80 has 8 kilobytes of RAM for use as program RAM, which is also mapped into the 68000's address space. The Z80 can also access 32 kilobytes of the 68000s memory using bank-switching, which can be used as a sound bank while in use as an audio controller.

There is also 2 KB of Boot ROM, which is also known as the "Trademark Security System" (TMSS). When the console is started, it checks the game for certain code given to licensed developers. Unlicensed games without the code are thus locked out, but if a game is properly licensed, the ROM will display "Produced by or under license from SEGA Enterprises Ltd.". Also, as a hardware-feature, with later versions of the Trademark Security System "SEGA" must be written into an area of I/O memory (A$14000) in order to turn on the VDP. The TMSS was the subject of the legal case SEGA v. Accolade.

Audio and video
There are two primary sound chips which can both be controlled by the Z80 or the 68000; the Yamaha YM2612 FM synth chip and the Texas Instruments SN76489 PSG chip. The YM2612 is a stripped-down version of the YM2608, which is an upgraded version of the prolific Yamaha YM2203, used in many gaming machines throughout the 1980s and early 1990s. The Yamaha uses six FM channels with four operators each, and its clock speed is the same as that of the main CPU.

Stereo sound is output only through the headphone jack on model 1 systems and through AV out on model 2 systems along with mono signal. Changes in the mixing circuit of late model 1 revisions, and all model 2's resulted in the hardware producing more distorted sound output than earlier models that bore the "High Definition Graphics" logo.

The Mega Drive uses the Yamaha YM7101 for graphics generation and sprite control. The YM7101 is based on the Master System's VDP (or Video Display Processor), which in turn is derived from the Texas Instruments TMS9918. The YM7101 includes additional display modes and capabilities along with the Master System VDP's original display modes (minus the original TMS9918 modes). Images can be output at 256 pixels (32 tiles) or 320 pixels (40 tiles) across and 224 scanlines (28 tiles) or 240 scanlines (30 tiles) down. The 240-line resolutions are only used on 50 Hz (i.e. PAL) displays, as the extra lines end up in the overscan of a 60 Hz (NTSC) signal.

NTSC games use the 224-line resolution to free up more vertical blanking time to send more updates to the VDP. Colors are chosen from a total of 512 possible colors, 3 bits per color channel; some games used a small amount of flicker to simulate more colors. Graphics consist of up to 80 sprites on screen and three background planes (Window, ScrollA, ScrollB), two of which (ScrollA and Window) share the same screen space. Palettes are stored in color RAM (CRAM) and consist of 16 colors each for a total of 64 colors.

Inputs and outputs
On the front of the console are two controller input ports, which use 9-pin male D-subminiature connectors. On the rear of all first-model Japanese Mega Drive units and on early American Genesis and PAL (European, Australasian and Asian) Mega Drive units is the EXT input port; a DE-9F (9-pin female D-connector) that was used with the Meganet modem peripheral, released only in Japan. The power input varies depending on the model - a model 1 uses a 2.1 mm barrel connector with a negative tip, and requires 9-10 volts DC at 1.2 A. The model 2 uses a EIAJ-03 connector with a positive tip, and requires 9-10 volts DC at 0.85 A. There is also an Expansion input port which is an Edge connector on the bottom right hand side of the console. It is used almost exclusively for connection for the Mega-CD/SEGA CD, though it was also used for the SEGA Genesis 6 Cart Demo Unit (DS-16) in stores. This port is not present on the Genesis 3 model.

The console's A/V output consists of a DIN connector with composite video, RGB video and audio outputs. The Mega Drive and the first model Genesis have an 8-pin DIN socket (same as SEGA Master System) which supports mono audio only, while the Mega Drive 2, Multi-Mega/CDX and other models have a 9-pin mini-DIN connector with both mono and stereo audio. Stereo audio for the Mega Drive and the first model Genesis were supplied by the headphone jack, which is not present on later models. Original model European and Asian Mega Drives and the North American Genesis model also include a built in RF modulator, which outputs via an RCA jack on the rear of the console; other models must use an external RF modulator for RF video/audio.

Master System compatibility
One of the key design features of the console is its backwards compatibility with SEGA's previous console, the Master System. The 16-bit design is based upon the 8-bit design, albeit enhanced and extended in many areas. In order to achieve backwards compatibility, the Master System's central processor and sound chip (the Zilog Z80 and SN76489 respectively) are included as coprocessors in the Mega Drive, and the Mega Drive's Video Display Processor (VDP) is capable of the Master System's VDP mode 4, though it cannot run in modes 0, 1, 2, or 3 (so the Mega Drive is not compatible with SG-1000 software or Master System software which uses these modes).

As the cartridge slot is of a different shape, SEGA released the Power Base Converter, a separate device that sits between a Master System cartridge and the Mega Drive's cartridge slot. The Power Base Converter does not contain any Master System components, instead functioning as a pass-through device, and consisting almost entirely of passive circuitry. The converter contains a top slot for cartridge-based games along with a front slot for card-based games, as well as the 3D glasses adapter. When a Master System game is inserted, the system puts the Z80 in control, leaving the Mega Drive's main 68000 processor idle. The Power Base Converter had inferior capacitors however, meaning that after a few years use, the system may suffer from glitchy play; to rectify this the user must remove the capacitors from the board or replace them.

In Japan the device is known as the "Mega Adapter" (メガアダプタ). The Mega Adapter is built for the Japanese Mega Drive cartridge slot, so it does not fit into the European Mega Drive and North American Genesis cartridge slots, like Japanese Mega Drive cartridges. It also has the Master System cartridge slot changed to the SEGA Mark III/Japanese Master System pinout. Because of the Genesis VDP limitations listed before, it does not run SG-1000/SC-3000 games or Master System games that use the SG-1000 video modes. The Mega Adapter does not have the Yamaha YM2413 FM chip that enhances the sound of certain games. The PAL variant is called the "Master System Converter" in Europe.

The Power Base Converter is not fully compatible with the redesigned Mega Drive 2. A second version, the "Master System Converter II", was released to address this problem. This second version adapter was produced in a far smaller quantity, lacks the slot for card-based games, and was only released in Europe.

The only Master System game which does not work with this device is F-16 Fighting Falcon. It was originally thought that the game card had more pins than the adapter could interface with, but it is actually the compatibility mode of the Mega Drive/Genesis that is responsible for the game not working, not the Power Base Converter itself. This is because, as previously said, the Genesis can only run in VDP mode 4 and the game ran in a different VDP mode.

Some Master System games (such as Shanghai and Alien Syndrome) are incompatible with the Genesis control pad. However, it is possible to correct this by modifying the control pad, or by using a Master System control pad instead. As it has the same connection port, the Master System pad can be plugged directly into Mega Drive controller ports without any kind of adapter.