Presentation :

The Sega Genesis, known as Mega Drive in most regions outside North America, is a 16-bit video game console which was developed and sold by Sega Enterprises, Ltd. The Genesis is Sega's third console and the successor to the Master System. Sega first released the console as the Mega Drive in Japan in 1988, followed by a North American debut under the Genesis moniker in 1989. In 1990, the console was released as the Mega Drive by Virgin Mastertronic in Europe, by Ozisoft in Australasia, and by Tec Toy in Brazil. In South Korea it was distributed by Samsung and was first known as the Super Gam*Boy and later as the Super Aladdin Boy.
Designed by an R&D team supervised by Masami Ishikawa, the Genesis hardware was adapted from Sega's System 16 arcade board, centered around a Motorola 68000 processor as a primary CPU and a Zilog Z80 as a secondary processor. The system supports a library of over 900 games created both by Sega and a wide array of third-party publishers and delivered on ROM-based cartridges. It can also play the complete library of Master System games when the separately sold Power Base Converter is installed. The Genesis also benefited from numerous peripherals and several network services, as well as multiple first-party and third-party variations of the console that focused on extending its functionality.
In Japan, the Mega Drive did not fare well against its two main competitors, Nintendo's Super Famicom and NEC's PC Engine. However, it achieved considerable success in North America and in Europe, capturing the majority of the 16-bit market share in several territories including the United States and the United Kingdom. Contributing to its success were its library of arcade game ports, the popularity of the Genesis-exclusive Sonic the Hedgehog series, several popular sports game franchises, and aggressive youth marketing that positioned the system as the cool console for adolescents. Though Sega dominated the market in North America and Europe for several years, the release of the Super Nintendo Entertainment System resulted in a fierce battle for market share in those territories that has often been termed a "console war" by journalists and historians.
As this contest drew increasing attention to the video game industry among the general public, the Genesis and several of its highest-profile games attracted significant legal scrutiny on matters involving reverse engineering and video game violence. Controversy surrounding violent titles like Night Trap and Mortal Kombat led Sega to create the Videogame Rating Council, a predecessor to the Entertainment Software Ratings Board.
By the end of 1994, when a new generation of 32-bit consoles rendered the system technologically obsolete, the Genesis had sold 29 million units worldwide, and by the end of its life Sega had sold an estimated 40 million units. The console and its games continue to be popular among fans, collectors, video game music fans, and emulation enthusiasts. Licensed third party re-releases of the console are still being produced, and several indie game developers continue to produce games for it. Many games have also been re-released in compilations for newer consoles and offered for download on various online services, such as Wii Virtual Console, Xbox Live Arcade, PlayStation Network, and Steam.

History :

In the early 1980s, Sega Enterprises, Inc., then a subsidiary of Gulf & Western, was one of the top five arcade game manufacturers active in the United States, as company revenues rose to $214 million. A downturn in the arcade business starting in 1982 seriously hurt the company, leading Gulf & Western to sell its North American arcade manufacturing organization and the licensing rights for its arcade games to Bally Manufacturing. The company retained Sega's North American R&D operation, as well as its Japanese subsidiary, Sega of Japan. With its arcade business in decline, Gulf & Western executives turned to Sega of Japan's president, Hayao Nakayama, for advice on how to proceed. Nakayama advocated that the company leverage its hardware expertise gained through years working in the arcade industry to move into the home console market in Japan, which was in its infancy at the time. Nakayama received permission to proceed with this project, leading to the release of Sega's first home video game system, the SG-1000, in July 1983. The SG-1000 was not successful, and was replaced by the Sega Mark III within two years. In the meantime, Gulf & Western began to divest itself of its non-core businesses after the death of company founder Charles Bludhorn, so Nakayama and former Sega CEO David Rosen arranged a management buyout of the Japanese subsidiary in 1984 with financial backing from CSK Corporation, a prominent Japanese software company. Nakayama was then installed as CEO of the new Sega Enterprises, Ltd.
In 1986, Sega redesigned the Mark III for release in North America as the Sega Master System. This was followed by a European release the next year. Although the Master System was a success in Europe, and later also Brazil, it failed to ignite significant interest in the Japanese or North American markets, which, by the mid-to-late 1980s, were both dominated by Nintendo. With Sega continuing to have difficulty penetrating the home market, Sega's console R&D team, led by Masami Ishikawa, began work on a successor to the Master System almost immediately after that console launched. In 1987, Sega faced another threat to its console business when Japanese computer giant NEC released the PC Engine amid great publicity. To remain competitive against the two more established consumer electronics companies, Ishikawa and his team decided they needed to incorporate a 16-bit microprocessor into their new system to make an impact in the marketplace and once again turned to Sega's strengths in the arcade industry to adapt the successful Sega System 16 arcade board into a home console architecture. First announced in June 1988 in Beep!, a Japanese gaming magazine, the developing console was referred to as the "Mark V", but Sega management felt the need for a stronger name. After reviewing over 300 proposals, the company settled on "Mega Drive". In North America, the name of the console was changed to "Genesis". The reason for this change is not known, but it may have been due to a trademark dispute.

Technical Specification :

• Main Processor : Motorola 68000 clocked 7,67 MHz (NTSC)
• Co Processor : Zilog Z80 clocked 3,58 MHz (NTSC)
• Memory : 72 kB

• Video processor  : VDP
• Vidéo memory : 64 kB
• Vidéo ability :
  • Resolution : 320×224 pixels and 320×448,
  • 16 colors per plan in 512
  • 80 sprites with 32×32 pixels max

• Sound processor :
  • Yamaha YM2612 FM clocked 7,67 MHz (NTSC)
  • SN76489 PSG clocked 3,58 MHz (NTSC)
• Sound ability : 6 channel FM, 1 channel PCM, 3 channel PSG