The Sega Genesis as a 16-bit video game console released by Sega in Japan (1988), Europe (1990) and most of the rest of the world.
Although the Sega Master System had proved a success in Brazil and Europe, 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 with 95% and 92% market shares respectively. Hoping to dramatically increase their share, Sega set about creating a new machine that would be at least as powerful as the then most impressive hardware on the market - the 16-bit Commodore Amiga and Atari ST home computers.
Since the System 16 made by Sega was very popular, Hayao Nakayama, Sega's CEO at the time, decided to make their new home system utilize a 16-bit architecture. The final design was ported to the arcade, and eventually 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.
The first name Sega considered for their console was the MK-1601, but they ultimately decided to call it the "Sega Mega Drive". "Mega" had the connotation of superiority, and "Drive" had the connotation of speed and power. 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 "Genesis" due to a trademark dispute, while the South Korean versions were called Super Gam*Boy (?????) and Super Aladdin Boy (transliterated from ???????; this was the Korean version of Mega Drive 2). The Korean-market consoles were licensed and distributed by Samsung Electronics.
North American release and further development
In 1987, Sega announced a North American release date for the system of January 9, 1989, making it the second console to feature a 16-bit CPU (the first one being the Mattel Intellivision) and the first to feature single-instruction 32-bit arithmetic. Sega was not able to meet the initial release date and U.S. sales began on August 14, 1989 in New York City and Los Angeles with a suggested retail price of $200 at launch. The Genesis was released in the rest of North America on September 15 of the same year with the price reduced slightly to $190.
The Genesis initially competed against the 8-bit NES, over which it had superior graphics and sound. Nonetheless, it had a hard time overcoming Nintendo's ubiquitous presence in the consumer's home and the huge catalog of popular games already available for it. In an attempt to build themselves a significant consumer base, Sega decided to focus on slightly older buyers, especially young men in their late teens and early 20s who would have more disposable income and who were anxious for more "grown-up" titles with more mature content and/or more in-depth game play. As such, Sega released titles such as Altered Beast and the Phantasy Star series. Although the NES and Nintendo's impending SNES were still threats to Sega's market share, they had forced the theoretically competitive TurboGrafx 16 system into relative obscurity, thanks in part to NEC's poor North American marketing campaign.
By 1992, Sega was enjoying a stronghold on the market, holding a 55% market share in North America. Faced with a slight recession in sales and a brief loss of market share to the SNES, Sega again looked to Sonic to rejuvenate sales. The release of the highly anticipated Sonic the Hedgehog 2, coinciding with an aggressive ad campaign that took shots at Nintendo, fueled Genesis sales a while longer and boosted Sega's market share percentage back up, to an astounding 65%.
Less than a year later, in 1993, Sega released a redesigned version of the console at a newly reduced price. By consolidating the internal chipset onto a smaller, unified motherboard, Sega was able to both physically reduce the system's size and bring down production costs by simplifying the assembly procedure and reducing the number of integrated circuits required for each unit.
Aside from the release of the Sega CD and 32X add-ons for the Genesis/Mega Drive, Sega's last big announcement came in the form of a partnership with Time Warner in the U.S. to offer a subscription-based service called Sega Channel, which would allow subscribers to "download" games on a month-by-month basis.
Decline in market share
The failures of the Sega CD and 32X, a lack of effective advertising, and disputes between Sega of America and Sega of Japan had taken their toll on the company. By 1994, Sega's market share had dropped from 65% to 35%, and the official announcements of newer, more powerful consoles, such as the Saturn, Playstation, and N64 signaled that the 16-bit era was drawing to a close. Interest in the Genesis suffered greatly as a result, compounding its already falling sales. In 1996, less than a year after the debut of their Saturn console, Sega quickly brought their participation in the 16-bit era to an end by discontinuing production of the Genesis and its associated accessories. This obviously angered consumers around the world who had bought the Sega CD and 32X attachments only to see Sega abandon all support. This can, at least in slight, be seen as a contributing factor to the downfall of Sega as a console manufacturer. (see Video game market).
In recent years, there has been something of a revival of interest in the Mega Drive/Genesis, led largely by the grey market trade in both unlicensed cartridges (for instance, the biblically themed output of Wisdom Tree) and dumped ROMs, which are played through emulators such as Kega Fusion, GENS, or Genecyst. There is also a trend towards home programming, using the PC-based SGCC.
In the 2000s, there came a trend toward plug-and-play TV games, and Radica has released licensed, self-contained versions of the Sega Mega Drive/Genesis in both North America (as the Play TV Legends Sega Genesis) and Europe (as the Sega Mega Drive 6-in-1 Plug 'n' Play), which contain six popular games in a small box and control pad. It does not have a cartridge slot, and thus is a dedicated console. However, Benjamin Heckendorn, of Atari portablizing fame, has proven that it is possible to connect a cartridge slot with some soldering.
The GameTap subscription gaming service includes a Genesis emulator, and has several dozen licensed Genesis games in its catalog.
On March 23, 2006, it was announced at the Game Developers Conference in San Jose California that Nintendo will offer Sega Mega Drive/Genesis game ports on the Wii home console. However it is not yet clear whether this includes all titles in the console's back catalogue. The announcement also stated that PC Engine games would be available for download to the virtual console.
On May 22, 2006 Super Fighter Team released the Beggar Prince, a game translated from a 1996 Chinese original. It is the first commercial Sega Megadrive game since 1998 in the North American market. It was released worldwide.
Variations of the Mega Drive/Sega Genesis
Main article: Variations of the Sega Mega Drive
During its lifespan, the Mega Drive and Genesis quite possibly received more officially licensed variations than any other console. While only one major design revision of the console was created during its lifespan, each region has its own peculiarities and unique items, while other variations were exercises in reducing costs (such as the removal of the little-used 9-pin EXT. port) or expanding the capabilities of the Mega Drive/Genesis.
Main processor: 16-bit Motorola 68000 (or equivalent)
* Runs at 7.61 MHz in PAL consoles, 7.67 MHz in NTSC consoles.
* Some systems contained clones of the Motorola 68000 manufactured by Hitachi and Signetics.
* Signetics 68K only found in early revisions as this CPU is known to be inefficient.
Secondary processor: 8-bit Zilog Z80 (or equivalent)
* Runs at 3.55 MHz in PAL consoles, 3.58 MHz in NTSC consoles
* Used as main CPU in Master System compatibility mode.
Boot ROM: 2 KB
* Known as the "Trademark Security System" (TMSS)
* When console is started, it checks the game for certain code given to licensed developers
* Unlicensed games without the code are thus locked out
* If a game is properly licensed, the ROM will display "Produced by or under license from Sega Enterprises Ltd."
* Boot ROM is not present on earlier versions of the Mega Drive and Genesis
* Some earlier games not designed for the TMSS may not work in later consoles
Main RAM: 64 KBytes
* Part of M68000 address space
Video RAM: 64 KBytes
* Cannot be accessed directly by CPU, must be read and written via VDP (Video Display Processor - see below)
Secondary RAM: 8 KBytes
* Part of Z80 address space
* Used as main RAM in Master System compatibility mode
Audio RAM: 8 KBytes
Cartridge memory area: up to 4 MBytes (32 Megabits)
* Part of M68000 address space
* Game cartridges larger than 4 MBytes must use bank switching
The Mega Drive has a dedicated VDP (Video Display Processor) for playfield and sprite control. This is an improved version of the Sega Master System VDP, which in turn is derived from the Texas Instruments TMS9918. It contains both mode 4 (for Master System compatibility) and mode 5 (for native Genesis games). However, Master System programs can switch the VDP into mode 5 and make use of advanced VDP features. This page only discusses mode 5 capabilities.
Planes: 4 (2 scrolling playfields, 1 sprite plane, 1 'window' plane), per-tile priority
Sprites: Up to 64 (32H)/80 (40H) on-screen, 16/20 per line, 256/320 pixels per line, per-sprite priority
Palette: 512 colors (1536 using shadow/highlight mode)
On-screen colors: 64 × 9-bit words of color RAM, 4 lines of 15 colors plus transparent, allowing 61 on-screen colors (up to 1536 via raster effects and shadow/highlight)
Screen resolution: 256x224 (32Hx28V), 320x224 (40Hx28V), 256x240 (32Hx30V, PAL only), 320x240 (40Hx30V, PAL only)
* Interlace mode 1 provides no increase in resolution, but still generates a true interlaced signal
* Interlace mode 2 can provide double the vertical resolution (i.e. 320×448 for NTSC, 320x480 for PAL). Used in Sonic 2 for two-player split screen
Scroll size: Width and height independently set to 32, 64, or 128 cells as VRAM allows
Main sound chip: Yamaha YM2612
* Six FM channels, four operators each; channel 6 can be used for PCM data or as a regular channel
* Programmable low-frequency oscillator and stereo panning
Secondary sound chip: Texas Instruments SN76489 compatible device built into VDP.
* Four-channel PSG (Programmable Sound Generator)
* Three square wave channels, one white noise channel
* Programmable tone/noise and attenuation
* Used for Master System compatibility mode as well as to supplement FM
* Different random noise generation compared to a real SN76489/SN76489A chip
Inputs and outputs
RF output: RCA jack connects to TV antenna input
* Exists on original model European and Asian Mega Drive and North American Genesis only
* Other models must use external RF modulator which plugs into A/V output
A/V output: DIN connector with composite video, RGB video, and audio outputs
* Mega Drive and the first model Genesis have an 8-pin DIN socket (same as Sega Master System) which supports mono audio only
* Mega Drive 2, Multimega, and other models have a 9-pin mini DIN socket with both mono and stereo audio
Power input: positive tip barrel connector. Requires 9-10 volts DC, 0.85-1.2 A depending on model
Headphone output: Amplified 3.5-mm stereo jack on front of console with volume control
* Exists only on original model Mega Drive and Genesis units
* Provides stereo audio on models which have the mono 8-pin DIN A/V output
* Also suitable for passive speakers
* Can be used for mixing audio from the SegaCD
"EXT" port: DE-9F (9-pin female D-connector) on back of console
* Used with the Meganet modem peripheral, released only in Japan
* Exists on all first-model Japanese and Asian Mega Drive units, and on early American Genesis and European Mega Drive units
* May have been used for game selection on arcade adaptations of the Mega Drive / Genesis console
Control pad inputs: two DE-9M (9-pin male D-connectors) on front of console
Expansion port: Edge connector on bottom right hand side of console
* used almost exclusively for Sega Mega-CD connection
* not present on Genesis 3 model
* also used for the Sega Genesis 6 Cart Demo Unit (DS-16) in stores.