Sega Mega Drive

From Academic Kids

(Redirected from Megadrive)
Missing image
Original Sega Mega Drive (PAL version)

Sega Mega Drive (Japanese: メガドライブ Mega Doraibu) is a 16-bit video game console released by Sega in 1988.

For information on the North American version of the console, see: Sega Genesis



Sixteen-bit personal machines like the Amiga and the Atari ST, as well as 16-bit arcade machines, were outpacing the eight-bit videogame consoles. Another problem was that Nintendo had 95% of the North American videogame market and 92% of the Japanese market; Nintendo's eight-bit and 16-bit machines were not that successful in Europe. Sega knew the Sega Master System was not going to make it in North America and Japan, so they decided to make a new console.

Since the System 16 arcade games that Sega was making got very popular, Hayou Nakayama, then Sega's CEO, decided to make their new system a 16-bit one. The final design worked great, and so they used three new arcade boards, being the Megatech, Megaplay, and the System C. Any of the games made for these systems could work on their new console.

The first name Sega thought of for their console was the MK-1601, but Sega decided to use "Sega Mega Drive" as the name. "Mega" had the connotation of superiority, and "Drive" had the connotation of speed and power. They went with that name for the Japanese, European, Asian, Australian and Brazilian versions of the console.

When NEC released the PC Engine in Japan on October 30, 1987, it posed a threat to Nintendo. While NEC overall did not achieve total dominace of the Japanese market, its earlier success meant the Mega Drive initially had a slower adoption than NEC's system did.

The Sega Mega Drive was released in Japan in October 29, 1988 for 21,000. The European release was on November 30, 1990 in the United Kingdom, priced at 190.

Unlike in the United States, the Japanese Mega Drive was overshadowed by the Sega Saturn in its country. Just like its North American counterpart, however, the European Mega Drive did better than the Sega Saturn in that locale. The console was shipped with the classic Sonic the Hedgehog game at a reduced price.

The Mega Drive initially competed against the PC Engine system in Japan and the Nintendo Entertainment System in Europe.

The Japanese audience was split between the Famicom and PC Engine. When the Mega Drive entered the market, its lack of a CD drive and significantly better graphics than the established PC Engine held it back until the debut of the Super Famicom. The Super Famicom went on to lead the market in that country. The Mega Drive ended up doing worse than the PC Engine did, despite its technical superiority over the PC Engine and the Famicom.

The European NES market was very confusing, with different companies handling the NES in different markets. The Sega Master System had no problem excelling in Europe. The European Mega Drive outsold all other consoles, including the Sega Saturn. The Mega Drive was supported in that locale until 1998.

The Mega Drive counterpart in Europe eventually competed with Nintendo's Super Nintendo Entertainment System, while the Japanese Mega Drive competed with the Super Famicom, the Japanese version of the SNES.

Three add-on components had been released for the Mega Drive in Japan, and two were released for the Mega Drive in Europe and Australia. The Sega Meganet modem was only released in Japan. The Sega Mega-CD was released for all versions of the Mega Drive worldwide. The Sega Super 32X came to the Japanese while the Europeans and the Australians got the Sega Mega Drive 32X.

Missing image
Sega Mega Drive II European version

The Sega Mega Drive 2 was introduced in 1993. The redesign reduced cost and size by consolidating chips and removing the built-in headphone jack. Like later versions of the Mega Drive 1, it included a "copyright check" in the firmware (which broke compatibility with some older unlicensed games). A new version of the Sega Mega-CD, the Sega Mega-CD 2, was made to accommodate the shape of the redesigned console.

The Mega Drive 2 had a number of sub-revisions, the very last of which consolidated most of the chips (including the Z80 and M68000 CPUs) into one large custom chip. The original console itself went through innumerable revisions, unknown to most users save the ones who owned one of the very first consoles, which had trouble playing a few of the newer games.

One unlikely market that the Mega Drive excelled in was Brazil. Brazil was also where the Sega Master System lived its absolute final days, to 1998. The Mega Drive also held over until 1998 in that area. Tec Toy was Sega's Brazilian distributor and had success with both of those consoles. Sega had 75% of the Brazilian market.

The Mega Drive was designed from the outset to be backwards compatible with the Sega Master System/Mark III. This was achieved with a plug-in converter known as the Mega Adapter in Japan, the Power Base Converter in North America, and the Master System Converter in Europe. The device sits on top of the console and fits into the cartridge port; it takes both cartridges and cards, and includes a pause button on the front. Almost all Master System games can be played, but a few (e.g. F-16 Fighter) are incompatible due to hardware differences. Master System accessories, including the Light Phaser and 3D Glasses, can also be used with the converter.

A newer Master System Converter for the Mega Drive 2 was released in Europe, but (as with the Master System 2) the card port was removed, breaking compatibility with card-based games and the 3D Glasses. The Mega Master was a third party Master System converter distributed by Fire and Datel in the United Kingdom. It looked like the official Mega Drive 2 Converter, but the pause button was on the side as a toggle switch.

Although Sega had talks about a Game Gear Converter, tentatively named the Mega Game Gear, Sega never made one.

Versions of the Sega Mega Drive

Missing image
Two versions of the Mega Drive controller: three-button (top) and six-button (bottom) pads
Missing image
European (left) and American (right) boxes
  • Sega Mega Drive 1 in Japan
    • Japanese-language settings
    • Headphone jack
    • AUX Port
    • Supports Sega Mega-CD and Sega Super 32X
    • Had a cartridge lock
    • Gloss Black Finish
    • On the circular molding is the text "High Grade Multi Purpose Intelligent Terminal". At the bottom of the circle is a purple square section.
    • Cooling vents are located on the left side.
    • "Sega Mega Drive" is printed in white on the lower right of the console.
    • The reset button and start button on the joypad are blue.
  • Sega Mega Drive 1 in Europe, Australia, and New Zealand
    • Converted to display PAL 50-Hz signal
    • English-language settings
    • Cannot play Japanese Mega Drive games due to shape of cartridge and console (though adapters were sold to play Japanese games in the European model).
    • Cartridge lock removed
    • The text "High Definition Graphics Stereo Sound" located behind cartridge port (only found on earlier models).
    • The reset button and the start button are white.
  • Sega Mega Drive 1 in Asia (variant to European Mega Drive and often mistaken for a Japanese Mega Drive)
    • No text printed around circle
    • Larger "16-Bit" logo used
    • "Start" and "Reset" button are blue
    • Identical to European Mega Drive with PAL output
    • Used Japanese Mega Drive logo and packaging similar to the Japanese version
    • Games packaged the same as European with the same labelling, however the cartridges are shaped like Japanese Mega Drive games.
  • Sega Mega Drive 2 in Japan
    • New squared shape
    • No headphone jack
    • one Custom multi output for picture and sound
    • Red Coloured flaps on Cartridge Port
    • The text "High Grade Multi Purpose Intelligent Terminal" located behind cartridge port.
    • Packaged with six-button controller standard.
    • No power LED
  • Sega Mega Drive 2 in Europe
    • New squared shape
    • No headphone jack
    • AV Port switched to one Custom multi output for picture and sound (previously, only Mono sound was used, as the Stereo Sound came to the headphone jack)
    • Push Button Power Switch
    • Power port smaller, different AC Adapter used
    • RF Out port removed
    • Auto-switching RF Lead Included
  • Wondermega (named X'eye in North America) - A combined Mega Drive and Mega-CD sold by Victor (known as JVC outside Japan) - Never released in Europe
    • Improved sound capabilities
    • MIDI Port
    • 2 Microphone Inputs
    • S-video out
    • Packaged with a CD called Game Garden that had Flicky a (quiz game) and Pyramid (a puzzle game.) The CD is compatible with CDG (CD and Graphics) enabled CD Players.
    • Later Japanese pack had a platform game called 'Wonderdog' by Core.
    • Supported the "Wonder CD" pheripheral that allows someone to create music and connect to MIDI-enabled devices.
    • Supported a music keyboard called the "Piano Player" that allowed you to create music and learn to use the keyboard.
    • Later given a redesign with a softer, more curved look. Some of the extra features were removed, and the joypads were remodeled infra red joypads.
  • Sega Multi-Mega (named CDX in North America) - An integrated Mega Drive and Mega-CD console with portable CD Player abilities, aimed at the more affluent market. The British release sold at 350.
    • No built-in screen.
    • Could double as a portable CD player. CD control buttons (play, stop, etc.) are on the front of the console. A backlit LCD provided the track number. An extra line-out port was provided for stereo equipment.
    • Charged by 2 AA batteries that can only run the CD player. The unit must be powered by a mains adapter to play video games.
  • Mega-Tech - An arcade machine that featured 10 interchangeable Mega Drive or Master System games in an arcade cabinet.
    • First released in 1989 with some of the best titles at the time, such as Thunderforce II, Altered Beast, Tetris, Last Battle, Space Harrier II, and Golden Axe.
    • Games could be changed at any time, and more titles, such as Sonic the Hedgehog, were made available. The games were identical to their original counterparts, and the cheats also worked.
    • Games were supplied by a Japanese-shaped Mega Drive cart, although slightly heavier. The labels were silver and red and only had "Mega-Tech" printed on them. These carts are not compatible with a regular Mega Drive/Genesis due to the extra information on them stored to run the second monitor, a different length edge connector, number of pins, pinouts, and spacing.
    • A second, smaller nine-inch monitor is located at the top of the cabinet. It displayed instructions for each of the games. The user pays to play for a certain length of time. When time was starting to run out, the screen flashed green to notify the user that additional credits are needed should he or she want to play more of that game.
  • Mega Play - Another arcade system like the Mega-Tech, but this only had 4 cartridge slots and could not play Master System games.
    • Cartridges were Japanese Mega Drive in shape, but incompatible with consumer Mega Drive or Mega-Tech systems
  • Mega Jet - see Sega Mega Jet
  • LaserActive - A LaserDisc player from Pioneer that can plug in modules. One of these modules allow users to play Mega Drive, Mega-CD and Mega LD games. It can display Mega Drive graphics over streamed video from compatible LaserDiscs.
    • Only a handful of games were released on the Mega LD format.
    • 3D Glasses have been produced for compatible discs.
    • Other modules could play the PC Engine games and add karaoke functionality.
  • Teradrive - An 286 PC manufactured by IBM with an integrated Mega Drive. Released in Japan only.
    • Three models were available, ranging from 148,000 to 248,000. Only the top-of-the-range model was supplied with a hard disk.
    • A special monitor (sold separately) was available, which could display both 15kHz RGB video signals from the Mega Drive hardware and the 31kHz VGA output of the PC hardware, both from the VGA connector.
    • Also had composite NTSC video and stereo RCA jacks for connection to a TV.
    • Mega Drive games can be played at the same time as the PC section is being used.
    • It was possible for the Mega Drive and PC hardware to interact with each other, as shown with the Puzzle Construction program. It was possible for Mega Drive software to be run from the PC's RAM. (Reference (
  • Mega PC - A system made by Amstrad with Mega Drive and IBM-compatible PC functionality in one - similar to the Teradrive, but by no means a related project. Produced under license from Sega.
    • PC section used an Intel i386SX running at 25 MHz. It had 1 MB of RAM and a 40-MB IBM-compatible hard disk drive.
    • Released in Europe around 1992-3
    • Coloured cream instead of the dark grey Teradrive, with a sliding cover on the front to change between Mega Drive and PC "mode".
    • Output from the Mega Drive section was only available through the VGA connector, to the supplied dual-scan (15kHz/31kHz) monitor.
    • Though the PC section is always running when the system is switched on, Mega Drive software cannot be used at the same time as PC software as there is only one video output.
    • Could also be used with a Mega CD with the use of a special connector only available from Amstrad.
    • Most of the Mega Drive hardware is contained on an 8-bit ISA card, with AdLib-compatible sound on the same board.
    • The Mega Plus was an updated version of the Mega CD. It used an i486 at 33 MHz and 4 MB of RAM.
  • Some MSX machines released only in Arab countries by a company named Universal, which along with MSX software could also (allegedly) play Mega Drive games.
    • The A330 MSX had a cartridge port on the top of the machine. It has 'Painting', 'Calendar', 'Arabic Writing', and 'English Writing' as its programs.
    • The AX990 had 50 programs. They are likely to be an unofficial multicart or other MSX programs.


More screenshots can be found in the gallery of Sega Genesis screenshots.

Technical specifications


  • Main processor: 16-bit Motorola M68000 (or equivalent)
    • runs at 7.61 MHz in PAL consoles, 7.67 MHz in NTSC consoles
  • Sound processor: 8-bit Zilog Z80a (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
    • runs when console is first switched on
    • contains "copyright check" code for locking out unlicensed games
    • displays message "Produced by or under license from Sega Enterprises Ltd." when a licensed game is detected
    • Boot ROM is not present on earlier versions of the Mega Drive 1
    • The name Sega gave this boot ROM was the TMSS (TradeMark Security System)
  • Main RAM: 64 KB
    • part of M68000 address space
  • Video RAM: 64 KB
    • cannot be accessed directly by CPU, must be read and written via VDP (Video Display Processor - see below)
  • Sound RAM: 8 KB
    • part of Z80 address space
    • used as main RAM in Master System compatibility mode
  • Cartridge memory area: up to 4 MB (32 Megabits)
    • part of M68000 address space
    • Game cartridges larger than 4 MB 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.

  • Planes: 4 (2 scrolling playfields, 1 sprite plane, 1 'window' plane)
  • Sprites: up to 80 on-screen, depending on display mode
  • Palette: 512 colours
  • Onscreen colours: 64 9-bit words of colour RAM, allowing 61 on-screen colours (up to 1536 using raster effects and Shadow/Hilight mode)
  • Pixel resolution: depends on display mode
    • up to 320240 (4030 cells) for PAL
    • up to 320224 (4028 cells) for NTSC
    • interlaced modes can provide double the vertical resolution (i.e. 320448 for NTSC). Used in Sonic 2 for two-player split screen


  • Main sound chip: Yamaha YM2612 six-channel FM
  • Additional sound chip: Texas Instruments SN76489 four-channel PSG (Programmable Sound Generator)
    • three sound generators, four octaves each, one white noise generator

Inputs and outputs

  • RF output: connects to TV aerial input
    • exists on European and Asian Mega Drive 1 only
    • other models must use external RF modulator which plugs into A/V output
  • A/V output: DIN connector with composite video, RGB, and audio outputs
    • Mega Drive 1 has 8-pin socket (same as Master System), supports mono audio only
    • Mega Drive 2, Multimega, and other models have 9-pin mini DIN socket with both mono and stereo audio, and s-video
  • Power input: 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 (Mega Drive 1 only)
    • Also suitable for passive speakers
  • "EXT" port: 9-pin D socket for Meganet modem connection
    • exists on all Japanese and Asian Mega Drive 1 units, and on early European Mega Drive 1 units
  • Control pad inputs: 2 9-pin D connectors on front of console
  • Expansion port: Edge connector on bottom right hand side of console for Sega Mega-CD connection


  • Signal/Noise Ratio: 14 dB

See also

External links

eo:Mega Drive es:Sega Mega Drive fr:Megadrive nl:Sega Mega Drive ja:メガドライブ pt:Mega Drive fi:Sega Mega Drive sv:Mega Drive


Academic Kids Menu

  • Art and Cultures
    • Art (
    • Architecture (
    • Cultures (
    • Music (
    • Musical Instruments (
  • Biographies (
  • Clipart (
  • Geography (
    • Countries of the World (
    • Maps (
    • Flags (
    • Continents (
  • History (
    • Ancient Civilizations (
    • Industrial Revolution (
    • Middle Ages (
    • Prehistory (
    • Renaissance (
    • Timelines (
    • United States (
    • Wars (
    • World History (
  • Human Body (
  • Mathematics (
  • Reference (
  • Science (
    • Animals (
    • Aviation (
    • Dinosaurs (
    • Earth (
    • Inventions (
    • Physical Science (
    • Plants (
    • Scientists (
  • Social Studies (
    • Anthropology (
    • Economics (
    • Government (
    • Religion (
    • Holidays (
  • Space and Astronomy
    • Solar System (
    • Planets (
  • Sports (
  • Timelines (
  • Weather (
  • US States (


  • Home Page (
  • Contact Us (

  • Clip Art (
Personal tools