Mega Drive

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Sega Mega Drive Mk1

The Sega Mega Drive, known as the Genesis in North America, is a 16-bit home video game console developed and sold by Sega. The Mega Drive was Sega's third console and the successor to the Master System. Sega released it as the Mega Drive in Japan in 1988, followed by North America as the Genesis in 1989. In 1990, it was distributed as the Mega Drive by Virgin Mastertronic in Europe, Ozisoft in Australasia, and Tec Toy in Brazil.


Model Image CPU Co-processor RAM ROM Graphics Display Sound Connectivity
Mega Drive Mega Drive 16-bit Motorola 68000 running at 7.61 MHz Zilog Z80 64 KB 1 MB VDP (Video Display Processor) dedicated video display processor for playfield and sprite control, 3 Planes, 2 scrolling playfields, 1 sprite plane. 64 KB VRAM. Progressive: 320x224, 256x224 (NTSC) or 320x240, 256x240 (PAL) pixels, 64 colors on-screen from a 512 colour palette.

Interlaced: 320x448, 256x448 (NTSC) or 320x480, 256x480 (PAL)

Texas Instruments SN76489 chip, Yamaha YM2612 FM chip. 6 stereo sound channels. 8 KB sound ROM. DE-9 controller port
Mega Drive 2 Mega Drive 2

Buying Guide

A good guide for buying has been created on the forum

Straight to the point, Mega Drive Mk1 with 'High Definition Graphics' printed on the top cover is the revision to be on the lookout for when buying.



As with most consoles of this age, capacitors should be one of the first things that are replaced. That being the case, don't just use the cheapest capacitors on eBay, there is a reason a lot of these consoles are still working today, and that is because decent capacitors were used in the first place. Replacing them with cheap capacitors may negate the process. When sourcing capacitors, look for well-known brands like Rubycon, Nichicon, Nippon Chemi-Con, Sanyo, and Panasonic

Guides to capacitor replacement and lists of values for each model can be found at


Stereo Audio RGB Cable
Stereo Audio RGB Cable

50/60 Hz Switch

A switch added to the unit which toggles between a 50 Hz and 60 Hz output. This will not only allow playing imported games in full-screen mode instead of the squashed letterbox mode but will also play them at full speed - almost 20% faster than normal PAL speed.

Language Switch

In addition to adding a 50/60 Hz switch, this additional switch toggles the language setting of the game being played. This can have some quite interesting effects on the games. This is because many of the game cartridges actual have two versions of the game - a Japanese version and an English version. While the basic gameplay will remain the same, there may be some subtle differences. Characters may have different names, music may be different and even the game may have a different name.

Widen Cartridge Slot

The modifications described above will allow you to play all games with a slot converter. Japanese Imports cannot (usually) be played without a converter, as the cartridges are bigger than the PAL Sega Megadrive. Although, the cartridge slot can be widened to allow foreign cartridges to fit.

Stereo Audio RGB Cable

The Mega Drive Mk1 only outputs stereo through its headphone port. Playing stereo audio through the TV can be achieved simply by using a modified RGB cable. A guide for creating the cable can be found at or, among other sites, can be purchased from

Storage Solutions

Mega Everdrive

Mega EverDrive X7

As with most cartridge-based consoles, there is a modern flash-based storage solution. Although other brands exist, EverDrive proves to be one of the most reliable.

This flash cart comes in 3 versions; X3, X5, and X7. More information can be found at

The carts can be purchased at (UK) and (US)