Playing Today – The Sega Megadrive

Continuing our guides on the basics of playing retro hardware in more modern times, this article focuses on the iconic Sega Megadrive console.

The Sega Megadrive, known as the Genesis in the USA, was Sega’s follow up to the 8 bit Master System. The system was a commercial success in Europe and the USA, where it was the main competitor to the Super Nintendo system. There were two main revisions of the hardware, along with several rarer more esoteric versions such as the Wondermega and the Nomad, which we will cover later.


The Mark 1 Megadrive/Genesis console.

The Mark 1 Megadrive/Genesis console.

The revised Mark 2 console.

The revised Mark 2 console.


Like other 4th generation consoles, most Megadrive games are displayed in 240p (NTSC) or 288p (PAL). A handful of games also use 480i screen modes and some will switch between the two. As regular readers of our site will be aware, modern HDTVs almost invariably handle 240p/288p signals incorrectly. Using a CRT or an upscaler with the system is highly recommended.

AV Output

Both the Sega Megadrive mark 1 and mark 2 consoles output composite video and RGB (but not S-Video). The mark 1 Sega Megadrive uses an 8 pin female U DIN connector while the mark 2 uses a 9 pin mini din connector. RGB cables are readily available for both versions of the machine. Full wiring diagrams for both consoles are available here for users who want to make their own cables.

There are a few important things to note regarding both consoles and their respective AV output. Notice on the Mega Drive 1 for instance that only mono audio is available from the AV connector. Most Megadrive SCART cables you can buy commercially will include a 3.5mm audio jack allowing for stereo audio to be connected from the headphone socket at the front of the console.

Pin 7 on the Megadrive 1’s AV output offers a raw/pure composite sync signal, however this signal is actually incorrectly wired internally in the console. To make use of it, a specially wired cable is required (such as those available here) or an internal modification. Interestingly, while using a raw/pure composite sync signal usually offers no benefits for the majority of equipment, in the case of the Megadrive it is highly recommended to use raw/pure composite sync wherever possible. If you are using an XRGB3 upscaler you must use a raw sync cable otherwise you are likely to experience screen blanking/picture loss during bright scenes in games.

Using the AV output on the Megadrive mark 2 is simpler. There are no issues with the raw/pure sync output and the mini-din connector also provides stereo audio.

Recently there has been an exciting development by Arcade-TV that can potentially further improve the picture quality  of the Megadrive/Genesis, read on to the next section for more details.

The Jailbar issue

Mark 1 Megadrive/Genesis consoles are notorious for having a jailbar pattern on the blue parts of the RGB signal. The severity of this problem seems to vary from console to console. There are two things you can do to minimise the issue. First of all, use a clean/raw sync cable with your console, such as the Pack-a-punch cable. Secondly, you can try lifting pin 50 on the VDP chip inside the console. Be aware that if you do this second modification, your Megadrive/Genesis console will be limited to RGB output only, composite video will no longer work.

The ultimate RGB upgrade and jailbar fix is likely to be to be the new RGB Bypass modification from Arcade-TV. This board takes the RGB directly from the Megadrives VDP (video processor chip) and sends it through a new, more modern RGB encoder. The end result is reported to be completely jailbar free and give a stunning RGB image, better than any Megadrive/Genesis console in history. We’re hoping to do a review of this part in the near future.

Sound issues

The quality of the audio output on the Megadrive/Genesis varies widely. The quality is regarded as being best in the early Mark 1 models. RetroRGB has written an extensive article on how to find the best model. If you have a newer model and want to improve the sound quality, it is possible to install a modification called the Mega Amp, which you can find out about here.


The Mark 1 Megadrive and Mega CD expansion unit (both mark 1 and mark 2) need a power supply that outputs 9 or 10 volts DC and at least 850 milliamp (1.2 amps recommended for the Mega CD). It must have a negative tip and the plug outer diameter needs to be 5.5mm, while the inner diameter should be 2.1mm. Power supplies from Super Famicom consoles should be cross compatible, however you should never use a power supply from a European Super Nintendo console as this power supply outputs AC voltage rather than DC.

The Mark 2 Megadrive and the 32X expansion unit need a power supply that outputs 9 or 10 volts DC and at least 850 milliamps. It must have a positive tip and the plug outer diameter needs to be 4.75mm while the inner diameter should be 1.7mm.


If you are not using a CRT, it is highly recommended to use an external upscaler with your Megadrive/Genesis console. This will drastically improve picture quality and in many cases reduce input lag too. You are likely to get better results using a cable wired for pure/raw sync output, rather than composite video for sync.

For some reason, Megadrive/Genesis games which use interlace output mode (e.g Sonic 3 in 2 player mode) are not compatible with the XRGB Mini upscaler. There is no problem when using the XRGB3 or DVDO upscalers.

Regional lockouts and circumventions

The Megadrive/Genesis console includes some basic regional locking. Circumventing this regional lockout requires either an adapter cartridge or a hardware modification. Import adapter cartridges typically plug into the consoles cartridge slot and then accommodate the import game as well as a local game that acts as a bypass to the regional lockout chip. Import adapter cartridges work with most games, but some have more advanced regional lockout protection and are therefore incompatible.

The switchless region free hardware modification that we offer on the site is 100% compatible with all Megadrive and Genesis games. This modification also allows the console to be switched between 50hz and 60hz modes. Keep in mind that when you switch a PAL console into NTSC mode, or vice versa, due to slight differences in the timing crystals in the machine the video signal will be ever so slightly out of spec. This can cause issues on some HDTVs, but CRTs are generally unaffected.

Japanese Megadrive cartridges are physically wider than their European and American counterparts. If you want to play all region games on a PAL Megadrive or US Genesis, we can widen the cartridge slot for you to accommodate this. Alternatively, if you do not want any cosmetic changes to your console you can use an import adapter instead.

Add ons

Megadrive and Mega CD Mark 1.

Megadrive and Mega CD Mark 1.

The Megadrive/Genesis has an unusual array of add ons. The most common add-on is the MegaCD or SegaCD unit. This comes in two different models, the Mark 1 and the Mark 2. You can use a Mark 1 Megadrive with a Mark 2 Sega CD and vice versa, if you have the correct mounting brackets. When shopping for a MegaCD second hand we strongly recommend you check that it includes all the correct fittings. Runing a Sega CD without the correct fitting brackets can produce unexpected results such as game crashing and glitching.

Sega also released a 32 bit upgrade in the form of the Sega 32X. The 32X was not commercially successful and only a handful of games were released for it.

Finally, a converter to allow Master System games to be played on the Megadrive was also released. Unlike the 32X and the SegaCD, you must buy the appropriate Master System converter for the specific revision of the Megadrive/Genesis you own. Finding a Master System converter for the mark 2 Sega Megadrive console is difficult, however it should be noted that Master System games will play from most Megadrive/Genesis flash carts without the need for a converter. Using Master System software on the Megadrive/Genesis in conjunction with an XRGB3 upscaler can be troublesome as you will need to manually adjust the AFC level. This can cause incompatibilities with many TVs or secondary scalers. Using a clean sync RGB cable is highly recommended.

Each add-on (apart from the Master System converter) requires a separate power supply, meaning that a fully configured Sega Megadrive/Genesis system will require three separate power supplies in order to run. To mitigate this issue you can use a specially designed third party power supply such as the one we reviewed here.

Other hardware revisions

Sega either produced or officially licensed the Megadrive and MegaCD hardware in several other, much rarer versions too.

The X’eye or Wondermega RG-M1 and RG-M2An all in one Megadrive and MegaCD with high quality CD audio playback. Curiously, it does not offer RGB output without a hardware modification.

Genesis CDX or Multi-Mega – This unit was a combination of the Genesis and Sega CD into one unit. Unique to this model was its additional functionality as a portable compact disc player. It’s highly sought after now by collectors. It can be modded with a switch-less region free modification.

The Sega Nomad – A handheld version of the Megadrive, extremely rare and sought after. The unit was spoiled by a high price and poor battery life.

Genesis 3 – A budget version of the console licensed and produced by Majesco Entertainment.

Pioneer Laseractive – This curious multi-format system had a module that allowed Sega Megadrive/Genesis games to be run from cartridge, CD and for a number of system exclusive laseractive games to be run from laserdisc. The Laseractive is region free but does not support RGB output.


Flash cartridges exist for the system, allowing ROM images to be loaded. These flash cartridges also circumvent regional lockouts in most cases. The better Megadrive/Genesis flash cartridges have close to 100% compatibility, with only titles like Virtua Racing (which included a special 3D processor chip inside the cartridge) proving incompatible. Many Megadrive flash cartridges also allow Sega Master System games to be loaded too.

The most popular flash cartridge is the Everdrive.


Many emulators exist for the Megadrive/Genesis. Emulation of the system can be an excellent way to enjoy Megadrive games on an HDTV.

Some Megadrive emulators are highly accurate. Many of the better emulators have pixel shaders and other graphical effects that can be used to scale and enhance the graphical output beyond what is possible even with a RGB modified console and an upscaler.

If you decide to emulate the system, you may wish to use a Megadrive to PC controller adapter. The models available from Raphnet and RetroUSB are reported to work well with minimal or no input lag.

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