Master System:FM Audio Information

ApolloBoy



= History =

The Sega Mark III was a console launched in Japan in 1985 that was the initial version of the Sega Master System hardware. It was essentially a heavily upgraded SG-1000, featuring a new graphics chip and increased RAM. However, the Mark III still used a derivative of the Texas Instruments SN76489 PSG chip used in that earlier console, which was beginning to show its age by 1985. To rectify this, Sega released an audio expansion in 1987 known as the FM Sound Unit, which connected to the Mark III's expansion port and mixed the console's audio signal via a 5-pin DIN cable. This expansion was based around a Yamaha YM2413 FM synthesizer chip, which was also utilized in several arcade games, consumer-level music keyboards and an MSX audio expansion. Though this chip massively expanded the Mark III's audio capabilities, it was not as sophisticated as the YM2612 later used in the Sega Genesis/Mega Drive and was not fully programmable in terms of instrument patches.

= Examples =

= Supported Games =

A large number of games released from 1987 to 1989 feature FM audio capability, even on Western releases despite the FM Sound Unit never being released or featured in any hardware outside of Japan. This is because Sega used the same ROM file for these games across regions, so the FM audio code remained intact.

Officially Supported
These are games which were released in Japan and explicitly advertised support for the FM Sound Unit. The international versions of these games also still retain FM support with a couple of exceptions.

Unofficial Support
These are games which will support a detected FM Sound Unit, but this was not explicitly advertised as these games were released outside Japan where the FM audio hardware was unreleased.

= FM Audio on Real Hardware =

There are several methods that allow you to play your SMS games on original hardware with FM sound. Some require console modifications and others do not:

SMSFM Mod
Tim Worthington sells an FM kit that can be installed in an SMS console. Installation in an original SMS is fairly simple, as it plugs directly into the rear expansion port, requiring only three wires to be soldered. The kit can also be installed into a Master System II, either via wiring the kit directly into the motherboard or by using a special adapter from Consoles Unleashed. There have also been reports of people installing this kit into a Power Base Converter, or even a Genesis itself, but no instructions for that are available.

Power Base Mini FM
The Power Base Mini FM is a cartridge converter designed by dB-Electronics for the Genesis/Mega Drive which provides backwards compatibility with SMS cartridges complete with additional FM audio. This will also work with SMS [romcarts.html flash carts] such as the Master Everdrive.

Japanese SMS/MK-2000
Another option is the Japanese Sega Master System console (model number MK-2000), which has a YM2413, 3D glasses adapter and rapid fire module all built into the console itself. These were all separate add-ons for the Mark III. However, the Japanese SMS is not compatible with non-Japanese cartridges and will require a cartridge adapter for these games.

**SMS2SG1000** **Pro's:** Uses the top cartridge slot, so no modification needs to be made to the console; Just plug and play. **Con's:** The game cartridges look a little silly sticking that high up above the console. If you're using a Master Everdrive, it's recommended you use OSv7 with this adapter.zip). As an FYI, after flashing to OSv7,the SD card needs to be re-formatted to FAT32.

SMS Rear Adapter

Pro's: Sits behind the unit, so your console always looks "clean".

Con's: A small bit of plastic needs to be cut for it to fit properly & if you're using cartridges, it's a pain to go behind the unit each time to switch it out. Also, there's some compatibility issues with some games and ROM carts.

If you're using an original Master Everdrive, it's recommended you use OSv6 with this adapter.zip). As an FYI, after flashing to OSv6,the SD card needs to be re-formatted to FAT16.

Using a [romcarts.html ROM Cart] that supports FM Audio

There's a few ROM carts available for the Sega Genesis that use their FPGA chip inside to emulate the SMS' FM audio chip. There's one ROM cart for the SMS that has the FM chip built in, but it requires a modification to your console and it's confusing to use. Here's the choices:

Mega Everdrive Pro (includes Sega CD Support):  http://bit.ly/megaedpro Mega SD (also includes Sega CD Support):  https://bit.ly/terraonionmegasd Mega Everdrive x7:  https://stoneagegamer.com/flash/genesis/carts/mega-everdrive-x7/?afmc=retrorgb

The "Neo" ROM carts for both SMS and Genesis support FM audio:

Genesis Version = NEO Myth MD 3in1: http://www.ic2005.com/shop/product.php?productid=33&cat=3&page=1

SMS Version = NEO SEGA MKiii: http://www.ic2005.com/shop/product.php?productid=130&cat=3&page=1 Please note that the SMS version requires you to run the audio output of your SMS AV cable through it, for FM audio to be mixed in. If you're using RGB, you can try to order (or make) a custom SCART cable with an RCA audio output and input. Alternatively, you can use a Genesis RGB SCART cable that gets audio from the 3.5mm jack, then wire audio directly from the SMS' multi-out:  http://www.retrorgb.com/smsaudioout.html

While the NeoSD carts do work, I feel I need to warn you about a few things before proceeding:

Using the enhanced menu's is a must, as the stock menu's are terrible: Genesis cart enhanced menu: (1st post):  http://www.neoflash.com/forum/index.php/topic,5880.0.html **SMS cart enhanced menu:** http://www.neoflash.com/forum/index.php/topic,7199.0.html

The Neo carts are _not_ plug-and-play like the Everdrives, they actually require software to read and write ROMs. You can purchase an additional MicroSD card adapter, but it's expensive and you'll still need the software for initial setup (although after setup is complete, you can just read and write ROMs like a normal ROM cart):  http://www.ic2005.com/shop/product.php?productid=33&cat=3&page=1

Support is pretty bad. I had an issue with mine and it took over a month of exchanging emails with pictures and videos proving my issue before they agreed to a return.

Comparison of the above methods:

I have a few pretty outdated videos demonstrating the differences between the above choices. I also included an audio analysis section on the Mega Everdrive Pro review, so here's links to all of those: http://www.retrorgb.com/files/MK-2000-FMKit-NeoSMS-NeoMD.wav

https://youtu.be/ayKxnrYCpPI

https://youtu.be/KZMwYVIsuAE