Two fans have reportedly fixed the AtGames Genesis audio issues

A decade-old problem solved with a hex editor?

When we talk about Genesis clones, everyone always remember a very known issue: the audio. Companies like AtGames have been releasing Genesis clones for a decade and nearly every release has the been hampered by poor sound quality.

Earlier this year Brazilian tech company TecToy released their new Mega Drive to celebrate 30 year of partnership with SEGA. While this version is better than previous clone consoles, it shares the same Red Kid 2500 processor that has been used in AtGames systems, which means it has audio issues, as well.

But a recent discovery has been made by two fans Neto and Rafael Müller named that could completely fix the audio issues in the AtGames and TecToy Genesis systems.

The recent TecToy Genesis contained a file called md.bin on its packaged SD card. This file sends instructions to the processor to tell it how to execute the games. After a month of digging into the bin file and system, the duo made some interesting discoveries.

Most importantly, they discovered that the clock speed was wrong, which was reportedly the reason the Red Kid 2500 processor had bad audio. Adjusting the clock speed to the correct setting got the sound at about 85-90 percent accuracy of the original Genesis.

Upon hearing this news, fans began messaging TecToy requesting that the company implement this as an official update, and surprising enough, TecToy has announced that they’ll do just that.

Neto and Rafael didn’t stop their work with the TecToy Mega Drive, though. Because it and the AtGames’ Genesis clones and handhelds share the same processor, the two were able to implement this fix on one of their handhelds.

This is pretty impressive work that the duo were able to solve a decade-old problem by using a hex decimal editor and Assembly. Neto and Rafael deserve a lot of credit for fixing a problem that big companies did not have the courage to fix.

If you want to try this fix, take the following steps:

  1. Download the latest firmware for the new Mega Drive;
  2. Inside the file, you will have two files the MDI.BIN (New Mega Drive) and Neto_Boot_Loader.BIN (Portable Mega Drive);
  3. Place the Neto_Boot_Loader.BIN file in the GAME folder and through the MD Play menu load it through the SD option;
  4. From now, all the functions will be the same as the new TecToy Mega Drive with all the benefits of applied patches.

Here’s another video to see the difference between the original and the modified file:

Luiz Nai

I'm huge fan of Sega, I have been playing Sega games for over 20 years and games like Shenmue, Skies of Arcadia, Panzer Dragoon Saga and also all the Arcades race games are my favorites. Besides of playing Sega games I have a post degree in Game development and I enjoy playing guitar in my free time.

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  • Vomitcore

    Sega and their fans in 2017.

  • Mike Herron

    Much better, but still a little off. I’ll take it over the original anyday though!

    • Joao Silva

      Master of obvious!!! Without the Yamaha chip the sound will NEVER be the same!

      • Mike Herron

        Not necessarily. A good emulator can mimic the Yamaha chip flawlessly. This was just poor emulation choice by At Games and Tec Toy. My Kega Fusion emulator plays Sega games with perfect sound.

        • Joao Silva

          The new Mega Drive from Tectoy it´s not an emulator…. It´s a SOC Mega Drive, I will not explain here how a SOC works, but it´s not an emulator!!!

          • Sionyn Foulkes Jones

            Joao, both of them use a system on a chip. A system on a chip is exactly what it says a processor and io on a die a complete system on a chip.

            You still need emulation software to translate megadrive 6800 processor to what ever arch is used inside these clones.

            What the others have said still stands sound requires accurate emulation. Accurate emulation is costly when your using cheep embedded processors.

            You could implement a megadrive with both its video display processor cpu z80 and yamaha fm synth in a fpga or a ASIC. But that would costly compared to a off the shelf SoC and readily available emulation software.

      • Franpa

        Joao, the consoles emulate the original hardware don’t they? ie: there is an operating system and an emulator program running within that operating system that emulates the console?

        If that is the case, than the problem comes down to the emulator’s emulation accuracy and not physical hardware issues.

        • Joao Silva

          The new Mega Drive from Tectoy it´s not an emulator…. It´s a SOC Mega Drive, I will not explain here how a SOC works, but it´s not an emulator!

          • Big_Z zcbtkn

            What about the one from Atgames?

  • Robert_Tilton

    Doesn’t seem to work on the older atgames portables.

    • Hi Robert, you need to leave roms folders with this structure:!LhVVwLAZ!xed46vn9NcrLwDaHOvYf26ZJ2GPFnTiU2AdVV3yZKZY

      Then you replace the mdi.bin for the correct one provided on Neto’s website!! Let me know if you have any doubts!

      • Great Luiz,my friend,I have Atgames megarive portable (white edition) but I never works with SD cards… could you help me to fix it?

        • Of course! I have you on FB! Send me a message inbox!

          • Hi! I could finally fix it, thank you anyway! 🙂

          • Paul Rid

            Hi GAM3ER BAY, would it be possible to share the steps you took to fix the SD card reader, I just got one of these yesterday and i’ve tried about 5 different SD cards. Any help would be much appreciated. Thanks.

          • Paul Rid

            No matter, I have managed to get my SD Card to read correctly. For anybody that may be interested the solution was to use the official SD card formatting tool that can be dowloaded for free here: Also, for the black screen problem you were experiencing, I believe it is a problem of folder layout. I ran into the same problem. To overcome this, if you copy the TECTOY directory (can be found in the ROMs archive that Luiz referenced earlier) into the root of the SD CARD (say x:TECTOY) and copy the boot loader to x:GAMESneto_boot_loader.bin you should be laughing. Cheers for this article and the work put in by everyone. Awesome.

  • Sionyn Foulkes Jones

    Still sounds awful the audio is so distorted. Better but shows how at games couldn’t careless and instead just in this for a quick money grab

  • Kitsune Shan

    Im using it with the AtGames version and it does works pretty well. I just dont know what I should do to have the games show the cover rather than a SD card icon. How do I know which names do I have to give the roms? How do I add or change the images? I know how to do it with the default system but not with this new one.
    I am also getting a weird message saying that the rom its meant to use on a NTSC system, then when opening NTSC roms it says I need to use them on PAL system. Not sure if it have something to do with the extension of some files being “.gen” rather than “.bin” but on the default system all of them worked perfectly fine.

    One more thing, could be possible to enable save games on games like Sonic 3? My atgames console does save games but not those that are on the SD card.

    • Storminator16
      • Kitsune Shan


        • I did a package with many roms and also the covers:

          • When i execute neto_boot_loader.bin I entry in megadrive tectoy menu, but i push start button in that menu and screen goes to black…and nothing more :S
            My console is atgames megadrive ultimate portable game player (mortal kombat edition, display 3.2″)

  • Amber Werhane

    Does this work with the classic game console 2016? The non-portable one.

  • Intiakel

    I’ll be honest, doesn’t really sound any better, just a bit quieter. Nothing like the improvement on the 8-bit guy’s SOC genesis.

  • StingInTheTail2000

    I’m gonna try thus, I have newer white/black/blue/gray portable. Hope it works. Unfortunately I have to find an SD card adapter first, because my laptop inexcusably was not manufactured with one, even though its from the later 2000s.

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