Adding MAME games may be not as easy as adding traditional console games. If you are starting with RetroX we don’t recommend you to start with MAME games, it’s easier to add any NES/SNES/Genesis/MegaDrive game to get an idea of how RetroX works and then try more complex systems like MAME and computer games.

Having said that, these are the two main reasons why MAME game are different from console games:

  1. One MAME game may require more than one file.  A MAME game is distributed in one or several files
  2. There are many versions of MAME. A file that works for one version may not work for a different version

In MAME jargon, a “dump” is a ZIP or 7Z file containing the data from the ROM chips of one Arcade Machine. At those times it was common that one game had different versions, like one version for Japan, another one for the Americas, Europe, etc.  Also there were bootleg versions that had some changes over the original game. All those versions are preserved by the MAME community but instead of having complete copies of each version of each game, they have a main dump with the original game plus smaller dumps with the differences for each version. For example if you want to run the japanese version of Donkey Kong you will need the main file plus the small differences for the japanese version called

In MAME you will also find “ROM Sets” that are complete collections of MAME games with all the versions for each game. They can be quite big, the smaller one is 2GB and as the MAME project progresses and more games are supported, the sets become bigger.

A ROM set is targeted for one MAME version. Dumps from one set may or may not work in other versions of MAME.

Without RetroX you may need to install several MAME emulators so you can use different dumps, but in RetroX is a matter of selecting which version you want to use. Also, you can select the version later, just before launching the game in the game details screen. That will allow you to quickly test which version of MAME is better to run your particular dump.  Also you can look for ROM Sets for a specific MAME version so you will know exactly which version to use.

A common question is why there are different versions of MAME supported. Well, as most software, MAME emulation improves with time, so more arcade machine types are added in each MAME release. But, as emulation improves and get more perfect, the processor requirements to run the emulators increase as well (learn more).

These are the different version of MAME supported in RetroX

  • 2001 – 0.37b : This will work on any device but will not support modern games, or their support will be limited. The ROM Set for this version is the smallest one (2GB) and it is the easiest starting point for enjoying MAME games
  • 2003 – 0.78 : This will work fine on any modern device. It improves support for some games, fixing sound problems in some 2001 games. ROM Set size is around 16GB
  • 2010 – 0.139 : This one may require a powerful device. It’s the only one version that support saving states. ROM Set size is around 24GB
  • 2014 – 0.159 : This includes support for modern games including some very popular modern shooters. Those games require a fast device like the NVIDIA Shield TV.  ROM Set size is around… should be quite bit. We haven’t seen it.

If you don’t know which version is your dump for, most probably they are for the latest version (2014+).

Some common problems that you may see when adding MAME games are:

  • Games are not scanned properly by RetroX.  Make sure that you have a folder with several small zip or 7z files, those are valid dumps to be scanned. Don’t put a big ZIP file with all the dumps inside of it, like a ROM Set in one big zip/rar/7z file.
  • RetroX says that it needs an additional file. This is because the file that you added in RetroX is not enough to run the game, remember that one game may require more than one file to run. RetroX will tell you which is the file that you are missing. A typical case is the file which is the Neo Geo BIOS dump.  Just get that file and put it in the same folder as your game, then use the “re-scan” option to let RetroX know that you added the missing files.
  • The game doesn’t start and RetroX is showing the in-game options.  This happens when MAME cannot recognize the dump, because the dump is for a different MAME version.  Try with a different version with the option that is available in the game details screen.