Adding MAME games may be not as easy as adding traditional console games. If you are starting with PRG 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 PRG 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:
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 dkong.zip file plus the small differences for the japanese version called dkongj.zip.
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 PRG you may need to install several MAME emulators so you can use different dumps, but in PRG 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
These are the different version of MAME supported in PRG
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: