MAME Reference Sets

The MAME Reference Sets are listed below:

Emulators starting with lr- are libretro cores, so they enjoy all the benefits of that: centralized controller configurations, many customization options, netplay, shader/overlay support, etc.

In general these modified older versions of MAME were created for smaller systems with underpowered processors such as the Raspberry Pi.

Guide
To create any of the Reference ROMs and CHDs sets listed above (or any previous version not listed above as well), you need the corresponding DAT File to be used with a ROM Manager:

The datfiles can't be downloaded currently.

The guide on how to create the Reference Sets is at "MAME ROMs Set Creation using a dir2dat (With ClrMamePro)".

Merging Explained
It's recommended reading MAME Split Merged and Non-Merged Sets.