From Retro Arcade Guides

MESS (Multi Emulator Super System), was the sister project of MAME. MESS was a source-available project which documented the hardware for a wide variety of (mostly vintage) computers, video game consoles, and calculators through software emulation, as MAME does for arcade games. As a nice side effect to this documentation, was that MESS allowed software and games for these hardware platforms to be run on modern PCs.

MESS was mostly programmed in C with some core components in C++, and shared its core and CPU emulation with MAME. This allowed MESS to offer the same powerful interface and flexible options which MAME offered for arcade emulation.

MESS could emulate over 1,450 individual systems, the oldest system emulated was released in 1948.

On 27 May 2015, MAME version 0.162 was released with MESS integrated. MESS will not be released stand-alone anymore, now it is part of MAME.

Purpose of MESS

The primary purpose of MESS was to preserve decades of computer and console history. As technology continued to rush forward, MESS prevented these important “vintage” systems from being lost and forgotten. MESS was based on MAME and shared many of its components.

Systems Emulated by MESS

ProjectMESS (broken) contains a complete list of the systems emulated. As you will notice, being supported does not always mean that the status of the emulation is perfect.

Alternatively, you could simply see the status by yourself, launching the system emulation and taking a look to the red or yellow warning screen which appears before the emulation starts, if any.