[MAME 2014 Reference Set]

Contents:
    Complete MAME 0.159 ROM set with CHDs
    Complete MAME 0.159 audio samples set*
    MAME 0.159 DAT file and ClrMamePro software for validation
    Original MAME 0.159 source and executable packages (mame0159b and mame0159s)

This is a complete set of ROMs, CHDs, and audio samples for MAME 0.159. This reference set includes the XML datfile generated by the included MAME 0.159 binary. MAME 0.159 generates a datfile with improper 'merge' tags for 'funkyfiga' and 'lucky8a'. This DAT file leaves those merge tags in place, but the zipped ROMs themselves are correct. 

This collection also includes the version of ClrMamePro which was used to verify the ROMs, CHDs, and samples. The TorrentZip executable included with the set was used to process each ROM and sample zip prior to distribution.

* Several audio samples, described in a text file within the collection, have never been publicly circulated and are not included.

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[ROM Set Format: Non-Merged]

Using a Non-Merged set means that every .zip in this collection is a complete ROM that can be used stand-alone.

The question of merged, split, and non-merged ROM sets has to do with "parent" and "clone" games. The parent is the primary or original version of a game. With all varieties (merged, split, non-merged) of MAME ROM sets, the parent ROM has all the files needed to play them within the .zip file.

Clones are a variant of the Parent. Here is where the differences between set types comes into play. Clones often feature a different language or updates to the game software. Some clones are "bootleg" versions of a ROM -- for example bootlegs that remove encryption that which makes the "parent" ROM unplayable. For these and other reasons, clone ROMs are sometimes the preferred version of a game.

"Merged" and "Split" sets save drive space by consolidating the parts of the clone ROM that are identical to its parent into the parent's zip file. The only benefit to this approach is saved space. On the other hand, not all emulators support Merged and Split sets. Those set formats are also make it more challenging to manually copy individual ROMs for use with an emulator rather than using the whole set.

Non-Merged -- such as this set -- arranges all games, parents and clones, in their own stand-alone .zip files with all of the files needed to run the game. This takes somewhat more storage space but removes clone dependencies on parents, meaning you can take any of these .zip files (including clones), put them in the appropriate emulator ROM directory on their own, and they should work.

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[About MAME and Standardized ROM Sets]

MAME's purpose is to keep arcade and video game systems from being lost and forgotten by documenting these systems and how they function. As arcade emulation became more and more practical on home computers, MAME emerged as the dominant platform for open source development efforts and the distribution of ROM sets.

In its early years, new monthly updates to MAME often brought significant advances in compatibility and features. MAME users generally had to choose to either keep their ROM, CHDs, and audio samples up to date with the latest version of MAME, or to put together a system that was frozen to whatever version of the ROM set and emulator software was current at the time.

Today, the MAME release cycle is still to produce a new stable version each month. Each update to the emulator still means updates to the ROMs and other media associated with each game and system that MAME supports. In this more mature era for arcade emulation, many changes to the emulator are focused on more accurate emulation, which requires more processing power on the host system but only sometimes results in improved playability.

Recent years have also made it easier and easier to install some flavor of MAME and a frontend onto mini/embedded systems and portable devices. These use cases, along with the more traditional scenario of installing MAME on a retired laptop or desktop, also benefit from access to standardized older ROM sets and MAME emulation because they have lower performance.

Many people use arcade emulators via frontends that may provide access to console emulators or have usability features like automated in-game art downloading. Here too it can be advantageous to have access to stable and standardized ROM sets that are certified to work with the frontend.