Multi Emulator Super System

"MESS" redirects here. For other uses, see mess (disambiguation).

MESS

Developer(s)	MESS Team
Stable release	0.144 / November 15, 2011; 4 days ago (2011-11-15)
Operating system	Cross-platform
Type	Emulator
License	Custom
Website	www.mess.org mess.redump.net

Multi Emulator Super System (MESS) is an emulator for many game consoles and computer systems, based on the MAME core.

The primary purpose of MESS is to preserve decades of computer and console history. As technology continues to progress, MESS prevents these vintage systems from being lost and forgotten.

MESS emulates portable and console gaming systems, computer platforms, and calculators. The project strives for accuracy and portability and therefore is not always the fastest emulator for any one particular system. However, its accuracy makes it useful for homebrew game development, for example on the Atari 7800.^[1]

MESS supports 679 unique systems with 1663 total system variations and is constantly growing. However, not all of the systems in MESS are functional; some are marked as non-working or are in development. MESS was first released in 1998 and has been under constant development since.

License

MESS is distributed under the MAME Licence, which allows for the redistribution of binary files and source code, either modified or unmodified, but disallows selling MESS or using it commercially.^[2] The license is similar to other copyleft licenses in requiring that rights and obligations provided in the license must be remain intact when MESS or derivative works are distributed.

In addition to the MESS Licence, The MESS Team requires that: "MESS must be distributed only in the original archives. You are not allowed to distribute a modified version, nor to remove and/or add files to the archive. Adding one text file to advertise your web site is tolerated only if your site contributes original material to the emulation scene."^[3] The MAME license requires source code be included with versions of MESS that are modified from the original source, while the MESS legal page states that when distributing binary files "you should also distribute the source code. If you can't do that, you must provide a pointer to a place where the source can be obtained."

While MESS is available at no cost in both binary and source code forms, the restrictions on commercial exploitation cause it to fall outside of the Free Software Foundation's definition of "free software". Similarly MESS is not considered to be open source software if appraised according to the criteria of the Open Source Definition.

Challenges

Main article: ROM image

Generally the emulation only includes raw hardware logic, such as for the CPU and RAM, and specialized DSPs such as tone generators or video sprites. The MESS emulator does not include any programming code stored in ROM chips from the emulated computer, since this may be copyrighted software.

Obtaining the ROM data by oneself directly from the hardware being emulated can be extremely difficult, technical, and expensive, since it may require desoldering of integrated circuit chips from the circuit board of the device they own. The desoldered IC is placed into an expensive chip reader device connected to the serial port of another computer, with pin sockets on the reader specifically designed to match the chip package shape in question, to perform a memory dump of the ROM to a data file.

Removal of a soldered chip is often far easier than reinstalling it, especially for extremely small surface mount technology chips, and the emulated device in question may be effectively destroyed beyond recovery after the ROM has been removed for reading.

However, if one has a working system, it is far easier to dump the ROM data to tape, disk, etc. and transfer the data file to one's target machine.

See also

• HazeMD, Side-project which emulates only the Sega Mega Drive using the MAME code.
• MAME

References

1. ^ Grand, Joe; Frank Thornton, Albert Yarusso (2004). Game Console Hacking: Xbox, Playstation, Nintendo, Atari, & Gamepark 32. Syngress. p. 506. ISBN 1931836210. 
2. ^ "MESS Licence". The MESS Development Team. http://mess.redump.net/license. Retrieved 25 March 2011. 
3. ^ "MESS Legal". The MESS Development Team. http://www.mess.org/legal.php. Retrieved 25 March 2011. 

External links

• Official MESS website
• Official MESS Wiki