ROM image
Encyclopedia
A ROM image, or ROM file, is a computer file which contains a copy of the data from a read-only memory
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...

 chip, often from a video game cartridge
ROM cartridge
A ROM cartridge, sometimes referred to as a cart, is a removable enclosure containing read-only memory devices designed to be connected to a computer or games console....

, a computer's firmware
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...

, or from an arcade game
Arcade game
An arcade game is a coin-operated entertainment machine, usually installed in public businesses such as restaurants, bars, and amusement arcades. Most arcade games are video games, pinball machines, electro-mechanical games, redemption games, and merchandisers...

's main board
Arcade system board
An arcade system board is a dedicated computer system created for the purpose of running video arcade games. Arcade system boards typically consist of a main system board with any number of supporting boards...

. The term is frequently used in the context of emulation
Video game console emulator
A video game console emulator is a program that allows a computer or modern console to emulate a different video game console's behavior. Emulators are most often used to play older video games on personal computers and modern video game consoles, but they are also used to play games translated...

, whereby older games or computer firmware are copied to ROM files on modern computers and can, using a piece of software known as an emulator
Video game console emulator
A video game console emulator is a program that allows a computer or modern console to emulate a different video game console's behavior. Emulators are most often used to play older video games on personal computers and modern video game consoles, but they are also used to play games translated...

, be run on the newer computer.

Creation

ROMs can be copied from the read-only memory chips found in cartridge-based games and many arcade machines using a dedicated device in a process known as dumping. For most common home video game systems, these devices are widely available. An example is the Doctor V64
Doctor V64
The Doctor V64 is a development and backup device made by Bung Enterprises Ltd that is used in conjunction with the Nintendo 64. The Doctor V64 also had the ability to play Video CDs, audio CDs and had an option for applying stereo 3D effects to the audio.- History :The Doctor V64 came out in 1996...

.

Dumping ROMs from arcade machines, which in fact are highly customized PCBs
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

, often requires individual setups for each machine along with a large amount of expertise.

Copy protection mechanisms

While ROM images are often used as a means of preserving the history of computer games, they are also often used to facilitate the unauthorized copying and redistribution of modern games. Seeing this as potentially reducing sales of their products, many game companies have incorporated features into newer games which are designed to prevent copying, while still allowing the original game to be played. For instance, the Nintendo GameCube
Nintendo GameCube
The , officially abbreviated to NGC in Japan and GCN in other regions, is a sixth generation video game console released by Nintendo on September 15, 2001 in Japan, November 18, 2001 in North America, May 3, 2002 in Europe, and May 17, 2002 in Australia...

 used non-standard 8 cm DVD-like optical media which for a long time prevented games from being copied to PCs. It was not until a security hole was found in Phantasy Star Online Episode I & II
Phantasy Star Online
Phantasy Star Online is an online multiplayer action RPG title, originally released for the Dreamcast in 2000, bundled with a demo of Sonic Adventure 2. Another edition, entitled Phantasy Star Online ver.2, was released for Dreamcast the following year...

 that GameCube games could be successfully copied to a PC, using the Gamecube itself to read the discs.

SNK
SNK Playmore
SNK Playmore Corporation is a Japanese video game hardware and software company. SNK is an acronym of , which was SNK's original name. The company's legal and trading name became SNK in 1986....

 also employed a protection on their Neo Geo
Neo Geo (console)
The is a cartridge-based arcade and home video game system released on July 1, 1991 by Japanese game company SNK. Being in the Fourth generation of Gaming, it was the first console in the former Neo Geo family, which only lived through the 1990s...

 games starting with The King of Fighters in 1999 which used an encryption algorithm on the graphics ROMs which prevented them from being played in an emulator. Many thought that this would mark the end of Neo Geo emulation. However, as early as 2000, hackers found a way to decrypt and dump the ROMs successfully, making them playable once again in any Neo Geo emulator.

Another company which used to protect their arcade games was Capcom
Capcom
is a Japanese developer and publisher of video games, known for creating multi-million-selling franchises such as Devil May Cry, Chaos Legion, Street Fighter, Mega Man and Resident Evil. Capcom developed and published Bionic Commando, Lost Planet and Dark Void too, but they are less known. Its...

 which is known for its CPS-2 arcade board. This contained a heavy copy protection algorithm which was not broken until 7 years after the system's release in 1993. The original crack by the CPS2Shock Team was not a true emulation of the protection because it used XOR tables to bypass the original encryption and allow the game to play in an emulator. Their stated intent was to wait until CPS-2 games were no longer profitable to release the decryption method (three years after the last game release). The full decryption algorithm was cracked in 2007 by Nicola Salmoria, Andreas Naive and Charles MacDonald of the MAME
MAME
MAME is an emulator application designed to recreate the hardware of arcade game systems in software on modern personal computers and other platforms. The intention is to preserve gaming history by preventing vintage games from being lost or forgotten...

 development team.

Another copy protection technique used in cartridge-games was to have the game attempt to write to ROM. On an authentic cartridge this would fail or cause an exception, however, emulators would often allow the write to succeed. Pirate cartridges also often used writable chips instead of ROM. By reading the value back to see whether the write succeeded, the game could tell whether it was running from an authentic cartridge. Alternatively, the game may simply attempt to overwrite critical program instructions, which if successful renders it unplayable.

Some games, such as Game Boy games, also had other hardware such as memory bank controllers connected to the cartridge bus. The game would send data to this hardware by attempting to write it to specific areas of ROM; thus, if the ROM were writable, this process would corrupt data.

Capcom's latest arcade board is the CPS-3
CPS-3
The or CPS-3 is an arcade system board that was first used by Capcom in 1996 with the arcade game Red Earth. It was the second successor to the CP System arcade hardware, following the CP System II...

. This was resistant to emulation attempts until June 2007, when the encryption method was reverse-engineered
Reverse engineering
Reverse engineering is the process of discovering the technological principles of a device, object, or system through analysis of its structure, function, and operation...

 by Andreas Naive. It is currently implemented by MAME
MAME
MAME is an emulator application designed to recreate the hardware of arcade game systems in software on modern personal computers and other platforms. The intention is to preserve gaming history by preventing vintage games from being lost or forgotten...

 and a variant of the CPS-2 emulator Nebula.

Software testing

ROM images are used when developing for embedded computers
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...

. Software which is being developed for embedded computers is often written to ROM files for testing on a standard computer before it is written to a ROM chip for use in the embedded system.

Digital preservation

The lifespan of digital media is rarely great. While black-and-white photographs may survive for a century or more, many digital media can become unreadable after only 10 years. This is beginning to become a problem as early computer systems may be presently fifty or sixty years old while early home video consoles may be almost thirty years old. Due to this aging, there is a significant worry that many early computer and video games may not survive without being transferred to new media. So, those with an interest in preservation are actively seeking older arcade and video games and attempting to dump them to ROM images. When stored on standardized media such as CD-ROMs and DVD-ROMs, they can be copied to future media with significantly reduced effort.

The trend towards mass digital distribution of ROMs images, while potentially damaging to copyright holders, may also have a positive effect on preservation. While over time many original copies of older games may deteriorate, be broken or thrown away, a copy in ROM or Image form may be distributed throughout the world, allowing games which would otherwise have been lost a greater chance of survival.

Hacks and fan translations

Once games have been made available in ROM format, it is possible for users to make modifications. This may take the form of altering graphics, changing game levels, tweaking difficulty factor, or even translation into a language for which a game was not originally made available. Hack
ROM hacking
ROM hacking is the process of modifying a video game ROM image to alter the game's graphics, dialogue, levels, gameplay, or other elements. This is usually done by technically inclined video game fans to breathe new life into a cherished old game, as a creative outlet, or to make essentially new...

s can often take humorous forms, as is the case with a hack of the NES
Nintendo Entertainment System
The Nintendo Entertainment System is an 8-bit video game console that was released by Nintendo in North America during 1985, in Europe during 1986 and Australia in 1987...

 version of Mario Bros.
Mario Bros.
is an arcade game published and developed by Nintendo in 1983. It was developed by Shigeru Miyamoto. It has been commonly featured as a minigame in the Super Mario Advance series and other games...

, entitled Afro Mario Brothers, which features the famous brothers wearing Afro haircut
Afro
Afro, sometimes shortened to fro and also known as a "natural", is a hairstyle worn naturally by people with lengthy kinky hair texture or specifically styled in such a fashion by individuals with naturally curly or straight hair...

s. The Metroid Redesign mod is a hack of Super Metroid
Super Metroid
, also known as Metroid 3, is an action-adventure video game and the third game in the Metroid series. It was designed by Nintendo Research & Development 1, programmed by Intelligent Systems, and published by Nintendo for the Super Nintendo Entertainment System video game console...

that revamps the game and adds new objectives.

A large scene has developed to translate games into other languages. Many games receive a release in one part of the world, but not in another. For example, many computer role-playing games released in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 go unreleased in the West and East outside of Japan. A group of fan translator
Fan translation
A fan translation, in video gaming, refers to an unofficial translation of a computer game or video game.The fan translation practice grew with the rise of video game console emulation in the late 1990s. A community of people developed that were interested in replaying and modifying the games they...

s will often translate the game themselves to meet obvious demand for titles. For example, the 1995 game Tales of Phantasia
Tales of Phantasia
is a Super Nintendo game in the RPG genre published by Namco and released in Japan in 1995, selling 212,000 copies. It is the first mothership title in the Tales RPG series and was later remade/re-released on the PlayStation, Game Boy Advance and PlayStation Portable...

was only officially released in Japan; DeJap Translations translated the game's on-screen text into English in 2001. Further to this, a project called Vocals of Phantasia was begun to translate the actual speech from the game. An official English version was not released until March 2006, some five years after the text translation was released. Another example was that of Mother 3, a Japan-only sequel to the cult-favorite Earthbound
EarthBound (series)
EarthBound, known in Japan as Mother, is a role-playing game series created by Shigesato Itoi for Nintendo. The series started in 1989 with the Japan-only release of Mother for the Famicom, and was then followed up by a sequel, released in North America as EarthBound for the Super NES in 1995, and...

. In spite of massive fan response and several petitions for an English translation, the only response from Nintendo was that Mother 3 would be translated and released in Europe, which it never was. Instead, the fan website Starmen.net undertook a massive translation project and released the translated version of Mother 3 in October, 2008. The translation was praised by fans and even employees from Nintendo, Square Enix, and other industry professionals.

The Japanese N64
Nintendo 64
The , often referred to as N64, was Nintendo′s third home video game console for the international market. Named for its 64-bit CPU, it was released in June 1996 in Japan, September 1996 in North America, March 1997 in Europe and Australia, September 1997 in France and December 1997 in Brazil...

 game Dōbutsu no Mori (Animal Forest) has also been translated into English. The game was originally only released on N64 in Japan, but it was ported to GameCube and renamed Animal Crossing
Animal Crossing
The Animal Crossing games have garnered positive response. The first three games are among the best-selling for their respective consoles. Animal Crossing has sold 2.321 million copies; Wild World 10.79 million; and City Folk 3.38 million...

.

Hacks may range from simple tweaks such as graphic fixes and cheats, to full-blown redesigns of the game, in effect creating an entirely new game using the original as a base.

One of the oldest games that has an active ROM hacking scene to this day is Super Mario Bros.

Copyright

In some countries, it is legal for an individual to personally make backup copies of a game they own. Individuals may make backup copies for various reasons, perhaps as insurance against losing the game or as redundancy in the event that the original game's medium becomes unreadable. See the section on ROMs and Preservation.

However, in the U.S. it has been illegal since 1983 for a user to create their own backups of video game ROMs onto other cartridges. This was decided in the court case of Atari v. JS&A. JS&A manufactured a "game backup" device that allowed users to dump their Atari ROMs onto a blank cartridge. JS&A argued that the archival rule allowed for this. The court disagreed, noting that ROM media was not subject to the same volatility as magnetic media (for which the law was created). Thus, not being so relatively vulnerable, ROMs were not applicable under section 17 USC 117(a)(2).

Chuck Cochems has put forth the argument that copying a legitimate item of software specifically for personal use with an emulator is legally justifiable under principles established by the Sony v. Universal ruling, particularly with regard to personal use being favorable towards justification under the fair use doctrine
Fair use
Fair use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work. In United States copyright law, fair use is a doctrine that permits limited use of copyrighted material without acquiring permission from the rights holders...

.

Some games companies, such as Nintendo
Nintendo
is a multinational corporation located in Kyoto, Japan. Founded on September 23, 1889 by Fusajiro Yamauchi, it produced handmade hanafuda cards. By 1963, the company had tried several small niche businesses, such as a cab company and a love hotel....

, print warnings inside their game manuals that they do not allow users to make backup or archival copies. Whether or not these warnings in this specific form can be considered valid contract
Contract
A contract is an agreement entered into by two parties or more with the intention of creating a legal obligation, which may have elements in writing. Contracts can be made orally. The remedy for breach of contract can be "damages" or compensation of money. In equity, the remedy can be specific...

s is legally questionable. For an overview of relevant issues, see user agreement (EULA), shrink wrap contract
Shrink wrap contract
Shrink wrap contracts are license agreements or other terms and conditions of a contractual nature which can only be read and accepted by the consumer after opening the product. The term describes the shrinkwrap plastic wrapping used to coat software boxes, though these contracts are not limited...

, clickwrap
Clickwrap
A clickwrap agreement is a common type of agreement often used in connection with software licenses. Such forms of agreement are mostly found on the Internet, as part of the installation process of many software packages, or in other circumstances where agreement is sought using electronic media...

, Fair Use
Fair use
Fair use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work. In United States copyright law, fair use is a doctrine that permits limited use of copyrighted material without acquiring permission from the rights holders...

, Fair Dealing
Fair dealing
Fair dealing is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work, which is found in many of the common law jurisdictions of the Commonwealth of Nations....

 and DMCA.

ROM images may be directly licensed by the rights holder. For example, Atari
Atari
Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...

 once made a number of their original arcade games available in ROM format which is compatible with the MAME
MAME
MAME is an emulator application designed to recreate the hardware of arcade game systems in software on modern personal computers and other platforms. The intention is to preserve gaming history by preventing vintage games from being lost or forgotten...

 emulator through the online ROM retailer Star ROMs. Nintendo
Nintendo
is a multinational corporation located in Kyoto, Japan. Founded on September 23, 1889 by Fusajiro Yamauchi, it produced handmade hanafuda cards. By 1963, the company had tried several small niche businesses, such as a cab company and a love hotel....

 provides a service on their 7th generation console, the Wii
Wii
The Wii is a home video game console released by Nintendo on November 19, 2006. As a seventh-generation console, the Wii primarily competes with Microsoft's Xbox 360 and Sony's PlayStation 3. Nintendo states that its console targets a broader demographic than that of the two others...

, that allows players to purchase old games from various systems, such as the NES
Nintendo Entertainment System
The Nintendo Entertainment System is an 8-bit video game console that was released by Nintendo in North America during 1985, in Europe during 1986 and Australia in 1987...

, which will download a ROM image and emulator upon purchase (see Virtual Console
Virtual console
A virtual console – also known as a virtual terminal – is a conceptual combination of the keyboard and display for a computer user interface. It is a feature of some operating systems such as UnixWare, Linux, and BSD, in which the system console of the computer can be used to switch between...

). This is similar to the PlayStation Store
PlayStation Store
The PlayStation Store is an online virtual market available to users of Sony's PlayStation 3 and PlayStation Portable game consoles via the PlayStation Network. The Store offers a range of downloadable content both for purchase and available free of charge. Available content includes full games,...

 re-releases of games for the original PlayStation
PlayStation
The is a 32-bit fifth-generation video game console first released by Sony Computer Entertainment in Japan on December 3, .The PlayStation was the first of the PlayStation series of consoles and handheld game devices. The PlayStation 2 was the console's successor in 2000...

 for the PlayStation 3
PlayStation 3
The is the third home video game console produced by Sony Computer Entertainment and the successor to the PlayStation 2 as part of the PlayStation series. The PlayStation 3 competes with Microsoft's Xbox 360 and Nintendo's Wii as part of the seventh generation of video game consoles...

 and PlayStation Portable
PlayStation Portable
The is a handheld game console manufactured and marketed by Sony Corporation Development of the console was announced during E3 2003, and it was unveiled on , 2004, at a Sony press conference before E3 2004...

, and the Xbox Live Arcade
Xbox Live Arcade
Xbox Live Arcade is a type of video game download distribution available primarily in a section of the Xbox Live Marketplace, Microsoft's digital distribution network for the Xbox 360, that focuses on smaller downloadable games from both major publishers and independent game developers...

's re-release of many old video games such as the original Sonic the Hedgehog for the Xbox 360
Xbox 360
The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...

.

The vast majority of computer and video games from the history of such games are no longer manufactured. As such, the copyright holders of some games have offered free licenses to those games, often on the condition that they be used for non-commercial purposes only. For example, fourteen of the games emulated in MAME, including Gridlee
Gridlee
Gridlee is a 1983 arcade game produced by Videa. Although it was never actually released, the game is playable through the emulator MAME. It is notable for being one of the few games in MAME which may be downloaded with permission from the copyright holders...

and Robby Roto
Robby Roto
The Adventures of Robby Roto! is a 1981 arcade game produced by Bally/Midway. It is no longer available in most arcades....

, have been made available under such licenses and are distributed by the MAME project.

Similar image types

Image files derived from computer tape
Magnetic tape data storage
Magnetic tape data storage uses digital recording on to magnetic tape to store digital information. Modern magnetic tape is most commonly packaged in cartridges and cassettes. The device that performs actual writing or reading of data is a tape drive...

 are known as tape image
Tape image
In the field of computer emulation, tape image is an image of a program which was distributed on tapes. In the old days of computing, applications were distributed on cartridges, floppy disks or cassette tapes. Many computers such as the TI-99/4A, Commodore 64, ZX Spectrum, et al...

s, while those derived from floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

s and CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

s (and other disk formats) are known as disk image
Disk image
A disk image is a single file or storage device containing the complete contents and structure representing a data storage medium or device, such as a hard drive, tape drive, floppy disk, CD/DVD/BD, or USB flash drive, although an image of an optical disc may be referred to as an optical disc image...

s. Images copied from optical media are also called ISO images, after one of the standard file system
File system
A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...

s for optical media, ISO 9660
ISO 9660
ISO 9660, also referred to as CDFS by some hardware and software providers, is a file system standard published by the International Organization for Standardization for optical disc media....

.

Creating images from other media is often considerably easier and can often be performed with off-the-shelf hardware. For example, the creation of tape image
Tape image
In the field of computer emulation, tape image is an image of a program which was distributed on tapes. In the old days of computing, applications were distributed on cartridges, floppy disks or cassette tapes. Many computers such as the TI-99/4A, Commodore 64, ZX Spectrum, et al...

s from games stored on magnetic tapes (from, for example, the Sinclair ZX80 computer) generally involves simply playing the magnetic tape using a standard audio tape player connected to the line-in of a PC sound card
Sound card
A sound card is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware...

. This is then recorded to an audio file and transformed into a tape image file using another program. Likewise, many CD and DVD games may be copied using a standard PC CD/DVD drive.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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