ROM (game module)

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ROM ( R EAD O nly M emory , dt. Read-only memory or read-only memory ) is a common designation for memory dump of the memory chip ( EPROM ), which in gaming memory plug-in modules - also Cartridges called - have been installed; they contain the data information of the actual game. These images can be used on the PC by means of emulators or, with writable plug-in modules, they can usually be played back on the original console. Images of console games on CD or DVD are usually called ISO or image. Floppy disks are referred to as disk images .

Legal situation

Owning and using emulators is fundamentally legal. However, some emulators require the BIOS of the respective device in order to run the ROMs , which must not be delivered with the emulator. The legality of ROMs is determined by corresponding regulations through laws for the protection of copyrights. If ROMs are not obtained from the copyright holder, the type and circumstances under which the copy was created are of particular relevance for legality. In Germany, Section 53 (reproductions for private and other personal use) of the Copyright Act applies .

In addition to commercial ROMs, there is also the homebrew scene, which deals with mostly unauthorized programming of third-party systems. For example, there are programmers who develop unlicensed on consoles and handhelds and whose products are available on the Internet as freeware. From a legal point of view, this is not illegal (in Germany), but it is in a gray area. The end products are often distributed as ROM and can be played with appropriate hardware or emulators.

ROM hacking

ROM hacking is the modification of ROMs.

The goal and thus the fascination of many ROM hackers is to change an existing video game according to their own ideas, to redesign and partly to create anew (or to translate it if the game has not been published in their own language). Games from various consoles are suitable for this as ROM. Game Boy Color and Game Boy Advance as well as NES and SNES games are particularly popular because they have easy-to-modify 2D graphics and relatively simple programming. On the Internet you can even find extra editors for some games. B. simplify the construction of a new level or changing various physical properties.

The most hacked ROM game to date is Super Mario World for the SNES. It is very popular with ROM hackers because of its simple programming and the large number of editors / tools .

ROMs that have been modified in this way are sometimes published as ROM itself, but this can be illegal as the ROM sometimes still contains old, copyrighted material. It is also possible not to publish the result of these changes and thus a ROM, but only the changes with a patch . The IPS patch is a widely used type .

ROM hackers use various tools to make editing the games easier. Since the ROMs are only files that consist of program code and other data and these are usually not available in common formats, translation tools are required. Graphics, music, etc. would be much too big if they were saved in the usual formats, which is why there are often only a certain number of colors available for graphics ( color palette ). More complicated change processes require special programs with which entire maps, worlds, game mechanics, etc. can be changed. These programs are provided by amateur programmers and can be used by all ROM hackers . Among other things, the following are used: a hex editor , graphics programs ( tile editors), decryption programs ( LZ77 ), assemblers and / or programs specially developed for certain games. A particularly complicated process is changing the game code using ASM . In machine language, all details can be changed at will, but it is often very difficult to use this language as it is very primitive and you have to understand the original code in order to use it effectively. Debuggers are also used for this because they can be used to trace code step by step and the ROM hacker knows exactly what to look out for.

In addition to the old SNES video games, newer games are also being tackled in order to either change them completely or to create cheats for so-called cheat modules (code hacking). One example of this is the Pokémon series from Gamefreak. Due to the versatile usability of the games, many ROM hackers also come up with new courses of action and other things for the video games. A large number of Internet communities have formed around the topic and are partly dedicated to the topic of Pokémon as an alternative to the old SNES games.

The Pokémon parts for the Game Boy Advance receive special attention , because they do not yet use the difficult-to-modify 3D graphics, but a system based on tiles. A large number of auxiliary programs make it easier to modify the games. The events that occur in the game can also be easily changed thanks to a script engine already installed by the manufacturer of the game and allow the game to be changed to such an extent that the original is difficult to recognize.

Web links

Individual evidence

  1. § 53 Reproductions for private and other personal use. In: juris BMJ. Federal Ministry of Justice, accessed on July 27, 2012 (German).
  2. One example of this is the Pokémon Sovereign of the Skies hack, which uses Pokémon Emerald as a basis to create a game that is significantly different from the original.