ROM ( Read-Only Memory, dt -only memory, or read-only memory ) is a common term for memory dumps of memory chip ( EPROM), in the games memory plug-in modules - also called Cartridges - were installed; they contain the data information of the actual game. Using emulators can be used these images on your PC or even played with writable plug-in modules for the most part back on the original console. Images of console games to CD or DVD are usually called ISO or image. When disk image is spoken by disc.
The possession and use of emulators is basically legal. However, some emulators need to run the ROM BIOS of each device, which in principle can not be delivered with the emulator. The legality of ROMs determined by appropriate regulations by laws to protect copyrights. If ROMs are not obtained from the copyright holders, in particular the nature and circumstances relevant to the legality, under which the copy was created. In Germany attacks § 53 ( reproductions for private and other personal use ) of the Copyright Act.
In addition to commercial ROMs there are also the homebrew scene, which deals with mostly unauthorized programming of external systems. There are, for example, programmers who are unlicensed develop on consoles and handhelds, and their products are available as freeware on the Internet. Legally, this is ( in Germany ) is not illegal, it is, however, a gray area. The final products are often used as ROM and can be played with appropriate hardware or emulators.
Target and thus the fascination of many ROM hackers is to change an existing video game according to their own ideas to remodel and create some new ( or even translate the game should not have been published in their own language ). To this end, various games consoles are as ROM. Are particularly popular Game Boy Color and Game Boy Advance and NES and SNES games, as they have an easy-to -modifying 2D graphics and a relatively simple programming. The internet address for some games even extra editors that simplify the construction of a new level, or changing various physical properties, for example.
The date usually chopped ROM game is Super Mario World for the SNES. It is due to its ease of programming and the large number of editors / assistants in ROM hackers very popular.
Will be published in such modified ROMs partly as ROM itself, but this may be illegal, since the ROM still partially includes old, copyright -protected material. It is also possible not to publish the result of these changes, and thus a ROM, but only the changes with a patch. A widely used type is the IPS patch.
ROM hackers use what is easier to design a wide variety of tools to edit the game. Since the ROMs are only files which consist of program code and other data and they do not usually exist in popular formats, translation tools are needed. Graphics, music, etc. would be much too large, if you would store it in the usual format, so stand for graphics often only a certain number of colors available (color palette ). More complex change processes require specialized programs, with which then all the maps, worlds, game mechanics, etc. can be changed. These programs are provided by hobbyists are available and can be used by all ROM hackers. Used to be so, among other things: a hex editor, graphics programs ( Tile editors ), decryption programs ( LZ77 ), assembler and / or programs developed specifically for certain games. A particularly complicated procedure is the change of the game code using ASM. In the machine language all details can be changed at will, but it is often very difficult to apply this language, as it is very primitive and one must also understand the original code in order to use them effectively. This also debugger can be used, because they can code step by step and follow the ROM hacker knows exactly what to look for.
In addition to the old SNES video games and newer games to be tackled in order to change either entirely or to create cheats for so-called cheat modules (code hacking). An example of this is the Pokémon series of Game Freak. Due to the versatility of games, many ROM hackers have new courses of action and another for video games come up. A variety of online communities have formed around the subject and devote himself partially to the subject of Pokémon as an alternative to the old SNES games.
A special attention get the Pokémon parts for the Game Boy Advance, because there the hard modifiable 3D graphics is not yet used, but a system based on Tiles system. A variety of support programs facilitates modifying the games. The events occurring in the game ( Events ) can be easily changed thanks to an already fitted by the manufacturer of the game script engine and allow it to change the game so far that the original is still very difficult to detect.