Ms. PacMan & General Computer
Atari vs. Nintendo: The Reversal of Reverse Engineering
"Within the computer game world, it has been substantially shown that simply being compatible with a system does not show copyright infringement. In "Galoob vs Nintendo" , the Game Genie by Galoob was shown not to infringe on Nintendo's copyrighted system which it altered. In "Sega vs. Accolade", the Sega-compatible games by Accolade, Inc. were shown not to infringe on Sega games. Connextix has similarly made products usable with other games successfully, with court decisions to back them up.
The key in these cases is that the compatible games did not reproduce
substantial portions of the original game code. In contrast, "Atari
vs Nintendo" found that Atari's Nintendo-compatible games did
copy verbatim large portions of the original code (which they obtained
through surreptitious means), and were found to have violated copyright."
