updated 11:35 pm EDT, Tue April 17, 2012
Patent awarded to Nintendo for gameboy emulation
The United States Patent and Trademark Office (USPTO) recently awarded Nintendo patent number 8,157,654 for emulating older handheld consoles. Specifically, Gameboy, Gameboy Color, and Gameboy Advance handhelds are targeted for emulation on external "low capability" computing devices such as airline seat-back displays. It's not immediately apparent what Nintendo plans on doing now that the patent has been awarded.
In nearly all cases, backwards compatibility on newer consoles uses either software or hardware emulation. Nintendo's patent covers both hardware and software emulation, but is specific to lower powered devices, rather than modern computers. Topics covered in the patent include frame-skipping to enhance performance, as well as requirements that the emulated software have a look and feel greater than or equal to the original hardware's execution.
Each major iteration of the Gameboy mentioned in the patent has a different processor. Backwards compatibility was generally limited to the generation just before the current model.
Global handheld emulation developed by Nintendo, such as addressed in the patent, would potentially open up a huge game back-catalog for usage on a wide variety of platforms -- not just Nintendo-produced ones. Nintendo has also been very publicly critical of independent emulator development. While not specifically addressed in the patent, Nintendo now has a level of legal protection that they did not previously explicitly possess.