daniel5151 writes: With a screen-resolution of just 256×240, the NES didn’t give games all that much screen real-estate to work with. Nevertheless, intrepid game developers squeezed amazing, iconic worlds into NES games: the maze-like dungeons of The Legend of Zelda, the sprawling planet of Metroid, or the colorful levels of Super Mario Bros.. And yet, due to the NES’s hardware limitations, gamers only ever experienced these worlds a single 256×240 viewport at a time… Until now.

Introducing: wideNES. A new way to experience NES classics.

As players move within a level, wideNES records the screen, gradually building-up a map of what’s been explored. On subsequent playthroughs of the level, wideNES syncs the action on-screen to the generated map, effectively letting players see more of the level by “peeking” past the edge of the NES’s screen! Best of all, wideNES’s approach to mapping games is totally generalized, enabling a wide range of NES games to work with wideNES right out of the box!

See the full article which discusses how this is done and to get the ANESE emulator.