When the SNES launched, one of its signature tricks was Mode 7, a graphics mode which allowed the console to rotate and scale backgrounds in hardware. This feature wasn't available on rival systems like the PC Engine and Mega Drive / Genesis, and it was used to good effect in games like F-Zero, Pilotwings and Super Mario Kart.
Given that its 16-bit rival wasn't capable of Mode 7 (that would have to wait for the Sega CD add-on), you wouldn't think that it would be possible on a console like the NES – but Something Nerdy Studios has achieved just that (kinda).
The indie developer is currently working on Former Dawn, an Action RPG for the NES and PC, and has just shown off footage of "Mode 7" working on original NES hardware.
As noted by the developer, this would have been possible even without the unique memory mappers it has developed, but the mappers take some of the load off the CPU.
Furthermore, while it can handle scaling to give the impression of perspective, it can't do rotation. "It's just a little bit beyond the design philosophy to implement rotation or scaling in hardware in our mapper, so we haven't done that," says Something Nerdy Studio. "This effect is more properly called 'fake HDMA', since that's the analogous part of the typical effect on the SNES."
Former Dawn's Kickstarter campaign launches today, so if you'd like to see this in the flesh, you might want to consider pledging some cash.