NES Sound Format

NES Sound Format

NSF is the Filename extension of the audio file format originally designated as NESM (Nintendo Entertainment System Music) by the inventor Kevin Horton. This format was originally designed for playback in a custom hardware device named HardNES by the inventor. Over the years, the NSF format has been implemented for playback on many platforms via plugins, stand-alone players, emulators and also the NES PowerPak.

The particulars of the NSF format resemble the SID format loosely, where a header is prepended and then the original audio data follows. The original audio data commonly has been extracted from a ROM image or disk image and then modified for stand-alone playback by various players. The original audio data is also commonly referred to as an audio driver or music engine. The audio driver is then completely isolated from the rest of the code, data and graphics that have nothing to do with the audio driver. A complete NSF is considered a multiple song and sound effect container for one particular game or composition.