The Super Nintendo Entertainment System's sound coprocessor, the S-SMP, runs on the mostly-forgotten SPC700 architecture. To understand why the sound of Super Metroid or SMW was so ahead of its time, we will look at all the details of how this processor works and how it plays music.
The SPC700 by Sony is an 8-bit architecture that was developed and used as the S-SMP sound coprocessor in the Super Nintendo Entertainment System (SNES). A big leap ahead in sound synthesis capabilities, apart from these few years of glory in the 1990s the architecture enjoyed no further uses and has faded into obscurity outside SNES circles. This talk not only takes a look at the SPC700 architecture, which is both a usual and unusual 8-bit ISA, but also the sound and music capabilities of the SNES S-DSP that it was designed to control. The talk is designed to be approachable by anyone with a basic understanding of how a microprocessor works; in particular, it covers the basics of digital audio necessary to understand the S-DSP's sound synthesis features like ADPCM sample playback or echo buffers.