The Sid Chip – or the 6581/8580 Sound Interface Device, shipped with the Commodore 64 and 128 amongst others and was (and some might say, still is) responsible for some of the most unique and innovative computer music created.
During the 8-bit era, it truly stood out amongst its competitors and was clearly streets ahead in terms of the diversity of sound it could generate. The American engineer who created the chip, Robert Yannes, commented;
I thought the sound chips on the market, including those in the Atari computers, were primitive and obviously had been designed by people who knew nothing about music.
Robert Yannes, On the Edge: The Spectacular Rise and Fall of Commodore
There’s a really interesting interview with Robert here detailing the thinking and eventual production behind the chip, despite Robert’s ambitious aspirations for the chip, it makes it almost seems like a rushed experimental accident.
But this is what made the chip so unique; an understanding of what creative musicians needed and could innovate with. Despite being fairly unhappy with the intital launch (it was intended to have 34 voices but ended up with 3) it was still well ahead of anything else out there; each of the 3 voices had a unique oscillator capable of producing four different waveforms – those being square, triangle, sawtooth, and noise. Added to that were a variety of modulation filters that could be applied, giving a fairly wide scope of options for a computer musician back then. In fact, the unique sound is still popular and in use today with a vibrant scene of emulators and SID chip musicians still going strong.
You can read more of the technical details behind the chip at wikipedia.
Robot Elephant recently released a great compliation of 8-bit game tunes, featuring some of the innovators and talents of the era that took the chip’s capabilities and pushed it to the max; Ben Dalglish, Rob Hubbard and Martin Galway, to name a few.
What’s more incredible is the technique in which the early music was created – there were no cubase-like sequencers or sound libraries back then; most of it was done in Assembly. You’ll still hear the unique chip-tune sounds of the SID in music today. There’s a thriving emulator and archive scene, not to mention musicians still using the hardware and producing music exclusively with it. The sound never seems to date and has become an iconic piece of technology and creative musical art.