20 years ago next month, Microsoft’s Xbox console debuted – and there’s a story behind how it got its unique boot sound sequence. Call it this century’s first chip music composition / sonic branding feat.

The latest version of this tale comes from Xbox Design Team’s Brian Schmidt, who this week wrote up the process:

Creating the Original Xbox Boot Sound: Using “old school” game audio techniques in a modern console

Everything that goes around comes around, in that there’s a fresh wave now of interest in revisiting that kind of sound technique on chips. (See, for instance, the latest Plogue stuff.)

Once it was booted up, of course, even that first-gen Xbox offered composers and sound designers power to spare. But while it was booting was another story – you’ve got 8 seconds and 25 Kilobytes of memory, so this amounted to a demoscene kind of task.

While the sound chips on systems from Sega and Nintendo are widely known, Microsoft had one in their console, too – from the unlikely vendor NVIDIA. (Yeah, the graphics NVIDIA.) That’d be the MCPX, a dedicated 256-voice sound chip with extra decode capabilities (via Dolby), plus a programmable filter and DAHDSR. Its alias: “SoundStorm.” And yeah, modders have gotten into its ROM.

In order to squeeze what would sound like full-quality audio out of this synth chip, the team had to give up 24-bit 48K sound and go distinctly lower-fidelity, calling up not only earlier game consoles but also the first digital samplers and wavetable instruments:

By downsampling the sounds to a horrifyingly low 6kHz sampling rate, I was able to squeeze the 3 very short sounds into the 25k: a thunder sound, a cannon attack and the attack portion of a glockenspiel. To increase the high end of the low-fidelity samples, I wrote some code to resample them to 48Khz, and deliberately distort them via clipping, which sort of worked. I was also able to create a 4th wave: ‘reverse thunder’ by using code to reverse the thunder sound in memory. You can hear the reverse thunder as part of the lead-in to the big green flash about 6 seconds in.

Looks a bit like this escaped from a livecoding event.

The whole article is a great read, even if you’re not a Halo superfan or something – as it might also make you go experiment with digital samples or livecoding and other tricks.

There’s a video on the topic, too, also featuring Brian. Enjoy: