I'm writing up a description of the APU's voices, and I wanted to make sure my noise description was technically accurate:
This look OK?
Quote:
While the noise channel has its own frequency control like the pulses, the composer may only select from one of sixteen preset values. To produce noise, the channel relies on a continuous pseudo-random number generator (RNG) that outputs a repeating 32,767-bit sequence. Triggering the noise channel ‘taps’ into that stream in situ, meaning that two ‘identical’ noise notes are statistically unlikely to be the same. However, the noise is not truly random because its underlying bit sequence is finite and looped. The net effect is that altering the channel’s frequency alters the RNG stream’s playback rate and thus the perceived frequency content of the noise.
The noise channel had a second mode that would radically abbreviate the RNG’s output to only 93 bits, altering the channel’s standard percussive timbre to a metallic buzz. Third-partly developer Capcom in particular used it for sound effects in Darkwing Duck (e.g. dialog), Mega Man 2 (e.g. Metal Blade weapon), and Duck Tales (e.g., entering mirrors). But they also used metallic noise for several musical tracks, including Duck Tales’ traveling music, Code Name: Viper’s third level, and Mega Man 2’s Quick Man stage.
The noise channel had a second mode that would radically abbreviate the RNG’s output to only 93 bits, altering the channel’s standard percussive timbre to a metallic buzz. Third-partly developer Capcom in particular used it for sound effects in Darkwing Duck (e.g. dialog), Mega Man 2 (e.g. Metal Blade weapon), and Duck Tales (e.g., entering mirrors). But they also used metallic noise for several musical tracks, including Duck Tales’ traveling music, Code Name: Viper’s third level, and Mega Man 2’s Quick Man stage.
This look OK?
