NES Noise

Plays basically the same kind of noise as the Nintendo Entertainment System.

See: 
http://en.wikipedia.org/wiki/Linear_feedback_shift_register
http://nesdev.parodius.com/NESSOUND.txt

by shaktool 19 Jan 2012

Embed

/**
 * Copyright shaktool ( http://wonderfl.net/user/shaktool )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/mccJ
 */

package {
    import flash.display.Sprite;
    import flash.events.SampleDataEvent;
    import flash.media.Sound;
    
    [SWF(width='320',height='240',frameRate='255',backgroundColor='0xFFFFFF')]
    public class FlashTest extends Sprite {
        public function FlashTest() {
            var buffer: int = 1;
            var timeUntilReset: int = 0;
            var rate: int = 1;
            function onSampleDataEvent(event: SampleDataEvent): void {
                for (var i: int = 0 ; i < 2048; i++) {
                    if (timeUntilReset == 0) {
                        timeUntilReset = 44100;
                        rate *= 2;
                        if (rate > 200) rate = 1;
                    }
                    timeUntilReset--;
                    if (i%rate == 0) {
                        var newBuffer: int = buffer >> 1;
                        if ((buffer + newBuffer) & 1 == 1) {
                            newBuffer += 1 << 14;
                        }
                        buffer = newBuffer;
                    }
                    
                    var sample: Number = buffer & 1 ? 0.1 : -0.1;
                    event.data.writeFloat(sample);
                    event.data.writeFloat(sample);
                }
            }
            
            var sound: Sound = new Sound();
            sound.addEventListener(SampleDataEvent.SAMPLE_DATA, onSampleDataEvent);
            sound.play();
        }
    }
}