AY8930 instrument editor

AY8930 instrument editor consists of these macros.

[Volume] - volume sequence
[Arpeggio]- pitch in half-steps
[Noise Freq] - AY8930 noise generator frequency sequence
[Waveform] - selector of sound type: pulse wave tone, noise or envelope generator
[Pitch] - fine pitch
[Phase Reset] - trigger restart of waveform
[Duty] - duty cycle of a pulse wave sequence
[Envelope] - allows shaping an envelope
[AutoEnv Num] - sets the envelope to the channel's frequency multiplied by numerator
[AutoEnv Den] - sets the envelope to the channel's frequency divided by denominator
[Noise AND Mask] - alters the shape/frequency of the noise generator, allowing to produce various interesting sound effects and even PWM phasing
[Noise OR Mask] - see above