Phaser3 - ZX Spectrum beeper music engine
Original code and 1tracker version by Shiru 07'15



Two channel engine with two channel of phasing synth with 99 
customizeable instruments and 8 customizeable sampled drums. 

The phasing synth is a more advanced version of that in Phaser2. 

Phase reset is now performed in the instrument rather than the track, 
with option to reset phase to a given value or run the phase freely. 
There is new a parameter, phase slide, that slowly gets phase of both 
generators equal to each other (only possible when Detune=0); lower 
value means faster slide. This allows to create sound similar to the pin 
pulse engines, by setting mix mode to XOR, phase to a low value, like 
8-16, and phase slide to some value. 

Another new parameter is a virtual volume. It is a bit mask, so despite 
there are 16 possible values, only 1, 3, 7, and 15 create new volume 
levels. It brings a very noticeable carrier tone, though, so this 
feature has very limited use. 

There are two more new parameters, a separate tone slide for both 
generators. It has a limited range of -4 to 4 (fastest down to no slide 
to fastest up), and no limits on the upper and lower boundaries, so the 
sound has to be stopped manually. 

Engine uses sampled drums that can be imported from WAV files. 


The columns are:

Sp T1 I1 T2 I2 D
.. ..... ..... .
   |   | |   |
   +ch1+ +ch2+
   
Sp : Speed, 1..99

T1,T2 : Tone channels
 Tn : Note, C-0..B-9
 In : Instrument number, 1..99
 
 D : Drum, 1..8
