[taken from the official readme]

0xx - arpeggio (second tone halfsteps, third tone halfsteps) change speed in settings:Arp xx.

1xx - arpeggio speed (speed, speed) use one of the values or both multiplied.

2xx - delay (speed, feedback)

3xx - portamento (speed, speed) uses a single value if other is 0 or a multiplication of 
both. Sets the speed to when new notes will be reached.

4xx - vibrato (speed, depth).

5xx - distortion (amp, amp).

6xx - FM (depth, speed).

7xx - detune (amount, amount) 88 is middle.

8xx - PWM (linear position/oscillation depth, oscillation speed) on squarewave. If 
param2 is present, param1 will be used for osc depth.

9xx - set wavetable/waveform for current channel. param1: set wavetable lane 0-5 
or param2: change waveform 0-5.

Axx - (left amplitude, right amplitude) can be used for amplitude, pan and turning 
off a tone.

Bxx - downsample sweep down (linear, sweep) Works best on noise channel. 
Choose either linear or sweep.

Cxx - downsample sweep up (linear, sweep) Works best on noise channel. Choose 
either linear or sweep.

Dxx - ends pattern. D11 - jump to next pattern and reset tempo seq. D1x - reset 
tempo seq. D2x - switch tempo_seq column. x = tempo seq column (0-5).

Exx - pitch up (fast, slow) Works on non-noise channels. Both values can be 
combined to increase effect.

Fxx - pitch down (fast, slow) Works on non-noise channels. Both values can be 
combined to increase effect.

Gxx - bitcrush, params are multiplied to represent a bit depth. Affects all channels.