Spindle speed variation ssv for chatter control

Sir,
Here attached below is my .hal file. I cannot figure it out. Help me out, please.
 

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Just to add some more heads spinning potential in to the mix, with this extra gcode sugar being available you might want to look at options for editing  you CAM tools post processor to handle the enhanced spindle speed command.  The M100 and M101 should be just a matter of inserting custom gcode into CAM operation flow.  image missing /media/kunena/emoticons/devil.png

Before i started/stoped the speed variation from gcode subroutine, using M68 for parameter and M65 for reset. Then i felt i need the ability to live finetune the parameter, so it's integrated in the sidepanel now. Works fine.
As i wanted to keep programmed S as max. rpm , i was lowering the middleline of sine by half amplitude input, so the highest S is the programmed S.  S18000 at 10% set speed to 17100 and variation +-900.
Amplitude input % of S - for easier processing input from 0.01 to 0.2 - is smooth to apply by slider. Avoid big, unwanted jumps compared to input S, which can have a much wider range. When reset, i needed to make shure offset set back to initial speed. Good results with amplitude of 6%  and frequency from 0.5 to 1

 

I am thinking that I might want to add this to my lathe as a hardware switch. And chip-breaking too. (Z-axis offset)