Choose the command in the first column (up/down, x)
Change column (left/right)

Change the value in the second colum (x, then left/right to decrease/increase)
Delete instruction in the second colum with (o)

Have a look on i_core post to have more explanation about the language “I”.

I will make a tutorial soon and post a link and additional information here.

Sample 1 (gif)

:A 20 FD 90 TR ; :B 1 – # A ?B ; 4 B

Sample 2 (gif) made by roywig

You can accelerate the rendering process in the M:DRAW method. At the end, change from

self.vm:step()

to

i=4
while i>0 and self.vm:state()!=3 do
self.vm:step()
i-=1
end