# Main Command: Go
# Spiral by Guy Walker
# www.logoarts.co.uk

to new
  # set default screen, pen and turtle 
  ResetAll SetScreenSize [400 400] HideTurtle 
  SetSC Black SetPC Green SetPS 1 PenUp 
end

to go
  New
  SetSC LightGray
  For [X 5 175 15] [
    Make "NewRadius 10+90*(1+Cos :X)
    SetPC White SetPW 1 Circle :NewRadius FillZone
    SetPC Black Right 6*PenWidth SetPW (:NewRadius/7)-2
      Repeat 18 [
      PenDown Forward :NewRadius-(PenWidth/2) 
        PenUp Back :NewRadius-(PenWidth/2) Left 20]
    SetPC Gray SetPW 1 Circle :NewRadius ]
end