Logo Arts

To New
  # set default screen, pen and turtle values
  ResetAll SetScreenSize [400 400] HideTurtle
  SetSC Black SetPC Green SetPS 1 PenUp
End

To Ring :Rep
  Make "Parity Minus :Parity
  Repeat :Rep [
    Make "PenC Abs :PenC -7 SetPC :PenC
    Forward 3*:Rep
    Left :Parity *18 Square 13 Right :Parity *18
    Back 3*:Rep Left 360/:Rep]
End

To Square :Side
  # square (side x side) drawn from centre (tp)
  Back :Side/2 Right 90 Back :Side/2 PenDown
  Repeat 4 [
    Forward :Side Left 90]
  PenUp Forward :Side/2 Left 90 Forward :Side/2     # r2c
End

To Go
  New
  SetSC LightGray SetPC White
  Make "Parity 1 Make "PenC 7
  ForEach "Rep [60 46 32 20] [Ring :Rep]
End