text: # SPDX-FileCopyrightText: 2019 John Edgar Park for Adafruit Industries
  #
  # SPDX-License-Identifier: MIT
  
  # Turtle Gizmo Parabolic Jack
  #==| Turtle Gizmo Setup start |========================================
  import board
  import busio
  import displayio
  from adafruit_st7789 import ST7789
  from adafruit_turtle import Color, turtle
  displayio.release_displays()
  spi = busio.SPI(board.SCL, MOSI=board.SDA)
  display_bus = displayio.FourWire(spi, command=board.TX, chip_select=board.RX)
  display = ST7789(display_bus, width=240, height=240, rowstart=80,
                   backlight_pin=board.A3, rotation=180)
  turtle = turtle(display)
  #==| Turtle Gizmo Setup end |=========================================
  
  print("Draw parabolas using straight line segments!")
  
  def vert(x, y, size):
      turtle.goto(x, y)
      turtle.dot(size)
  
  turtle.penup()
  turtle.pencolor(Color.GREEN)
  
  vert(0, 0, 7)
  vert(0, 100, 7)
  vert(100, 0, 7)
  vert(0, -100, 7)
  vert(-100, 0, 7)
  
  x_quad=[10, 10, -10, -10]
  y_quad=[10, -10, -10, 10]
  
  for q in range(4):
      for i in range(0,11):
          x_from = 0
          y_from = (10-i) * y_quad[q]
          x_to = i * x_quad[q]
          y_to = 0
          turtle.penup()
          turtle.goto(x_from,y_from)
          turtle.pendown()
          turtle.goto(x_to,y_to)
  
  turtle.home()
  
  
  while True:
      pass
  