Series of know issues articles are showing known issue itself about Small Basic and it's workaround.


Turtle.Show() after GraphicsWindow.Clear() or Turtle.Hide() doesn't show Turtle again.  Because of this issue, there is no official way to remove Turtle pen drawings (trails) and to draw with Turtle again.

Reproduction Requirements

This issue can be reproduced with:

  • Small Basic 1.1 or before


There are two ways to avoid this issue.

  • Don't use GraphicsWindow.Clear() and Turtle.Hide().
  • Use Shapes.HideShape("_turtle") instead of Turtle.Hide().
To remove Turtle pen drawing (trails), there are three ways.
  • Call Turtle.PenUp() and use Shapes.AddLine() instead of the Turtle pen drawings.
  • Redraw with Turtle and the same pen color with background color.
  • Use Shapes.Remove("_turtleLine" + n) to remove Turtle pen drawings.  The detail is described here.

Sample Programs

  • Turtle Show after Clear FLR412 - This program reproduces this issue.
  • Turtle Show after Hide LCZ614 - This program reproduces this issue.
  • Remove Turtle Trails GXH926 - This program is a workaround to remove Turtle pen drawings (trails).

Related Resources

See Also