The Turtle System

I’ve always been a huge fan of Logo as a way of teaching programming: not just the use of turtle graphics to provide immediate visual feedback, but also the way the structure of the language naturally leads students through key programming concepts as they learn how to draw increasingly complicated shapes.

So I was rather delighted whilst at BETT to discover Peter Millican’s Turtle System. Originally written with Pascal in mind, it’s now being developed to use a simplified version of Java to produce turtle graphics and more.

The system comes as a lightweight Windows exe (which runs perfectly fine on Linux under WINE) and a simplified browser based version.

To program in Java…

1. View|Display Power User Menu. Amongst other things, this will make the Language option appear in the menu bar
2. Choose Language|Java. This is the preliminary version. I notice that a Python and BASIC version are still to come.
3. Choose Help|Illustrative Java Programs to see some samples. Notice the simplified syntax in the main() method signature.

Sample Program

class drawPause
{
    void main()
    {
            colour(green);
            blot(100); //green blot
            pause(1000); //pause 1 sec
            colour(red);
            forward(450); //red line
            pause(1000);
            right(90); //90 degrees
            thickness(9); //thickness 9
            colour(blue);
            pause(1000);
            forward(300); //blue line
    }
}