Meet the turtle

Hello! In this book you will get to know a very special turtle. Here is a picture of him:

Here I am!

He's not a real turtle. He's a computer turtle.

The turtle wants you to help him draw things. He can't draw on his own. But he can draw very fast. He is a computer turtle, after all.

He has his own turtle language. This language is called Logo. It's different from your language. But it's not difficult to learn. Just open your Logo program (click here if you don't know how to do that) and write:

That tells the turtle to walk forward 100 steps. If you press "run" now, he will walk 100 steps. The turtle holds a pen towards the screen. He draws on on the screen when he walks.

Try writing other numbers. 100 steps is not so much to a computer turtle. You can also make him turn. Try writing:

RT 90 tells the turtle to turn to the right. Type LT 90 if you want him to turn left instead. (Note that there is always a space between the word and the number. LT90 doesn't work. LT 90 does.)

Sometimes when you tell the turtle to do things he makes a mess. Write CS to remove everything he has drawn. Write HOME to make him go back to where he started.

Turn page, or back to the table of contents.