Does the Turtle speed up in Turbo Mode or just jump to random positions? 1) Green Flag to run at normal speed. 2) Hold <Shift> key and click "Green Flag" to put Scratch into Turbo Mode. The turtle seems to jump all over the screen. 3) <Shift> key and "Green Flag" to put Scratch back into Normal Mode. 4) Press <Space> key for Pen Down and the Turtle leaves a trail. 5) <Shift> and "Green Flag" to put Scratch into Turbo Mode once more. Now you can see the pattern created by the path that the Turtle has travelled along. Brief Explanation ----------------------- In Normal Mode, the Turtle moves 5 pixels in the loop and is then displayed every 1/30th second. In Turbo Mode, the loop may repeat over a thousand times before 1/30th second has elapsed and it is time to redraw the screen. The loop has repeated so many times that the Turtle can have moved pretty much anywhere on the screen and its movement looks random. When the Pen is Down, the Turtle leaves a trail as it moves. In Turbo Mode the Pen draws as the Turtle races around, but the drawing is only updated to the screen every 1/30th second.
* See this tutorial for more on Turbo Mode, also "run without screen refresh" custom blocks, how Scratch runs and how to structure projects: https://scratch.mit.edu/discuss/post/3680379/ * Huge thanks to @PinkyPepper for the Turtle picture.