Vtech Power Zone Edge User Manual - Page 33

LOGO This activity let you experience LOGO, which is a computer programming language. You can use LOGO to teach your VTECH® Power Zone™ Edge to draw. This system of drawing is called Turtle Graphics. COMMANDS Instructions to the Turtle are called commands. Each command begins with a key word telling the Turtle what to do. For example, "forward" is a command that tells the Turtle to move forward; "right" is a command that tells the Turtle to turn to the right. Often, commands will require additional information such as how far forward the Turtle should go. For example, "forward 10" tells the Turtle to move forward 10 steps; "right 90" is a command that tells the Turtle to turn 90 degrees to the right. If additional information is required for a command, it must appear immediately after the command, separated from the command by a space. In the home position, the Turtle is represented by an arrow at the center of the screen. This location is indicated with the pair of numbers (0,0). The first number of this pair indicates how far left or right the Turtle is from the center of the screen; it is called the x-coordinate. The second number indicates how far up or down the Turtle is from the center of the screen; it is called the ycoordinate. For example, the pair (10, -5) indicates that the Turtle is 10 steps to the right and 5 steps below the center of the screen. ROUTINES Additional commands can be created by defining new LOGO routines, For example, here is a LOGO routine to tell your VTECH® Power Zone™ Edge how to make a square: to square forward 10 right 90 forward 10 right 90 forward 10 right 90 forward 10 right 90 end Drawing a square consists of going forward and turning right four times. This can be written quicker by using a repeat command: to square repeat 4 [forward 10 right 90] end 25