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Stop
Stop running the Logo program.
Step
This freezes the program so you can run it step by step. Press the step icon before
running the routine, then start the routine. Press the directional keys to see each step
performed.
Print the graphic.
COMMANDS
In the home position, the Turtle is represented by a arrow and sits at the center of the
screen pointing straight up. 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 also called the y-coordinate. 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.
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 (a quarter turn) 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.
ROUTINES
Additional commands can be created by defining new LOGO routines, For example, here
is a LOGO routine to tell your VTECH
®
SILVERSTREAK™ how to make a square:
The title “to square” – should be indented this way as well as the final line “end”. The
command lines should be single spaced. For example:
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:
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Summary of Contents for SilverStreak
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