First Steps; Dr. Logo Procedures - AMSTRAD cpc 6128 User Instruction

First Steps ....
The? prompt tells you that Dr. LOGO is waiting for you to type something at the
keyboard.
Try typing in (using lower case letters):
fd 60
.... and you will see a turtle (a large arrow head) appear, which then moves forward 60
units leaving a line behind it from where it started, to where it finished. The screen
will clear giving a large graphics area and a smaller text area with the? prompt near
the bottom ofthe screen.
Dr. LOGO will often decide to re-arrange the screen so as to give either a large text
area or large graphics area, for your convenience.
Type in:
rt
90
.... and the turtle will move 90 degrees to the right.
Now type in:
fd 60
.... and another line will be drawn the same length, at right angles to the first line.
Experiment with the simple instructions f d, b
k
(short for back), r t and
L
t (short
for left) to see what happens on the screen.
Dr. LOGO Procedures
A procedure is a list of instructions that tells Dr. LOGO how to do a task.
You will probably write your first procedures by adding to those already built into Dr.
LOGO, these are called 'primitives'.
f d, b k, r
t
and
L
t
are all built-in primitives which you may use at any time as
building blocks to write your own procedures.
Another very useful built-in primitive is cs which clears the screen and sends the
turtle to its starting position.
Introduction to Logo Chapter 6 Page 3