Commodore VIC-20 User Manual page 66

I
You may want to experiment with this example some.
Press W/M to stop the wing flappings and change the upper
counting limit (150) in lines 2 and 4. Try changing just one
value, leaving the other at 150. Does your bird begin to soar?
Try a value like 50 in both places. Does your bird fly faster?
What about an upper limit of 500? 1000?
Hmmm...the bird gets rather s-l-o-w.
CLeaROut for HOME
You already know that you can clear the screen by holding
down IP^B and pressing the E3 key. From within
a program, you can tell the VIC to clear the screen. You do so
by typing:
print ■'
This character appears
when you hold
and press
<
c
c
c
c
<
c
When you are entering a PRINT message, if you press the two
keys ( ^^fl| and j^ ) that you use to clear the
screen, the reverse heart image appears on in the message
field. That symbol is a signal to the VIC that when the message
is PRINTed, the screen fs to be cleared at that place in the
message, and the cursor sent home. Home is the upper left-
hand corner of the screen.
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