Fast Action Graphics (Vector Animator) © 1980 Fabris, Robert.
Fast Action Graphics are demonstrated in this machine code background routine. Enter this program using your Blue Ram Utility and watch the Perkin's Engineering graphic (a PE) bounce around the screen without disturbing what is there!
The speed of motion is controlled by the #1 knob. Another special effect produced by this routine is a 'curtain of invisibility' at the top of the screen. As the graphic moves behind the curtain, it disappears one-half pixel at a time. The size of the curtain is also controlled by the #1 knob. Notice that you can still enter programs, etc. in BASIC because the graphic movement is performed in the background mode where it does not tie up the processor.
To Stop the background process from the foreground process using BASIC, enter:
:RETURN [GO].
To Start it up again, enter:
CALL 24576 [GO]
Published in ARCADIAN 2, no. 10 (Sep. 17, 1980): 101-102.
Programmer: John Perkins