POOL is a machine-language pixel graphics demo based on an idea by Ken Marks (see "Designer Screens" in the June 84 issue of 80 Micro). You watch the path of a perfectly elastic pool ball as it bounces around a rectangular table, two gimmicks give the resulting graphics surprising complexity:
1) While the ball moves in the upper left quadrant, mirror images of it also move simultaneously in the other three quadrants. When the quadrants overlap the resulting interference patterns can be astonishing, you choose the size.
2) The balls flip the pixels in their paths, that is they turn "ON" pixels off and vice versa.
CAUTION: POOL is written for the M100 / DO NOT attempt to use it on the M200!
POOL is a Basic program, just run it and respond to the prompts. It creates a machine-language subroutine below HIMEM so it should not interfere with other machine-language programs. The following keys are active:
"ESC" to return to the Basic.
"S" (lowercase) to freeze the display, the display will remain frozen until you hit "s" again or "ESC" to Basic.
"1-9" to change speeds while the balls are in motion. Speed 1 is the slowest and is just a CRAWL, speed 9 is really too fast to follow. The speed roughly doubles from one number to the next, the program begins at speed 6.
Hint: Choose the table dimensions so that the quadrants overlap, it helps to make the horizontal dimension almost one multiple of the vertical dimension.
Some of my favorite patterns:
150-63-39-13 152-63-13-39 155-63-39-13 and especially 131-43-anything-anything.
