Those of you who were around at Comdex 1989 will remember this TT demo 
from Atari Corp.  It was one of the first and still is one of the most
colorful.  It uses any NEO pictures it finds lying around the
directory, so you can customize it to a degree.

Set your TT in TT Low and start DIAG in the same folder with the NEO 
pictures.

Keystroke commands: 

F = fuji toggle
N = Toggle NEO window display
0 (fast)- 9 (slow) speed of color scrolling
space bar = stop scrolling background
d = direction of color scrolling
ESC = quit