Here is a little program which will draw EXTRAHALFBRITE plasma cloud
fractals.  Plasma clouds are drawn by an algorithm which picks colors
of the corner of a rectangle (the whole screen to start) then continues
recursively quartering the rectange until it is 1 pixel.  Random colors
are averaged with respect to the other rectangles in such a way that
small neighborhoods do not show much color change.  

Pressing C key at any time begins color cycling the clouds
press any key to stop color cycling.
Menus are active while drawing.
Pressing any key except C while drawing results in a pause.

These should really be done in HAM mode but I had trouble mapping
things in that mode so I punted. I have a "virtual" palette of
256 colors which I map to the non contiguous EHB palette 
(I assume all shades of a color are contiguous) hence
the maparray and the unmap macro.

EHBPlasma020 is for 68020 machines only
EHBPlasma is for all amigas.

Enjoy!

Roger Uzun
9733 Roe Drive
Santee, Ca. 92071
bix: ruzun