MANDELBROT VER: 5.7, 11 Mar 1992

By H†kan Malmqvist
   AM elektronik
   Grevgatan 49
   S-114 58 Stockholm
   SWEDEN
   Tel + 46 (0)8 661 07 34
   Fax + 46 (0)8 663 20 34

To the Fractint people through
   Bert Tyler
   Tyler Software
   124 Wooded Lane
   Villanova, PA 19085
   USA
      
Hello everybody,

    This program has grown organically and unstructured from a small
kernal so it is really a mess. But when I saw your Fractint and compared
it to my program, I decided to share my efforts with you. 
    Especially the floting point assembler routine of mine I think is
pretty fast (something up to 3 times the Fractint floting point). I have
unrolled 4 iterations before making a comparison and all data stays in
the 80 bit accuracy of the stack. This allows zoomfactors up to 1E13 and
iteration depths of 10000 in times of 1-2 hours of some areas in the
Mandelbrot set.
    Also the color palette and the "Color Factor" I use tend to give nice
colors and a good compromise of exponentially changing color bands. The 
mouse came in late in the development so it is used only to place
and resize the zoom box.
    I was amused to find the idea of first generating a corse picture and
then fill in the details in a second pass also in Fractint. Originally
I had three passes with the second interpolating data from 9 of the 25
pixels in the first pass 5x5 box. I later skipped the second pass when
speed optimations made it unnessecary.
    Then came file saving with compression (2 pixels/byte in a run-length
format of my own), windows for making fast, small pictures, color cycling
with random generated colors, even frehand painting, and so on ... 
    So feel free to use the parts and ideas you like to include in your
Fractint as long as you give me credit for it.

Yours truly
H†kan Malmqvist



On the diskette:

README.TXT  Some explanations
MAND.BAS    Source code in Turbo Basic
XX.BIN      Inline assembler routines
XX.ASM      Assembler source routines
MAND.EXE    Executable file
XX.MDE      Sample Mandelbrot pictures