This file is a semi-copy of the "Galaxies in Collision 3D" by Michael 
C. Schroeder and Neil F. Comins, from ASTRONOMY Magazine, December 1988 
issue.
     It is written in BASIC for GWBASIC and works under that. As to other 
BASICs, I don't know. On my computer running slow it takes awhile between 
each display (well not that long...) however things look pretty good within 
200 steps. (often within 50).

     GALAXY.BAS is pretty close to the straight, out of the magazine REMs 
and all program.

     In response to the initial questions I use:
          # of rings: 10 - 20
          # of stars/ring: 10 - 20      { rings * stars <= 1000 }

The more stars and rings you have the greater you can see the tidal 
effects. Slows you down abit... So use your higher speed!!

Result    Mass      x         y         z         vx        vy        vz
Ring      1.00      7.5       0         35        0         0        -1.0
Bridge     .25     40        10         10       -1         0         0
Whirlpool  .25    -30        30         0         0       -.34        .34

For more information read the article, and/or drop me a line on HAWAII 
SPACE CONNECTION.
     Have Fun                 Ted Brattstrom