Hypocycloid is essentially an electronic Spirograph inspired by the article
Five Original Graphics in February 1984 BYTE.  Also, see articles in
May-June 1984 Creative Computing for background on the hypocycloid and basic
formula for drawing these.

About the menus. . .

The main menu:

'New' prompts the user for new values for large and small radii.
'Go' begins the iteration process and continues to draw until either stopped
with 'Stop' or 360 degrees of rotation or 360 iterations are drawn,
whichever comes first. Go initiates a new series of iterations without
going back to where 'stopped', so note the finality of 'stop', colorwise
anyways--you can always start the same series over with a different color
table.
'Stop' stops the iteration process midstream without completing current
iteration (hold menu down alternately before selecting 'stop' to complete
iteration before stopping -- I tried the other way -- letting the iteration
complete before stopping and the loop got too confusing to work correctly--
couldn't tell when the loop ended and so on.)
'Save' saves drawing in iff.ilbm format, uncompressed, each picture taking
about 40k disk space.
'Quit' exits program.

Reduce:

The ratio of reduction of the first iteration to the last iteration, 1.0
being 100% reduction. That is, the final iteration of the hypocycloid will be
100% smaller than the first iteration. Default at beginning of program is 0,
no reduction.

Begin:

(Hard to explain) The beginning reduction factor as part of the reduction
ratio.  Increasing this produces more circular patterns or curls in the ends
of the hypocycloid.  Starting at 0 makes the hypocycloid more pointed.
Default is 0.

End:

The end reduction factor as part of the reduction ratio.  If less than the
beginning reduction factor, the result is a figure that grows outward
instead of inward (hard to believe, ain't it?). Experiment with this and the
others! Default is 0.

Angle:

The angle of rotation where each iteration is offset from each other by this
amount. Takes more rotation to produce significant displacement of the
figure when the reduction factor is under 1.0. Default is 0. Unless you set
the reduction factor to something besides 0 and the angle was 0, the figure
would continue to draw the same figure in the same place only with different
colors (when 'go' is chosen from the main menu).

      Terry W. Gintz
      2841 Adams St
      Alameda, CA 94501