Parametric Space Surfaces for the TI-89 v1.0    By: Jake Griffin

This TI-BASIC program is the first of its kind.  It uses 3d drawing routines
to draw a parametrically defined 3d space curve!  This program is a MUST HAVE
for ANYONE studying 3D equations!!  See screen shots for examples of what
this program can do!

2.08 and later: Send "Parm3d 2.08+" to your calculator
Prior to 2.08 : Send "Parm3d" to your calculator

Initially, the program may be sent to a folder named "math" but it is not
necessary to keep it there...put it wherever you wish, archived or not.

Type 'Parm3d()' to start the program
At the first dialog box, it will prompt for x(u,v) y(u,v) z(u,v) eye(theta)
and eye(phi).  x, y, and z are the parametric equations, and the "eyes"
work the same as in 3d graphing.
At the second dialog box, it will prompt for umin, umax, ustep, vmin, vmax,
and vstep.  Yep, you guessed it.  These are the lower, upper, and step for 
'u' and 'v' (same as tmin tmax and tstep in the built in parametric graphing).
Once you have input all the information, press enter and it will graph the
function. Voila!

Note: currently, the program has "default" values for graphing.  These make
the helix-like shape shown in "pic1.gif" which was included in this zip file

History:
  *  v1.0  FIRST RELEASE TO TICALC.ORG


Future plans:
  *  Add a "save" feature that saves and compresses your previous inputs
  *  Possibly add the third 'eye' variable
  *  Add the ability to rotate the graph. May have to port to C(speed reasons)
  *  Add a "zoom in/out" feature