

They are 3D object files for CAD 3D 2.0, a program written by Tom Hudson
for the Atari ST computers.  Don't know much more about them except that
they are stored with the points first, then the surfaces are next, and are
made by listing 3 point numbers that make up the triangle surface. Then
there's a header that describes coloring, lighting, etc.  Don't know much
more than this, hope this helps.