GENERAL HELP
This program uses the idea of working in a single plane at a time 
and then being able to switch from plane to plane to get over the
problem  of getting a 3D output from 2D input.   There are  three 
available  modes  of view for input PLAN  (looking  from  above), 
ELEVATION (looking from the front) & LATERAL ELEVATION (from  the 
right hand side).  When you switch between modes any drawing that 
is  done is put in the plane that the keyboard driven cursor  WAS 
in before you switched.   So if you are in ELEVATION mode and you 
draw with the keyboard cursor or the mouse,  and then you  switch 
to  PLAN mode and move the keyboard cursor down the  screen,  and 
then  switch back to ELEVATION and continue drawing  these  later 
marks will be closer.  You can see this by selecting PERSPECTIVE.  
 
