anchor.diff:    (endwin))
   
   (defun nctest2 ()
  +  "Save and use the screen pointer, set attributes by their bitmask."
     (let ((scr (initscr)))
       (mvaddstr 0 0 "hello there")
       
  
positive.code:     
      (addch (char-code #\a))
      (addch (char-code #\b))
      (addch (char-code #\space)) ;; trying to write space will actually write the background char #\.
      (addch (char-code #\space))
      (addch (char-code #\c))
      (getch)
  
negative.code:     ;; (erase) and (clear) use the last bkgd char to overwrite the window.
      (clear)
      (getch)
  
      ;; here we only set a color as the bg char, the default bg char is space
      (bkgdset (color-pair 2))
      (addstr (format nil "bkgdset: green on white~%"))
      (getch)
  
      ;; the default color pair is black on white
      (bkgd (color-pair 0))
      (addstr (format nil "bkgd: default colors~%"))
      (getch)
  