anchor.diff:                (loop for i from a1 to a2 do
                      (loop for j from 0 to 5 do
                           (loop for k from 0 to 2 do
  -                             (echo scr #\space
  -                                   :y (+ 3 j (* n 7))
  -                                   :x (+ (* (- i a1) 3) k a3)
  -                                   :color-pair (list :black (+ (* n 108) i (* j 6)))) )))))
  -
  +                             (echo-wide-char scr #\space
  +                                             :y (+ 3 j (* n 7))
  +                                             :x (+ (* (- i a1) 3) k a3)
  +                                             :color-pair (list :black
  +                                                               (list :number (+ (* n 108) i (* j 6)))) ))))))
       ;; 232-255: 24 shades of gray, without black and white
       (loop for i from 232 to 255 do
            (loop for k from 0 to 2 do
  -              (echo scr #\space :y 17 :x (+ (* (- i 232) 3) k) :color-pair (list :black i))))
  +              (echo-wide-char scr #\space
  +                              :y 17
  +                              :x (+ (* (- i 232) 3) k)
  +                              :color-pair (list :black
  +                                                (list :number i)))))
   #|
       (loop for i from 16 to 21 do
            (loop for j from 0 to 5 do
  
positive.code:     (loop for i from 0 to 7 do
           (loop for j from 0 to 1 do
                (loop for k from 0 to 2 do
                     (echo scr #\space :y j :x (+ (* i 3) k) :color-pair (list :black (+ i (* j 8)))) )))
  
      ;; 16-231: 6x6x6 color cube
      (loop for n from 0 to 1 do
           (loop
  
negative.code:                    :x (random width)
                     :color-pair (list :black (nth (random 7) colors))))))))
  
  ;; it is just a coincidence that "echo" works here.
  ;; echo is a chtype-function, and chtype allows only 1 byte for color pairs, which means 256 color pairs.
  ;; it works only because the foreground color is always black in the example.
  ;; echo-wide-char has to be used.
  (defun t20a ()
    "Display the 256 supported colors. This only works with TERM=xterm-256color in xterm and gnome-terminal."
    (with-screen (scr :input-echoing nil :input-blocking t :enable-colors t :cursor-visibility nil)
  