anchor.diff:  
   : fb8-toggle-cursor ( -- )
   	line# fb8-line2addr column# fb8-columns2bytes +
  -	char-height 2 - screen-width screen-depth * * +
  +	char-height 2 - screen-line-bytes * +
   	2 0 ?DO
   		dup char-width screen-depth * invert-region
  -		screen-width screen-depth * +
  +		screen-line-bytes +
   	LOOP drop
   ;
   
  
positive.code: 		fb8-columns2bytes swap fb8-columns2bytes tuck -
  		over r@ tuck + rot char-height 0 ?DO
  			3dup rmove
  			-rot screen-width screen-depth * tuck + -rot + swap rot
  		LOOP
  		3drop r>
  	THEN
  	char-height 0 ?DO
  		dup 2 pick fb8-erase-block screen-width screen-depth * +
  	LOOP
  	2drop
  ;
  
negative.code: : fb8-reset-screen ( -- ) ( Left as no-op by design ) ;
  
  : fb8-erase-screen ( -- )
  	frame-buffer-adr screen-height screen-line-bytes * fb8-erase-block
  ;
  
  : fb8-invert-screen ( -- )
  	frame-buffer-adr screen-height screen-line-bytes * invert-region
  ;
  
  : fb8-blink-screen ( -- ) fb8-invert-screen fb8-invert-screen ;
  