Contribute correction: MSX GRAPH-SCAN

           __   __               ___    
    ___    \ \\/ //     ___     / _ \\  
   /   ||   \ ` //     /   ||  / //\ \\ 
  | [] ||    | ||     | [] || |  ___  ||
   \__ ||    |_||      \__ || |_||  |_||
    -|_||    `-`'       -|_|| `-`   `-` 
     `-`                 `-`