Contribute correction: MSX GRAPH-SCAN

  _  _     ______   ______    _    _   
 | \| ||  /_   _// |      \\ | || | || 
 |  ' ||   -| ||-  |  --  // | || | || 
 | .  ||   _| ||_  |  --  \\ | \\_/ || 
 |_|\_||  /_____// |______//  \____//  
 `-` -`   `-----`  `------`    `---`