my(@board,$row,$col,$max_row,$max_col);
  $max_row = $max_col = 7;
  for($row=0;$row<$max_row;$row++)
    {
      $board[$row] = [];
      for($col=0;$col<$max_col;$col++)
        {
          # Fill out a square
          ${$board[$row]}[$col] = ??;
        }
    }