diff --git a/lpst.pl b/lpst.pl
index f06f01f..c4d310e 100644
--- a/lpst.pl
+++ b/lpst.pl
@@ -206,15 +206,21 @@ my $EMPTY_CELL = 900;
 my %board;
 
 
-sub disp_1(){
-    return $HEX_1
+# Display lines
+#==================================================
+
+sub disp_1($$){
+    my ($r0, $c0) = (shift, shift);
+    return $HEX_1;
 }
 
-sub disp_2(){
-    return $HEX_2
+sub disp_2($$){
+    my ($r0, $c0) = (shift, shift);
+    return $HEX_2;
 }
 
-sub disp_3(){
+sub disp_3($$){
+    my ($r0, $c0) = (shift, shift);
     return $HEX_3;
 }
 
@@ -232,12 +238,15 @@ sub disp_y_axis($$$$){
     return ($s0, $s1, $s2);
 }
 
+# Display cell
+#==================================================
+
 sub add_cell($$$$$){
     my ($s0, $s1, $s2, $r0, $c0) = @_;
     
-    $s0 .= disp_1();
-    $s1 .= disp_2();
-    $s2 .= disp_3();
+    $s0 .= disp_1($r0, $c0);
+    $s1 .= disp_2($r0, $c0);
+    $s2 .= disp_3($r0, $c0);
 
     return ($s0, $s1, $s2);
 }
@@ -249,7 +258,10 @@ sub disp_0($){
 
     $r0 = shift;
 
+    # Append the y axis
     ($s0, $s1, $s2) = disp_y_axis($s0, $s1, $s2, $r0);
+
+    # Iterate through the cells
     for my $i (1..11){
 	($s0, $s1, $s2) = add_cell($s0, $s1, $s2, $r0, $i);
     }
@@ -257,6 +269,9 @@ sub disp_0($){
     return $s0."\n".$s1."\n".$s2."\n";
 }
 
+# Display row
+#==================================================
+
 sub disp_row($){
     my $row;
     my $r0;
@@ -264,6 +279,8 @@ sub disp_row($){
     $r0 = shift;
 
     $row = disp_0($r0);
+
+    # Handle trailing characters
     if($r0 % 2 == 1){
 	# Trim the start of the first line
 	$row =~ s/$TRAIL_1/ /;
@@ -277,19 +294,6 @@ sub disp_row($){
     return $row;
 }
 
-sub disp_x_axis(){
-    my $s0;
-    
-    $s0 = $PAD_AXIS;
-    $s0 .= join(
-	$PAD_AXIS, map{
-	    $AXIS_RV{$_}
-	}(1..11));
-    $s0 .= "\n";
-    
-    return $s0
-}
-
 sub disp_trailing_row(){
     my $s0;
     my $s1;
@@ -314,6 +318,22 @@ sub disp_trailing_row(){
     return $s0;
 }
 
+sub disp_x_axis(){
+    my $s0;
+    
+    $s0 = $PAD_AXIS;
+    $s0 .= join(
+	$PAD_AXIS, map{
+	    $AXIS_RV{$_}
+	}(1..11));
+    $s0 .= "\n";
+    
+    return $s0
+}
+
+# Display board
+#==================================================
+
 sub disp_board(){
     my $b;