Added some code to print out ASCIi characters in each word.

tools/sdump

@@ -12,12 +12,12 @@ use Fcntl qw(:flock SEEK_SET);
 ### return -1 on EOF
 sub read_word {
     my $F = shift;
+
     # Convert four bytes into one 18-bit word
     return -1 if ( read( $F, my $four, 4 ) != 4 );    # Not enough bytes read
     my ( $b1, $b2, $b3, $b4 ) = unpack( "CCCC", $four );
-    return (($b1 & 0xff)  |
+    return (
-            (($b2 & 0xff) << 8 ) |
+        ( $b1 & 0xff ) | ( ( $b2 & 0xff ) << 8 ) | ( ( $b3 & 0xff ) << 16 ) |
-            (($b3 & 0xff) << 16) |
           ( ( $b4 & 0xff ) << 24 ) );
 }
 
@@ -31,19 +31,32 @@ use constant WORDSPERBLK   => 64;      # 64 words per block
 use constant BYTESPERWORD => 4;       # We encode each word into 4 bytes
 
 # Skip the first surface
-seek($IN, NUMBLOCKS*WORDSPERBLK*BYTESPERWORD, SEEK_SET) ||
+seek( $IN, NUMBLOCKS * WORDSPERBLK * BYTESPERWORD, SEEK_SET )
-				die("Cannot seek: $!\n");
+  || die("Cannot seek: $!\n");
 
 foreach my $blocknum ( 0 .. NUMBLOCKS * 2 - 1 ) {
     printf( "Block %d (%06o)\n", $blocknum, $blocknum );
     foreach my $line ( 0 .. 7 ) {
 
         # Print out the words in octal
+        my @buf;
         foreach my $offset ( 0 .. 7 ) {
+
             # Get a word
             my $word = read_word($IN);
             exit(0) if ( $word == -1 );
-	    printf("%06o ", $word);
+            $buf[$offset] = $word;
+        }
+        foreach my $offset ( 0 .. 7 ) {
+            printf( "%06o ", $buf[$offset] );
+        }
+        print("  ");
+        foreach my $offset ( 0 .. 7 ) {
+            my $c1 = ( $buf[$offset] >> 9 ) & 0777;
+            $c1 = ( ( $c1 >= 32 ) && ( $c1 <= 126 ) ) ? chr($c1) : ' ';
+            my $c2 = $buf[$offset] & 0777;
+            $c2 = ( ( $c2 >= 32 ) && ( $c2 <= 126 ) ) ? chr($c2) : ' ';
+            print("$c1$c2");
         }
         print("\n");
     }