--- 3m-810.pl	2008/09/28 18:19:37	6
+++ 3m-810.pl	2008/09/28 22:10:55	8
@@ -103,7 +103,7 @@
 
 			my @tags;
 			push @tags, substr($tags, $_ * 8, 8) foreach ( 0 .. $nr - 1 );
-			warn "## tags ",as_hex($tags), " [$tl] = ",dump( $tags );
+			warn "## tags ",as_hex($tags), " [$tl] = ",dump( $tags ) if $debug;
 			print "seen $nr tags: ", join(',', map { unpack('H16', $_) } @tags ) , "\n";
 		}
 ) }
@@ -161,9 +161,10 @@
 	foreach my $str ( @_ ) {
 		my $hex = unpack( 'H*', $str );
 		$hex =~ s/(..)/$1 /g if length( $str ) > 2;
+		$hex =~ s/\s+$//;
 		push @out, $hex;
 	}
-	return join('  ', @out);
+	return join(' | ', @out);
 }
 
 sub read_bytes {
@@ -218,6 +219,17 @@
 	}
 }
 
+# my $checksum = checksum( $bytes );
+# my $checksum = checksum( $bytes, $original_checksum );
+sub checksum {
+	my ( $bytes, $checksum ) = @_;
+	my $xor = 0;
+
+	if ( defined $checksum && $xor ne $checksum ) {
+		printf "checksum doesn't match: %04x != %04x data: %s\n", $xor, $checksum;
+	}
+}
+
 sub readchunk {
 	my ( $parser ) = @_;
 
@@ -228,21 +240,20 @@
 	my $length = read_bytes( 1, 'length' );
 	my $len = ord($length);
 	my $data = read_bytes( $len, 'data' );
-	my ( $cmd ) = unpack('C', $data );
 
 	my $payload  = substr( $data, 0, -2 );
 	my $payload_len = length($data);
 	warn "## payload too short $payload_len != $len\n" if $payload_len != $len;
+
 	my $checksum = substr( $data, -2, 2 );
-	# FIXME check checksum
+	checksum( $header . $length . $payload, $checksum );
 
-	print "<< ",as_hex( $header ), " [$len] ", as_hex( $payload ), "checksum: ", as_hex( $checksum ),"\n";
+	print "<< ",as_hex( $header ), " [$len] ", as_hex( $payload ), " | sum: ",as_hex($checksum),"\n";
 
 	$assert->{len}      = $len;
 	$assert->{payload}  = $payload;
-	$assert->{checksum} = $checksum;
 
-	$parser->( $len, $payload, $checksum ) if $parser && ref($parser) eq 'CODE';
+	$parser->( $len, $payload ) if $parser && ref($parser) eq 'CODE';
 
 	return $data;
 }