Briand1

I'm new to this forum, hence the rather late reply. I have spent a while decoding all the lines in a dlm file and written the results up in a short word doc. Most of what has been said here is correct - all the checksums are sequential bit-wise exclusive ORs (XOR). The reason that the checksum line that shows the file checksum as #boards +1 if the number is even and #boards -1 if it's odd is only true if the low board number is 1. As follows: 1 XOR 32 becomes 000001 XOR 100000 = 100001 i.e. 32 1 XOR 31 becomes 000001 XOR 011111 = 011110 i.e. 30 However if you play board 10 to 32 10 XOR 32 becomes 001010 XOR 100000 = 101010 i.e. 42 Actually, even this is only part of the story because 2 other factors, the dealing method and next board to be dealt are also included in the checksum. If you're still interested I'd be very happy to send the .doc with all the details explained. Brian