On 07/24/2016 06:41 AM, Tony Whyman wrote:
On 24/07/16 00:18, wkitt...@windstream.net wrote:
i've already checked the polynomial ($edb88320) is the same in both, the
original implementation (converted to TP4 in 1988) and this implementation...
Are you sure that you are dealing with a CRC algorithm? ISO 8073 TP4 uses an
arithmetic checksum (Fletcher).
ahhh... TP4 in this case is Turbo Pascal v4... i've had a lot of code for a very
long time... especially code that was posted to the PASCAL and PASCAL_LESSONS
echos on Fidonet ;)
If you are using genuine CRC32 then
http://www.tty1.net/pycrc/
is a good reference for all the different variations. It will generate 'C' code
for you but still a good baseline reference. I've used it successfully for CRC
implementations (some quite oddball in the aviation sector).
thanks for the info! if you've read my other posts by now, you'll see that the
function in FPC's crc unit does some things automatically that blow our desired
operation out of the water... we have to initialize the crc variable ourselves,
feed each character individually to the crc routine and then leave off the
finalization which flips all the bits over... it comes down to needing the
result in LSB to MSB format like was used with analogue UARTS which feed the
values to the serial port in reverse...
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