[jasomill]

While I have no personal experience with the 3B2 series, its documentation[1] clearly illustrates the GP's complaint: starting from the most significant binary digit, bit numbers decrease while byte addresses increase.

As for networking, Ethernet is particularly fun: least significant bit first, most significant byte first for multi-byte fields, with a 32-bit CRC calculated for a frame of length k by treating bit n of the frame as the coefficient of the (k - 1 - n)th order term of a (k - 1)th order polynomial, and sending the coefficients of the resulting 31st order polynomial highest-order coefficient first.

[1] https://vtda.org/docs/computing/AT&T/3B2/3b2_Assembly_Lang_P...

[zephen]

I know this particular pain intimately.

I was in charge of the firmware for a modem. I had written the V.42 error correction, and we contracted out the addition of the MNP correction protocol. They used the same CRC.

The Indian (only important because of their cultural emphasis on book learning) subcontractor found my CRC function, decided it didn't quite look like the academic version they were expecting, and added code to swap it around and use it for MNP, thus making it wrong.

When I pointed out it was wrong, they claimed they had tested it. By having one of our modems talk to another one of our modems. Sheesh.