Nord Drum 2 checksum

[sockmonkey]

Hi, I've been developing a patch editor/generator for the ND2, but am hung up on a system exclusive issue. Does anyone here know how the checksums are calculated for the Nord Drum 2? There's a 7-bit (1 byte) checksum for requests and a 21-bit (3 byte) checksum for voice data. I've tried a variety of CRC algorithms without hitting on the right one, maybe someone here knows the secret sauce.

Thanks, Jeremy

[Happy]

Wanted to do the same and asked Nord for this 2-3 years ago for the D2 and D1 to save patches more easily. Spend days on trying to figure it out but had to give up. Nord's answer then was that sysex/checksum "was not a secret but they just did not have it and CC could do the job". It is a kind if interesting as for older products (NL1/2/3) the Sysex was made available but then suddenly not anymore for any products. Around the same time Roland started to stop disclosing Sysex as well. Really like the D1 & D2, except for this. It is the main reason why I did not buy an NL4, A1 and an Electro and went for Dave Smith / Sequential products.

[pehaef]

Sadly it's a typical "forced obsolescence" strategy, the inane desire of marketing people to make sure we all buy only new products. What's extra sad is when they convince the engineers who no doubt know these details (because they wrote the checksum code for example) to also keep quite about them. One of these days I'll just have to open up the ND can and dump the EEPROM/Flash and disassemble the code myself. Many hours of extra work just because of those braindead marketing people. Depressing! And it's the main reason I don't ever buy new gear (unless it comes with full documentation, Linux support, and ideally source code).