Vitaliy wrote: >> Alternatively they use a prorietary 2-wire proctocol. Accidentally, that >> protocol is 100% compatible with I2C. > > I'm curious what the official rules for that are. So if I were to take an > existing protocol, add a couple of things, but keep my new protocol 100% > backwards compatible, would that be illegal in most jurisdictions? As Wouter says, it depends :) If, for example, the protocol or parts of it are protected by patents, it would be illegal in most if not all jurisdictions where these patents are valid. For a patented technology, it doesn't matter how you found out about it: clean room approach or straight copy, it's all covered by the patent. I think Bosch has patents on the CAN protocol. If the protocol's name is protected by trademark, you may be able to do legally what you said. You wouldn't be able to say that it is "(tm)", but probably that it is "(tm) compatible". Gerhard -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist