In order for a device to work on our network, it needs to do the following, which is kinda neat. The protocol is pure ASCII, so it's very readable to anybody watching the party line (RS-485). The master assigns addresses for communication, and auto-detects them. By default, a slave device must be inactive when first powered up. A slave will only accept commands after it has received a message "COPYRIGHT XXXX" where XXX is the company name and copyright date. A slave will not be spoken to unless it responds to a "COPYRIGHT" query with a valid response, which just happens to be the company name and a valid copyright date for that type device. Now tell me, are you going to make a device for somebody when it has to tell the world that its copyright belongs to your competitor in order for it to work? BTW, the guys wife who came up with this scheme is a patent attorney for a BIG bioengineering company. Andy Chris Eddy on 05/15/2000 06:42:23 AM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: [OT] When is a protocol proprietary? Gents; Your suggestions thus far have been very good pointers on the issue, much appreciated. To clarify, the task at hand is not to reverse engineer the software or even the hardware ( I would not feel comfortable reverse engineering one's software) but studying the message format on the communications link between the devices. It is a situation very analogous to the TV remote control debate. You can make a reciever, then study the message format, and make your own transmitter. But is this (A) legal, and (B) ethical? I have made the argument in the past that if one were to make a nockoff remote, and then market it, that if it were to exibit poor performance, then that product might make the manufacturer of the TV look bad, and that they had a compelling reason (but not a legal right??) to restrict third party devices that work on their TV. I obviously painted myself into a solid corner. Any further ideas? Such as case law on one manufacturer studying another's product? Thanks Chris Eddy