OK, yes, in theory, if you somehow managed to write your own programming software, and kept it to yourself, would anybody know? No. BUT, the minute you release it to the public, free or otherwise, you are infringing on Motorola's intellectual property.
Not necessarily. It's a very interesting question, in fact:
Could somebody legally write a freeware version of CPS that allows you to program Moto radios?
One of the "safe harbor" cases for reverse engineering (in the US) is that you're allows to reverse engineer something for the purpose of deducing its external interfaces and behavior, so that you can interface with it. The protocol used by CPS is exactly this sort of external interface.
So, I
suspect that if somebody wanted to take the time to reverse engineer the protocol between a Moto radio and CPS (using a serial port monitor or a USB bus analyzer), that would be allowable.
However, I also suspect that wouldn't be sufficient to allow you to actually program a radio. The code plug probably isn't sent over the wire in plain text -- rather, it's probably "encrypted" (that's in quotes, notice) in some way that the radio understands.
It's not at all clear to me whether the law (in the US) would allow you to reverse engineer the format in which the code plug is sent...
Like all things involved in software Intellectual Property law these days, it's an interesting question.
Peter
K1PGV
-- Not a lawyer, but a software engineer who deals with issues of software IP on an almost daily basis.