[zzo38computer]

It would still be possible to be open source, even if it cannot be altered, such as by storing it in ROM (or storing a checksum so that only the exact version will run; this works better if the program is written in assembly language, since then you do not have to worry about the compiler messing up stuff). It could also be designed allow the code to be uploaded but to disallow transmission in that case, making it so that if the code is altered then it can only receive, and cannot transmit. Another alternative might be that the radio and the DSP are separate components in a single package, and then if you want to use them separately you will have to break the package to reveal the parts, and then it cannot be resealed; you will have to make your own and lose the warranty. (This last alternative is what I think is good, but if that won't work (I don't know much about its working, so maybe it won't work) then the others ways might do.)