I have seen a number of programming cable schematics on the internet, but I couldn't understand very much how they worked. From what I picked from all schematics, it appears the protocol uses the CL_DATA pin for both RX and TX, and the CL_SW pin to signal stuff.
However, I couldn't really understand the protocol that the radio uses. Can someone please explain? What are both the radio and the computer interfaces sending and expecting in each pin?