Finally someone found me some manuals for the YAMAHA robot. A quick scan however did not reveal the presence of a 'Compile' instruction. Since I do not have the programming terminal, which should be part of the system, the only way I could make the thing move was to issue direct commands, which are interpreted and executed. Not the most ideal way to create a sequence... Maybe it is not possible at all to emulate the Programming Terminal through the serial Host Port. At leas I have a good description of the syntax of the commands which are accepted. I have thought of building a dedicated terminal which can be hooked up on the programming port, but then I still need to know the codes for Edit, Compile etc.. I guess it'll take some time before I have a working G-code driven CNC milling robot :-(
As a last resort I can always disassemble the firmware, but of course I am not looking forward to such an exercise!