C-Man.
Still pretty much the same with this configuration. I can send 1,2,3 and receive them correctly, but 4 upwards is not received or wrong. I am pretty sure that the receiving end is ok, difficult to check what is being sent out as they are non printable characters. Also difficult to do a simulation without a major change to s/w, as I have probs with peripherals and eeprom.
Stange thing though, if I try to use printf or putchar insted of SBUF, the prog does not return from the function, thus effectivly locking the mpu. I would sumise that these funcions are waiting for a flag to be changed, and this it is not happening.
I think I will have to re-write a small section of code that I can simulate, and then go on from there.
I really appreciate all your advice, thank you so much.