tried to add address only programming mode - but now can't drive my n gauge class 70 - OO intercity still working.
set address works!!  also now got a way to programme my new N gauge - branch tryingtofixngauge not needed - I'd accidentally (successfully!) programmed it to a new address
added (still untested) ability to use address only mode via UART comms.  so far this has only been tested from cold startup