you run the unit and generate the bif when it errors saying the map is not activated

then you activate the map using one of the tools (I use bbstools)

so the bif is generated at first boot of the tomtom, and the bif file contains the serial device code

the me ta file activates the map

once all the above are done , tt7.910 is active using the bif, and the map is activated with the bbs tools
when both are active, its job done