Hi again,
I have the osm map on the Garmin, thanks for all the help. I now have the Forth and Tay gpx file.
So on the microSD card I have the following structure:
/GARMIN containing a directory ./GPX/ and the gmapsupp.img map file image
/GARMIN/GPX/routename.gpx file
So I have learned:
to start the route off:
select 'Where To?' icon.
select 'Tracks' icon
lists:
'Current Track'
'Forth and Tay'
click the track you want and you are taken to the map page with a large GO button on the foot of the screen.