Jack,
I found that with the 540 in Garmin/Garmin i/o mode I could indeed
upload a set of way points from a route generated by my old Navmaster
III program without invoking an additional SD chip but although this set
was uploaded as a route named "crabbing" only the way points appeared on
the 540 chart not the joining lines. I was of course able to join them
using Route Edit. Using the Garmin 45xl there is no graphic
representation of a route only a sequence of way points that you follow
from point to point as you travel however the distance and time en route
to the next way point and to the remaining (untraveled) way points is
displayed.
It is a pity that Garmin don't reveal the detailed differences and
similarities of the data transfer of their products.
Regards, Dick