Best bet is to get the 1:50 ,000 from other sources , and use Oziexplorer, I have used Ozi for a long time now and the program is excellent. It will take different map software on CD . Or you can scan topo's and geo referance them.
I like the Oziexplorer program for building maps of select areas using the manual track function. That way you can have contour data , roads , trails whatever , right on your Garmin 12, and other gps screens. Been doing that for 10 years now. Pretty slick, but I prefer geo ref. maps over scanned ones, less time and trouble. Although scanning areal photos, can also be geo referenced.
And lets not forget Google Earth, if in a darkened area the resolution is good and data is right at the bottom of the screen. Oh has anyone picked up the 20 dollar gps option for google?
Frank
Molan Labe