Hi Larry,

"...I don't think a TDF will work, though [for showing user_loc.txt
positions on geographic charts]..."

Unfortunately, you're right; it won't work. For that, I'd have had
to ensure that 'user_loc.txt' stored each location in a single line,
instead of spreading the data across five lines per location. Best
I can suggest, in the meantime, is to use something resembling Jari's
impact TDF... though as you mention, this would mean updating both
user_loc.txt _and_ a separate file with similar information.

-- Bill