Before I tried working with the defaultdir command, I noticed that
the terminal log file states, as its first entry,
LOG: DOSBox-X's working directory: /Users/billt
even though it was invoked from
/Users/billt/dellxps17
However, copying the map file there didn't help. I don't have to
REMAP. The Mapper Editor now knows that Left-Command is assigned to
Mod1. However, this still doesn't actually work in the program.
I also still don't seem to be able to tell the program to use 42 (or
43) lines, and to use TTF. So I invoked these from the menu at each startup.