how to allow downloading a .map file

Apologies if this is RTFM stupid....

I have a site for a popular strategy game (Dominions 2) which wants to be
able to offer the games map files as nightly randomly-generated variations.
The .tga images are ok but for some of the popular .tga he wants to simply
generate the text .map files so people can click on them and get the
download popup.

Unfortunately Apache (debian linux in case it matters) is treating them as
html map files. Is there a way by .htaccess or http.conf to set a
particular directory as treating .map files as .txt files?

Gandalf Parker
--
I know its called the World Wide Web
and I can see just why.
Today I built my piece of web,
Im spider now, not fly!
- Gandalf Parker