To me, a non-expert in the inner workings of Linux, it's almost as though the powers that be (if they exist) don't want you to know anything about how non-graphic stuff works, which makes it hard to fix something when it goes wrong. I did find that a useful place to experiment is in the file /etc/console-tools/config, where I ended up putting these lines:
# Turn on numlock by default
###NOTE: Changing all below from "lat2-16 to lat1-16" trying to fix wrong chars. on consoles --jrr 6-25-06
### Changing to lat0-16 on 6-26 in hopes of further improvement--jrr
### Changing to lat9u-16 'cause I saw that's what Damn Small Linux uses, and tried it and got better results
The last one is the one that worked best for me, and restored the proper boxes and other "graphic" characters to the MC display in consoles. However, it probably isn't the best one for a Hungarian user.
The config file referred to is unusually well written and tells what to avoid as well as what you can do.
One problem with all this, to judge from scores of posts and other material I read through Google searches, is that the Unicode standard is not understood by lots of software. So characters don't get reproduced right. In an ideal world, everybody could just use a Unicode character set and see his/her native alphabet's characters correctly everywhere, but the world isn't ideal yet.
The locale issue is one I simply don't understand after reading probably hundreds of pages about it. I just found that for me the best compromise setting is "LC_ALL=C" with my own language setting set to "en_US" which is not surprising since I live in the US. Even then, programs complain that "en_US" is not understood by the "operating system," which is plainly false, since it works.
I certainly understand why people stay with Windows.
I left all the useless lines in in order to see what I had tried with not-so-good results. They are just a small part of what I experimented with, though.
And by the way, thanks for helping me reach 1,000 posts today! I must celebrate, probably by buying an MP3 player that won't work with Linux without weeks of fiddling ...