> To change this, I tried a lot of different locale settings (and variant
> of these):
> 	LC_CTYPE=de
> 	LC_CTYPE=de.iso-8859-1
> 	LC_CTYPE=iso-8859-1
> 	MM_CHARSET=iso-8859-1

Looking at /usr/share/locale/de on a 1.5 system I don't see anything
that looks like LC_CTYPE information.  Unless someone knows otherwise,
in NetBSD-1.5 I don't think there is CTYPE information for the de
locale. :-(

In -current the situation may be better, with the incorporation of
work from the Citrus project:

http://mail-index.netbsd.org/netbsd-announce/2001/01/25/0000.html
http://citrus.bsdclub.org/index-en.html

> The next step would have been to read the libc source code, but 
> unfortunately, my disk is too small to untar it :-(

http://cvsweb.netbsd.org

> My system is a plain NetBSD-1.5 without any major modifications yet. Any
> help is greatly appreciated.

Someone who speaks German may be able to help you more than I can.

Regards,

Giles