> When I try to start it (blackbox), I get:
> "BaseDisplay::BaseDisplay: connection to X server failed."

 How did you start blackbox? Using .xinitrc? Using a shell when X was
already started? You started X as a normal user and then started blackbox
as root?

> I tried looking for .xinitrc and there is none on my system. I don't really know what to do
> next to have blackbox working.

 Well, .xsession does the same. The global XSession file in
/usr/X11R6/lib/X11/Xdm is ben used when starting xdm. You can copy it to
~/.xsession or .xinitrc, edit it and just leave the last section to start
your own commands and replace twm by blackbox.

 It is a good idea to start Xdm, btw., on boot time.

Markus Illenseer