The files in this archive provide a method for darkening the NeXT display
completely when logging out.  This prevents burn-in of the login dialogue
box.  This technique has been tested under NeXTStep 1.0 and 2.0.

To use the technique, follow these steps.

1. Pick a place to install the VidLev program and the LoginHook and
   LogoutHook shell scripts.  If you don't want to use /usr/local/etc,
   modify the BIN string in Makefile to identify the installation path.
   Make sure that the BIN path exists.
   
2. Become root and:

	# make install

   The install rule will compile VidLev, customize the LoginHook and
   LogoutHook shell scripts, install all three, and set root's defaults
   for the loginwindow program's login and logout hooks.

3. Reboot.  (This makes loginwindow aware of the login and logout hooks.)

When you log out the screen will darken completely.  You can rebrighten it
by pressing the "brightness up" key on the NeXT keyboard (next to the
"Power" key) -- moving the mouse or typing a login and password to the login
dialogue box will not restore brightness until after the loginwindow manager
has attempted to dim the login dialogue box (about 30 minutes after logoff).
VidLev will darken the screen again every 10 minutes until someone logs on,
so that loginwindow's post-logoff dimming won't accidentally raise the video
level from VidLev's complete darkness to a dim login dialogue box level.  At
login the LoginHook script sends a SIGHUP to the VidLev process and it
restores screen brightness values to ones remembered from logout time.

Vic Abell <abe@mace.cc.purdue.edu>
