I'm trying to troubleshoot my XFree86 config on a Redhat 8 box, trying my best to achieve 1024x768 @ 85Hz on an Intel i810 integrated chipset.

What I'd like to do is shutdown X, make a change to the XF86Config file in a text shell, then start X back up. Unfortunately I'm a newbie and don't know the tricks, and the basic Ctrl-Alt-Backback keystroke simply restarts X rather than shutting it down. I need a true shutdown of X since my video problems are distorting the screen...I need the video card to revert back into whatever mode it uses during run level 3.

The fanciest thing I've tried is getting the PID of the X process and killing it, but that resulted in a system lockup. Just need the command which shuts down X gracefully.

Thanks all.

try just opening a terminal, and issuing telinit 3 or init 3 and see if that works....i find it odd that ctrl-alt-backspace restarts X, and if worse comes to worse, and none of the above works, then you can always just open your /etc/inittab file in a text editor and change the line that says :
id:5:initdefault:
to read
id:3:initdefault:
and then reboot and it will automatically bring you to console upon boot....and of course, after your done doing what your doing, you can edit this back to 5 if you wish..

try using telinit 3
This will switch you to runlevel 3 for your testing. Then you can use telinit 5 to go back to X
HTH

--doh ya beat me to it