[arch-general] gdm not found when booting into runlevel 5

[Nigel Henry]

I already have one instance of Archlinux installed that has xorg, and KDE 
installed, and from looking at /var/cache/pacman/pkg, I also have gdm 
installed. Now this instance of Archlinux works fine, and I can login to KDE 
with no problems. The graphics driver is trident, and according 
to /etc/X11/xorg.conf, that is the one that is being used.

I now have installed another instance of Archlinux (Don't Panic) on a new 
machine that I've built. Mobo is Asus M2N-X Plus, and has no onboard graphics 
card, so I installed one with an ati chipset .

Booting into Archlinux is ok, and I did a pacman -S xorg, and after that, a 
startx started the xserver with no problems, apart from the usual crappy 
display.

I then did a pacman -S kde, and a whole bunch of kde stuff was installed, but 
a reboot, and changing to runlevel 5 just brought me back to the text 
(runlevel3) login.

Looking at my earlier install of Don't Panic, I see that I'd also installed 
the gdm package, so I installed it on my new install of Don't Panic. Doing a 
reboot after this, there is no change, and booting up, and appending the 
kernel line to 5 has no effect, and I still find myself in runlevel 3.

Is there some file that I need to edit, in order to use gdm as the display 
manager?

Nigel.