My GeForce 4 is able to support two monitors. I have had no problems with both under Windows, but only one will display when I start X. To get both of them to work, what do I need to change? Do I just have to add another monitor in my /etc/X11/XFree86 file?

Ive fought with this every install of LInux since i got my Linux bug.

This is what I did. no guarentee it will work for you. Read every Readme you can find before running any of these steps.

Log in as root

Go to NVIDIA.com

Choose D/L drivers

Choose Linux and FreeBSD Drivers

Choose the latest IA32 drivers

follow the instructions to install drivers
utilizing the NVIDIA Linux Update

While there print out the readme - text version

pay special attention to Appendix I (configuring twinview)

when the installation tells you to edit your XF86Config-4 file goto file:/etc/X11 and open XF86Config-4 with KWrite.

In the Section "Device"

change Driver "nv" to Driver "nvidia"

Add the needed Twinview options from Appendix I

I added these options:

Option "TwinView"
Option "TwinViewOrientation" "RightOf"
Option "SecondMonitorHorizSync" "30-69.0"
Option "SecondMonitorVertRefresh" "50-120"
Option "MetaModes" "1280x1024 ,1280x1024;"
Option "ConnectedMonitor" "CRT, CRT"

if you use these options

YOU WILL NEED TO

a. replace my SecondMonitorHorizSync range with the proper range of your second monitor

b. replace my SecondMonitorVertSync range with the proper range of your second monitor

you may possibly need to:

c: replace my MetaModes with the resolution you want monitor 1 and 2 to run at.

d: replace my TwinViewOrientation with your orientation. Values in Appendix I

Hope this helps

G.i.P

Here is a sample for dual monitor as well. Just pay attention to mainly screen, card and monitor sections, just to get an idea.

GiP, you had exactly what I was looking for.
Thanks for both of your all's help.