Make sure you are running the latest versions of firmware for the Treo 650. I happen to have an unlocked edition so this is very easy to fix from PalmOne. I recommend going with the latest but this isnt a deal breaker. I am going to assume this from a total newbie position as yes, you can use pppd or wvdial from CLI. For our test we will be using Ubuntu 6.06 and Gnome-ppp. To enable “tethered” mode on the Treo you maybe lucky and dial #*83843733. I was unable with GSM and Cingular and instead used this software which works wonderfully. If anything they also officially support Linux. Sweet!

The hotsync USB cable will be all that is needed. I have problems in the past plugging into an external USB hub so keep that in mind.

Installing Software
I downloaded the USB Treo program and explored the zip file. I extracted the PRC to a SD-Card
and reinserted into the Treo. There was the program. I clicked enable USB modem and plugged the USB hotsync cable in. At this point I
apt-get install gnome-ppp
and waited for that to finish. Check dmesg for ttyACM0 to ensure that the kernel did pickup the hotplug device.

Gnome-PPP Settings
Before we can even start on that portion of the install lets enable a few LCP options we will need to ensure the connection stays put.

sudo vi /etc/ppp/options
Find in the conf file:
lcp-echo-failure 4
and change it to...
lcp-echo-failure 0
Next run Gnome-PPP from your applications menu. The settings most important here will be the username and password:

Also for the phone number put:
The final dialog box should look like this:

Lets digg into some of the options you may need to check to ensure this is transparent:

Init Strings needed:

Setup Dialog Box 1:

Setup Dialog Box 2:

After all is said and done. Click connect! You should see the gnome-ppp dock itself and lights start flashing. Something to keep in mind is that if your default route is pointing to eth0/wifi0 you will need to pull those interfaces down before the ppp0 can take over. Enjoy!