RocketModem Driver Source Package for Debian / Ubuntu

A couple of months ago I posted about using the current model Comtrol RocketModem IV with Debian / Ubuntu Linux. Ubuntu/Debian includes an older “rocket” module driver in-the-box, which works well for older RocketModem IV cards. But for the newest cards, it does not work at all. The current RocketModem IV is not recognized by the rocket module in-the-box in Linux, it requires an updated driver from Comtrol.

With some work (mostly outsourced to a Linux guru) I now present a source driver package for the 3.08 “beta” driver version (from the Comtrol FTP site):


Comtrol ships the driver source code under a GPL license, so unless I badly misunderstand, it’s totally OK for me to redistribute it here.

To install this, you follow the usual Debian driver-build-install process. The most obvious place to do so is on the hardware where you want to install it, but you can also use another machine the same distro version and Linux kernel version as your production hardware. Some of these commands must be run as root.

dpkg -i comtrol-source_3.08_all.deb
module-assistant build comtrol

This builds a .deb specific to the running kernel. When I ran it, the binary .deb landed here:


Copy to production hardware (if you are not already on it), then install:

dpkg -i /usr/src/comtrol-module-2.6.22-14-server_3.08+2.6.22-14.52_amd64.deb

and verify the module loads:

modprobe rocket

and finds the hardware:

ls /dev/ttyR*

To verify those devices really work (that they talk to the modems on your RocketModem card), Minicom is a convenient tool:

apt-get install minicom
minicom -s

Kernel Versions

Linux kernel module binaries are specific to the kernel version they are built for; this is an annoyance, but is not considered a bug (by Linus). Because of this, when you upgrade your kernel, you need to:

  • Uninstall the binary kernel module .deb you created above
  • Put in the new kernel
  • Build and install a new binary module package as above

Rebuilding the source .deb

Lastly, if you care to recreate the source .deb, you can do so by downloading the “source” for the source deb: comtrol-source_3.08.tar.gz then following a process roughly like so:

apt-get install module-assistant debhelper fakeroot
m-a prepare
tar xvf comtrol-source_3.08.tar.gz
cd comtrol-source
dpkg-buildpackage –rfakeroot

The comtrol subdirectory therein contains simply the content of Comtrol’s source driver download, and this is likely to work trivially with newer driver versions (3.09, etc.) when they appear.