Reviving my old Logitech TrackMan Marble FX

I am probably different than most users, but I am a a fan of unusual input devices. I prefer Laptops with trackpoints - I immediately disabled the touchpads on my Lenovo laptops (a T61 and T42) in the BIOS when I received them. My first Laptop (a Toshiba Portege 3440CT) didn't even have a touchpad to begin with. It's a pity that trackpoints seem to a dying breed.

And I don't like using regular mice on my desktop, either! Actually, my most favourite input device is a trackball - I purchased a Logitech TrackMan Marble FX a long time ago, and used it for years. Then computers stopped having serial or PS/2 connectors, and I replaced the trackball with an USB mouse. I never really got the hang of using mice, but Logitech (or other vendors) somehow never came up with a suitable replacement model for the Marble FX with a USB port. I recently looked at the Logitech Trackman Optical, but was not convinced by the reviews I read, and the fact that it requires batteries (a trackball is a stationary device, so a cable does not really interfere here!). The Microsoft Trackball Explorer might have been an option, but it seems to be impossible to get nowadays.

After experimenting with several mouse models (Cherry, Microsoft), I decided to revive the TrackMan Marble again. It comes with a PS/2-connector by default, so I first tried to connect it to my PC using a PS/2-to-USB converter dongle. This actually worked without any tweaking, but had two limitations: the fourth mouse button was not detected anymore (I could have lived with that) and the Trackball stopped responding after it had been idle for a while, requiring me to restart the X server to get it working again.

So using the PS/2-to-USB dongle was ruled out and I tried an Serial-to-USB dongle instead:

lenz@thebe:~> lsusb|grep Serial
Bus 002 Device 006: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port

When plugged in, udev creates a new serial device /dev/ttyUSB0 which I needed to inform the X server about. Fortunately it's possible to define multiple input devices in the xorg.conf configuration file. Using the serial port actually had another advantage - I was able to add some trackball-specific tweaks that would have collided with the settings of the "regular" PS/2 mouse section that I needed for the builtin trackpoint of my Thinkpad. It required some tweaking and testing, but this is what I added to xorg.conf to be able to use the TrackMan Marble FX in addition to the builtin pointing device:

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    InputDevice    "Trackball" "SendCoreEvents"
    Option         "Clone" "off"
    Option         "Xinerama" "off"
EndSection

Section "InputDevice"
    Driver       "mouse"
    Identifier   "Trackball"
    Option       "Device" "/dev/ttyUSB0"
    Option       "Name" "TrackMan Marble FX"
    Option       "Protocol" "Intellimouse"
    Option       "Vendor" "Logitech"
    Option       "AngleOffset" "10"
    Option       "Buttons" "8"
    Option       "Emulate3Buttons" "off"
    Option       "EmulateWheel" "true"
    Option       "EmulateWheelButton" "8"
    Option       "YAxisMapping" "4 5"
    Option       "EmulateWheelInertia" "8"
EndSection

You may wonder about the 8 mouse buttons, as the device only has four physical buttons. Interestingly, the fourth button on the TrackMan reported itself as "button 8" when I probed it with "xev", so I needed to make sure the server is aware of it. When pressed, the trackball now acts like a mouse wheel and allows me to quickly scroll across long documents - very handy! Now I just hope that the button switches in the TrackMan last for another while - until some vendor eventually comes up with a suitable replacement...