Fighting RSI (Part 1)

I’ve lately started to feel RSI related pain thus felt the need to make some changes to my working environment. There’s two steps: Buy a proper keyboard and buy a trackball. Since the mouse seems to be the biggest pain inflictor, I decided to begin with buying a proper trackball.

I’m actually not the mouse overusing type; I use the keyboard extensively and am annoyed most of the time I have to grab for the mouse. On the other hand – some of my regular activities involve a mouse with a degree of precision, so I cannot go keyboard only or use slow or imprecise pointing devices.

I’ve used trackballs before and I always liked them, but I developed a habit of purchasing really cheap mice and keyboards in the past couple of years. I’ve used A4 Tech trackballs in my early days, but they don’t seem to make them anymore. I’ve also used a Logitech Marble Mouse a while ago (until the cat decided to see what the cable tastes like) and I’ve really enjoyed using it. Nonetheless, I wanted to see all the options and find the ideal one for me.

There are two notable manufacturers of trackballs nowadays: Logitech and Kensington. I’ve looked at the portfolios of both companies and had to exclude most of Logitech’s products since I want an ambidextrous one (I’m left handed and although I’ve always used mice right handed, I want to keep the opportunity of switching when I feel like it). Most of Kensington’s models are ambidextrous, but I excluded the more expensive ones. I might try one of these later but I don’t want to invest a lot of money right now, considering the prices of ergonomic keyboards. I also excluded all mice lacking a scrolling mechanism. In the end, I ended up comparing two trackballs:

Kensington Orbit with Scroll Ring

Logitech Trackman Marble (used to be called Marble Mouse)

I got both (they’re available for about €30) and evaluated each for a while.

What I did to evaluate them:

Setting it up

I tend to use several different computers and operating systems and what I don’t want is having to configure each one extensively for my mouse – or in the worst case even install special drivers. I’m using Linux most of the time but am also frequently forced to use Windows XP so it has to work properly for both of these.

Playing Doom 3

I like to play computer games, and mouse control is important for most nowadays, especially Shooters, which is why I picked this one for evaluation. I know, it’s a bit outdated, but I still didn’t finish it, so it was available.

Using the Gimp and Blender

I’m not a graphics designer, but I still like to do a simple sprite here and a simple mesh there, especially when hacking on games.

Kensington Orbit with Scroll Ring

Since I knew the Logitech already, I started with the Kensington. I just love the looks. The best thing about this one: It’s got a highly usable scroll ring around the ball. It’s very comfortable and feels similar to using a regular mouse wheel – with the difference that you can give this one a good spin to scroll real fast. It also comes with an attacheable wrist rest, but I didn’t find it that comfortable and purchased a gel pad instead – works pretty well since the device is quite short without the wrist rest.

Its size and form is great for my (pretty much average) hand size and my wife (who has considerably smaller hands) finds it comfortable as well. You are basically laying your hand on top of it – I took a while until I got used to this and found a non-straining position.

The problem with this model is the missing third mouse button. If you need the third mouse button (as I do), you’ll have to use three button emulation. This works by pressing the left and the right button together.

Setting it up

Absolutely straightforward on Linux: Just plug it in and everything works. Three button emulation is automatically activated for mice with only two buttons.

On Windows, it works out of the box as well, but it’s rather complicated to get three mouse button emulation to work. It was eventually possible using the tool AutoHotKey and this script. Putting that and the following line in an AutoHotKey script worked for me:

MakeChord("LButton", "RButton", "MButton", 30)

I’ve uploaded a compiled version of the script; just grab and execute it to enable three mouse button emulation. Put it in your Startup directory and it’ll become active whenever you start Windows.

Playing Doom 3

It worked surprisingly well. The precision is certainly good enough, I can turn fast enough, the buttons are very responsive and the scroll wheel works like a charm for scrolling through weapons (although I almost never use that).

I was worried about the third mouse button evaluation but it turned out to be a minor problem. In Doom 3, the middle mouse button is used for zooming, and if you want to shoot while zooming, you are required to press the left and the middle mouse button at the same time.

This does work with three button emulation: Hit both buttons to zoom in, let go of the left one and its still zoomed in and the freed button can be used to shoot. You can do the same thing with freeing the right mouse button, so you can switch between flash light and a proper weapon while zooming in. I’ve noticed that its virtually impossible to both shoot and switch between flash light and weapon while zooming in with only the mouse, but I really don’t care. There’s always the keyboard (in this case the Y key) and I can’t think of a game actually requiring a third mouse button anyways, so I’m not worried at all.

Using the Gimp and Blender

Works quite well, as for the game. Great precision and a sensible scroll wheel. The third mouse button is used extensively in Blender and although it worked great so far, three button emulation got me annoyed in minutes and I started to fail to hit the keys. I hope it’s possible to get used to this, otherwise I’ll have to use a keyboard shortcut for this.

Logitech Trackman Marble

The next day was devoted to the Logitech. This model is extremely popular (for a trackball). The ball is exactly the same size as the Kensington’s and the form is pretty similar too, but instead of lying your hand on top of it, you’re putting it around it – very similar to how you’d hold a regular mouse.

It’s got four mouse buttons and you can use them however you like. There is no real scrolling mechanism, but you can use the two additional buttons for that. I can think of two possible variants:

  • Use third button emulation and use the third and fourth button as scroll up / scroll down.
  • Use the third button as the third button and use the fourth button for scroll wheel emulation: You hold it down and move the trackball to scroll. This way enables you to scroll both vertically and horizontally.

I went with the second variant since I find it awkward to scroll using button presses and it’s simply an inferior variant of the Kensington that way. The second way has actual benefits.

Setting it up

It is not straightforward on Linux, but since the device is quite popular, there are guides like this one.

The proper (hal) way didn’t work for me so I had to use xinput. I was able to make everything work as I wanted it by putting the following in a file called /etc/xprofile:

/usr/bin/xinput set-button-map '"Logitech USB Trackball"' 1 8 3 4 5 6 7 2 9
/usr/bin/xinput set-int-prop '"Logitech USB Trackball"' "Evdev Wheel Emulation" 8 1
/usr/bin/xinput set-int-prop '"Logitech USB Trackball"' "Evdev Wheel Emulation Button" 8 9
/usr/bin/xinput set-int-prop '"Logitech USB Trackball"' "Evdev Wheel Emulation Axes" 8 6 7 4 5
/usr/bin/xinput set-int-prop '"Logitech USB Trackball"' "Evdev Wheel Emulation X Axis" 8 6

On Windows XP, you’ll have to install the Logitech SetPoint driver. Since the default configuration is not the one I wanted, I used the software to assign the small button on the left to the middle mouse button.

Playing Doom 3

This didn’t work as well as with the Kensington. This one moves slower so you have to give it a good spin to turn the player completely around, but if it would really get annoying, one can adjust the sensitivity.

Although it moves slower, precision and speed are still acceptable and even the mouse wheel works in an almost sensible way, although it doesn’t seem to work at all in Windows; whatever the driver does, it does not send real scroll events.

You can in any case not use it to switch weapons while turning because the mouse wheel blocks normal mouse movement. But as with the third mouse button of the Kensington: There’s always the keyboard and I never use the mouse wheel to switch weapons anyways.

I played the same sequence as with the Kensington (the one where the Revenants first appear) and I feel I was a bit better with the Kensington.

Using the Gimp and Blender

The precision is adequate and the horizontal as well as vertical scrolling is ideal for the Gimp (at least I spent a lot of my Gimp time with zooming in and moving the zoomed area with the scroll bars). I would wish for a little more scrolling precision though, it does still feel like the discrete steps movement of a scroll wheel so it gets quite useless when precise movement is required. Horizontal scrolling is not used at all in Blender’s default configuration, but the real third mouse button was a relief when using Blender.


All in all, the trackballs are quite similar:

  • They both use optical technology, with the Kensington moving faster, which is – as far as I know – proof of a higher precision.
  • The balls are of the same size: You can actually put the one from the Logitech into the Kensington. Doesn’t work the other way around though, the Logitech probably relies on those black dots on the ball.
  • They are both ambidextrous and comfortable.
  • The set up is a bit complicated for both of them. The Logitech is difficult to configure on Linux while the three button emulation for the Kensington was difficult to set up on Windows. In any case, since I use both systems, there is no winner here.

The real difference is the number of buttons and the scrolling mechanism. The way I set the Logitech up, ithas a real middle mouse button and another scroll axis (although the Logitech’s scrolling is in any case only a hack, just like third button emulation with the Kensington). The Kensington has humble two buttons but a very decent scroll ring.

Eventually, I went for the Kensington. My reasons:

  • I need a scroll wheel more often than a third mouse button.
  • The small buttons of the Logitech force my hand into a rather awkward position, since I press them with my finger tips.
  • The Kensington seems to have a higher precision.
  • The Kensington looks a wee bit better in my opinion.

But don’t get me wrong, it was a difficult decision and both devices are great.

In the future, I might decide to get the more expensive Kensington Expert Mouse:

Now I’m setting sails for buying a proper keyboard, I will describe my findings in part 2.