Thursday, 8 September 2011

Dedicated Wallpaper Screen - everyone should have one!

There are all sorts of reasons why a person might need cheering up. Luckily, there are also all sorts of ways to cheer yourself up. For example, there are books which make me laugh out loud no matter how down I'm feeling - which really does make the black cloud go away, at least for a while.

One which I can really recommend is to collect all of your favorite photos, and have a second screen on your desk which shows you a randomly changing selection of them. They don't have to be pictures that you've taken yourself, of course, but there's something especially cheering about seeing places you've been, cool things you've done, happy times you've had...

It occurred to me a while ago that you could easily hook up a screen like this, to a superannuated computer. Gee, you could even build a little desktop gadget with a screen and a microprocessor... then of course before I could do anything about it, Philips brought one out. They were rapidly followed by a bunch of no-name Chinese products with an extra twist - they contained a virus that infected your computer as soon as you connected them. Neat trick. I had an actual Philips one, which was malware-free but not explosion-free. One day I noticed that it was a funny shape, and when I took it apart the internal lithium-ion battery had exploded, with enough force to bend the solid metal frame. It has never been quite the same since, and anyway there's no longer room for it on my desk.

At the same time I bought the picture frame, I started assembling my favourite pictures - the same ones as in my Flickr account, with the addition of some family pictures that I don't particularly want to share with the world at large. I found a wallpaper changer that worked well for me, and whenever my computer was idle, they'd scroll by in front of me. It was great, but there's one problem: if I'm not actually using the machine, I'm probably not looking at it. And if I am using it, of course, the wallpaper is invisible under the clutter of a dozen windows.

Fast forward to my new Linux system. At the same time I bought it, I also bought a new monitor. There was nothing wrong with the old one, except a broken stand elegantly patched up with cable ties, but the new one has more pixels, and bigger is always better (n'est-ce pas?). So, I suddenly had a spare large format (1600 x 1200) monitor, and thanks to a superhuman feat of tidying, a space for it on my desk.

It took me a while to get round to making this all work, though. There are people who have had multi-monitor systems for years, but I've always preferred to have a single large one - hence the present 1920 x 1200 display.

It seemed obvious to me that I would need a second graphics card, so off I went to Fry's and bought a low-end one, a Realtek HD5450. I've got used to how well Linux deals with new hardware, so I just plugged it in and expected it to work. My optimism was misplaced, however. I'm running a recent version of Linux (11.04, Natty) and all the bits weren't in the right place, fixed with a bit of googling. No matter what I did, though, the system only used the built-in graphics on the motherboard.

A bit more googling showed me how to change the BIOS setup so it would use the new card - but then it would only use the new card. There was no way to get it to use both of them at once.

There was a seriously heart-stopping moment in the middle of all this. There was one BIOS setting that resulted in a psychedelic display as the system booted - a patchwork of constantly changing colors. Eventually the system came up normally - but how could I change the BIOS settings again? It seemed for a short while as if the only thing to do would be to buy a new motherboard! Luckily, unplugging the new card magically made everything work again.

In the end the solution was simple. You can run two monitors off the same graphics card, just plugging them into two different sockets. And I didn't even need the new card - thank you Fry's for an extremely liberal return policy.

It still wasn't completely over, though. Convincing Linux to run both displays wasn't at all obvious. Not only did I have to tell both Gnome (the desktop system) and the monitor drivers, but I had to do it in the right order - otherwise one undid the changes to the other. The X-windows configuration had to be changed manually, using the magic command "sudo dpkg-reconfigure xserver-xorg". Somehow this reads your mind, figures out what you're trying to do, then generates the corresponding xorg.conf file.

Finally I had it all working. Still not there, though. The "wallpaper" monitor is to the left on my desk. But Gnome wants to put everything on the left screen, unless you've explicitly moved it to the other one. There's a box you can click to make a different screen primary, but it only has a limited effect. Luckily, most X apps remember where you last put them, so it's just a question of "training" the apps you use most. Every now and then, though, I click on something, and can't understand why nothing has happened. Then I look at the wallpaper screen, and it's over there. So I call it, "here Fido", over it comes, and another app has got it figured. (Well, actually I drag it with the mouse).

And what a constant pleasure it is, to see all these pictures of things I've done and places I've been. While I've been typing this, I've had...
  • the tiny landing strip in the remotest part of Baja California, whwere we went whale spotting
  • a beautiful, moss-clad waterfall in the Oirase Gorge in northern Japan
  • a still-life composition of freshly caught fish in the market in Cap Breton, France
  • several shots of the Golden Gate Bridge, taken from different aircraft at different times, including the ones taken while flying under it in the heli
  • a visit to Potsdam, Germany in 1986, when it was still East Germany, with just a single smelly Trabant visible in the whole of a huge plaza
...and of course lots more. The screen in the picture at the top is showing a public footbath at Sakurajima in the very southern tip of Japan. What a visual feast!

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