Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Building a Video Wall out of Old Laptops?

Cliff posted more than 7 years ago | from the that's-one-use-for-'em dept.

Displays 52

alphakappa asks: "I am interested in building a video wall as a personal project using recycled old laptops so that I can make use of the display controllers that are already present. Is there free or cheap software that can extend the display on Windows and still be capable of showing different videos on different zones (like, say run a video in one zone while showing a powerpoint presentation in another one) What tools would you use?"

Sorry! There are no comments related to the filter you selected.

It will look like crap in any case (4, Insightful)

Gothmolly (148874) | more than 7 years ago | (#18728863)

Each old recycled laptop will have a different color scheme, brightness and viewing angle. DSTN vs. TFT, relative strength or weakness of the backlight, etc.

yes, yes, I am a troll for mentioning all this, blah blah blah

Re:It will look like crap in any case (1)

fbartho (840012) | more than 7 years ago | (#18728935)

Less likely if you happen to have a source of homogenous laptops that all reached end of life at the same time...

Re:It will look like crap in any case (1)

NerveGas (168686) | more than 7 years ago | (#18731605)

If you have access to a hardware calibrator, good things can be done. They might not match exactly, but they can often be made to match enough to surprise most folks. You do have to pick a sort of "lowest common denominator" for brightness, though.


Easy. (0)

Anonymous Coward | more than 7 years ago | (#18728885)

Buy a wall of macbook pro 17's. say, 96 machines.

load the movie into quicktime on all 96 machines.

press 'play' on the IR remote.


wait, wat was the question? oh yeah, silly.

Projector (5, Informative)

Dan East (318230) | more than 7 years ago | (#18728919)

Buy a projector for $1000 and be done with it. The display controller is part of the motherboard, so you would need the entire laptop, not just the display. Thus the power consumption would quickly increase since you're powering entire laptops. Also, the lead length between the panel and the onboard controller must be very short - just a couple inches. So the bulk of the laptop will have to be mounted right with the panel. The displays will look significantly different - particularly with respect to white (some will have a yellow tint, others a blue tint), If you sit down and add up the bandwidth - full motion video at say 1024x768, times however many laptops you're driving, equals a crapload of bandwidth. We're talking gigabit requirements. If these are old salvaged laptops then you'll be lucky if they even have 100Base-T.

As I said, buy a projector for $600, plug it in and enjoy.

Dan East


Anonymous Coward | more than 7 years ago | (#18728939)

If you don't know what Cmd-Shift-1 and Cmd-Shift-2 are for, GTFO.
If you think Firefox is a decent Mac application, GTFO.
If you're still looking for the "maximize" button, GTFO.
If the name "Clarus" means nothing to you, GTFO.

Bandwagon jumpers are not welcome among real Mac users [] . Keep your filthy PC fingers to yourself.

You've already lost, rebel scum. (-1, Troll)

Anonymous Coward | more than 7 years ago | (#18729461)

Cmd-Shift-Control-4, Spacebar is superior to either of those anyway.

If you don't know what ps aux is for, GTFO.
If you think Camino or Safari are decent Mac applications, GTFO (hint: anything WebKit-based blows goats).
If you haven't mastered Quicksilver, GTFO.
If you don't know why Apple needs to FTFF, GTFO.

Real Mac OS X users know all of these things and greasy emo kids like yourself couldn't grep their way out of a paper bag.



dan_bethe (134253) | more than 7 years ago | (#18733697)

If you think the "open apple" key is called "command"; if you think ADB was made for Macs; if you think the Mac prototype could bootstrap itself; if you think a Mac's floppy drive is a unique design; if you think the Mac was the first easy-to-use personal computer; if you don't think monochrome can be green; if the names Burrell, Atkinson, and Raskin mean nothing to you, then .... whatever.

Apple // forever!!!

The Projector bulbs (3, Informative)

dj245 (732906) | more than 7 years ago | (#18729315)

The major cost of projectors is in the bulbs. A $600 projector that takes $300 bulbs that only last maybe 2000 hours is no fun. When you have the $300 bulb on your mind you get really stingy about turning the TV off all the time. To get around this, there are about two solutions.

1. Build you own projector, and spec a better cheaper bulb that lasts longer
2. Buy something like the LumenLab Evo [] which takes $30 bulbs that are supposed to last 6000 hours.

I went with option 2 because I'm a lazy bastard. While there are better projectors with higher resolution, for now (I graduate in 3 weeks) it was worth every penny and then some.

Re:The Projector bulbs (0)

Anonymous Coward | more than 7 years ago | (#18732113)

How's the color reproduction on that projector? With an HID bulb I'd worry about everything looking too bluish.

Does the projector correct for it in software/hardware?

Re:The Projector bulbs (1)

dj245 (732906) | more than 7 years ago | (#18732705)

It seems good to me, but I could probably look at something with no red and see nothing wrong with it. It has adjustments for blue red green brightness contrast etc. It also has a handful of profiles you can toggle that have presets for color and brightness correction. One of these profiles is a user-defined profile. This is great for switching between inputs which may have radically different signals.

All of this is for the 1.0. The 1.1 might not have this (they seem to have cut a lot of features)

Re:The Projector bulbs (1)

karnal (22275) | more than 7 years ago | (#18732185)

I have a quick Q for you- how quiet is this puppy? ( the evo v1.1) - I'd be concerned with the thing being a little loud to offset the heat of the bulb. While we're on this subject too, how much power is consumed by this projector? This would directly relate to heat given off, which would probably be more than a few lcd panels...

Also, since the res is 16:9 - and low at that, I wouldn't have a use for it in a panel display setting. Maybe for something like a conference room or showing movies, but with the poster's requirement like, say run a video in one zone while showing a powerpoint presentation in another one) I would guess that a higher resolution would be required for multiple displayed items at one time.

Any further thoughts?

Re:The Projector bulbs (1)

dj245 (732906) | more than 7 years ago | (#18732641)

I have the 1.0. Its a bit on the noisy side. I I haven't gotten around to replacing the stock 40mm fans with something better yet. The 1.0 uses around 170W on my Kill-A-watt meter, which really isn't that much when you compare to the 100W that my mothers 35" tube TV uses.

The 1.0 isn't 16:9. Its 15:9 or 16:10 or something weird like that. I always use 4:3 mode anyway. Its good enough for movies, and its the best TV I ever had. I have a hard time looking at smaller TV's now, even when they are generally considered "big" (32").

Re:Projector (2, Interesting)

prefect42 (141309) | more than 7 years ago | (#18729773)

If you're merely looking to upscale, the bandwidth isn't a killer. Multicast/Broadcast the video and play it back with vlc, and it'll do the tiling for you. You just need a bunch of machines running vlc.

Practicality (3, Informative)

cephalien (529516) | more than 7 years ago | (#18728925)

This really doesn't seem feasible, unless you have some serious hardware engineering prowess. What it seems like you want to do is span the laptop video on multiple monitors? If you want to do this with 'external' displays, then the problem is spanning across those individual laptops. With network access, you might be able to fudge something with VNC (although, don't expect great speed on that). Otherwise, I'd say probably not. From what I know, most of those art displays using regular PCs/monitors used specialized software or particular effects not available in a standard configuration to do what they do.

MaxiVista might be what you are looking for (3, Interesting)

Hard_Rock_2 (804967) | more than 7 years ago | (#18728947)

I've not used it myself, but some friends have and it worked pretty well. [] Also perhaps you could bug the synergy team (this is an open source project), although I don't think this feature is something that will be implemented anytime soon... [] Though if you just want to control all the computers from one place, then synergy should work.

Re:MaxiVista might be what you are looking for (0)

Anonymous Coward | more than 7 years ago | (#18729397)

I use MaxiVista when I'm doing some web design and coding projects and it works extremely well. It is limited to 3 extra monitors however and may not suit your needs. It also uses a small bit of bandwidth because it uses the network to extend your monitor rather than video cables (great way to use old laptops though).

Windows? (3, Insightful)

Simon80 (874052) | more than 7 years ago | (#18729005)

Why would it be a requirement that the software has to run on Windows if you're using the laptops sole ly as displays? Even if you'd like to use the display with Windows, the laptops would be able to run whatever you like.

Re:Windows? (2, Informative)

cephalien (529516) | more than 7 years ago | (#18729177)

Assuming that we're talking about a heterogeneous combination of laptops, some of which are unlikely to be anywhere near current, I think Windows (as far as driver support, at least) would be the sensible solution. Since they all likely come with a license for one or the other version, there shouldn't be much of an issue with legality anyway.

Linux would be more flexible, yes, but not when you're trying to get old displays working as fast as possible, along with builtin networking or even wireless, without having to go through a tedious setup for each different machine.

Re:Windows? (1)

Simon80 (874052) | more than 7 years ago | (#18729233)

Well, in this specific context, hardware shouldn't be an issue, since the networking would be wired, and no graphics acceleration would be required. In the absence of those issues, I'd say that Windows would be more tedious to set up, not the other way around. In any case, I'm just nit picking here, since it doesn't look like there's an easy solution on either platform.

Re:Windows? (1)

cnettel (836611) | more than 7 years ago | (#18729701)

No graphics acceleration required? The guy mentioned video, and it's bad enough trying to get it over the network, but a stupid enough framebuffer driver would be the nail in the coffin.

Re:Windows? (1)

Simon80 (874052) | more than 7 years ago | (#18729725)

Sorry, I meant no 3D acceleration - I've come to take 2D acceleration for granted.

Re:Windows? (0)

Anonymous Coward | more than 7 years ago | (#18729629)

License costs alone would be enough to justify using Linux. To remain legal each laptop would need to use the Windows CD it was sold with, and that CD probably isn't bundled with the second hand machine. One would then have to but a copy of Windows for each machine. It's one of the reasons computer clusters (of which this is one) generally use Linux.

An alternative (2, Informative)

Z00L00K (682162) | more than 7 years ago | (#18729045)

is to run Linux on all laptops and execute them all as X servers without any window managers.

Then you have a server that throws X applications onto the laptop displays where you will get just about any look&feel you like.

OK, it's crude and may require some work. The laptops may never be a really good solution anyway. Also consider the cost of additional hardware involved and you may be better off with a good projector or "standard" flat-screen LCD:s connected to a single computer with multiple graphic cards where you stretch the desktop to cover multiple monitors.

It's possible to run multiple monitors under both Linux and Windows without any problems.

Re:An alternative (1)

w4f7z (837544) | more than 7 years ago | (#18729619)

I think the project you're referring to is Xdmx. Here's a decent tutorial [] .

XDMX (2, Informative)

MicklePickle (220905) | more than 7 years ago | (#18729921)

I've tried XDMX on exactly this setup. I had a number of old laptops, (nine to be exact), that I converted to
one large X display. Worked really well. The screen was huge - 3x3 17" laptop screens adds up to a big display. The downside? You have to have a dedicated switch to handle the traffic, (because there is a LOT of traffic - even when moving the mouse the switch goes bonkers). Also, it's slow. Much slower than an individual display, but good for displaying static images.
Once I had it setup I didn't use it much, and in the end just used each laptop as an network mp3 player in each room of the house. Much better use for them.

Re:An alternative (1)

cgenman (325138) | more than 7 years ago | (#18733183)

It's possible to run multiple monitors under both Linux and Windows without any problems.

For me, Windows Media Player seems to crash if you run it on a multiple graphics card/multiple monitor setup. All other video playback was questionable depending on if it used WMP to play back or not. YMMV, but it didn't work that well for me.

Interesting project idea... (2, Interesting)

forkazoo (138186) | more than 7 years ago | (#18729075)

Well, you will need to mount the whole laptop to the wall, and run power and network to each laptop. Each laptop will look a bit different, and laptop displays really aren't meant to be running 24/7, so plan on replacing the laptops with some frequency. That means that the physical build aspect of a project like this won't be insignificant to make it all work smoothly, look nice, be easy to maintain, etc.

Another poster has mentioned a projector. This is certainly the more sensible option, but for a funky project for its own sake, I'll assume that you just want to go with the laptop wall anyway.

First off, don't try to do this with Windows. It'll work very poorly. As for playing videos, you can ssh into each laptop and run mplayer locally to get any gioven laptop playing a video. For multilaptop video playback, you will need to make yourself some scripts that will log into each laptop and run mplayer using appropriate cropping options on the video so that only a portion of it is played full screen on any given laptop. You may also want to check out VLC's network streaming options. You will need quite a bit of bandwidth. I sometimes have issues playing high bit rate video files over my 100 Mb network with just a switch between the client and server, and no other significant traffic. You will also want to avoid any HD. If you are going to build something for playing serious high bit rate HD across 9 or 12 different systems, you don't need to ask slashdot how to do it.

Past that, you probably want to write some additional scripts to do things like randomly show your favorite online scenic web cams, give weather reports, show traffic conditions. But, you are creating custom hardware, so don't look off the shelf for that sort of thing. You pretty much have to roll your own, because there isn't any standard plug and play interface for video walls.

Good luck.

Re:Interesting project idea... (1)

Redlazer (786403) | more than 7 years ago | (#18729857)

I dunno, i find that streaming with VLC works pretty well. Using my 100MB network, while downloading torrents (granted at around 100k/s, but with at least 100 connections per torrent).

I used to have a lag issue when i was using a Belkin router - however, now that i switched to (begrudgingly)a Linksys, i've had ZERO streaming-related hiccups.

Now, im not so sure about the feasability of streaming it across more than 10 or 15 laptops - but an upgrade to a gigabit network would almost certainly solve the problem, assuming you could grab some PCMCIA gigabite network cards.

Wow. Have fun with that.

For what its worth, i think VLC or something similar is your best bet. Most of the other ideas, while cool, would probably not be as effective or seamless(ish). You could also do the really badass Wallpaper setting on some of them, which is always pretty good for a "Oh, thats cool" effect.

Course, good luck getting it set up to stream properly - I had a hell of a time getting it set up to stream, and I can't get it to work with my new laptop.

A few tips would be nice.........


Re:Laptomused as monitor (1)

Jakob Josip (1093979) | more than 7 years ago | (#18895627)

Hi this is an interesting bolog but i was wondering does anyoneknow how to make an old laptop monitor (not conected to a laptop) be used as a monitor for a video game system, I am trying to modify the old N64 with a old laptop screen, if anyone can help me that would be great thanks

Seeking the same answer for Macintosh platform (1)

mole (22725) | more than 7 years ago | (#18729083)

Good question and I'm also looking for answers. I have PowerBook G3 Pismos and iBook G3 12" laptops. I've made stripped down 'picture frames' and mounted them in frames for the wall. I'd really like to build an installation with a mount for grids of say 1x4 or 2x2. Or do a tabletop piece that's 3 panels mounted vertically a closed top. Fitting their logic board, dc board, inverter, assorted bits inside. Extremely cool if able to link the DC power together to have one power cable. But I can't imagine how to get 4 laptop (or even 2) displays running synchronously with a remote command or stream. I'm curious if Quartz Composer could have time snyc hooks embedded in it. The hardware has 8mb of video ram, can run a minimal 10.4 build, 256mb ram and set the energy and display preferences for consistency. I could do 4 14 inch panels or 4 or more 12" ibook screens. This platform doesn't support the Quartz extreme effects but it works fine for Quartz engine which is how all screensavers for OS X are displayed. Animated textThinking out loud, maybe it would fly issuing a shell command to run the screensaver

/System/Library/Frameworks/ScreenSaver.framework /Resources/ reenSaverEngine -front
and building a quartz runtime that say displayed animated text or a slideshow of images. I think they are screensavers that run quicktime files. Or mount the internal microphones (they're on 18 inch cables) in an interesting way and feed the with reaction to audio would be fun too. Apple Documentation on Quartz Composer [] . I'm not much of a programmer, but someone please take a look into it. And for the poster about the projector, I've got one too, but this is a different purpose. 1024x768 laptop screens are far brighter and crisper, installable, tangible.

Re:Seeking the same answer for Macintosh platform (1)

TRRosen (720617) | more than 7 years ago | (#18729511)

they wrote a program to do this at MacHack (now AdHoc) a few years ago I believe it basicly used VNC to spread one desktop across any number of networked machines. I think they maintain a page with the hacks somewhere.

Re:Seeking the same answer for Macintosh platform (0)

Anonymous Coward | more than 7 years ago | (#18749947)

You could always use the fastest of the macs to cut the images into 4s and have each machine grab the correct part of the image. You might even be able to do this with applescript. The slicer could even be done during the time the images are onscreen so there would be no slowdown.

Mirrors!! (1)

thegrassyknowl (762218) | more than 7 years ago | (#18729105)

I had always thought doing something similar to this, but in my dining table. I figured it'd be possible to take one or 2 flat panels and some miscellaneous optics and make a fairly seamless representation of the image appear to be under the glass. Kind of cute if you whack a remote controlled webcam under there and show up your guest's skirts at dinner...

My first though so far was to use mirrors - reflect the display off a mirror kind of like what they do in some of the arcade games. This lets the display appear further from the observer than it really is - hence saving space. You could build some kind of optics system like that for your project to project a reasonably seamless image (apart from colour and size of the images).

Re:Mirrors!! (0)

Anonymous Coward | more than 7 years ago | (#18732451)

Do you actually get guests with skirts to eat with you?

Re:Mirrors!! (1)

thegrassyknowl (762218) | more than 7 years ago | (#18737425)

On a regular basis - contrary to popular belief!

software you might check out (2, Interesting)

sunji.roaoul (1077445) | more than 7 years ago | (#18729249) [] , and it's library [] could be run on the laptop array. Building a laptop hierarchy: 1 laptop recieves the whole 1024*768 and GEM slices four 512*384 screen displays and serves them to a 2*2 grid of laptops on display. or, if you have 21 laptops, you can make a 16 laptop laptop display wall wall. The trick is farming low resolution chunks to the slower machines. The final 4*4 laptop wall only has to have a combined resolution of 1024*768, right? You're not going to get highdef out of this wall.

OLPC put to use (0)

Anonymous Coward | more than 7 years ago | (#18729279)

Or you could build a wall of OLPC's!!! just grapple them away from those pesky kids who wouldn't use them anyway!!

Take a look at HIPerWall (1)

chriss (26574) | more than 7 years ago | (#18729417)

No, it's not what your looking for, just interesting and informative regarding the technical problems.

HIPerWall [] is a 200 Megapixel display, based on 50 Apple 30" Cinema Displays driven by 25 Dual G5 PowerMacs plus one controller. It's a project at the University of California to explore very high resolution displays. HIPerWall is short for Highly Interactive Parallelized Display Wall. The PowerMacs are connected and act as one large display, allowing even video to be split over the whole area. The main problem they seem to have solved is the software to split the display over several separate machines, a problem you will also have if you try this with Windows and laptops, therefore this might be a good place to look for some experience. Apple has a nice project description in their science section. []

Re:Take a look at HIPerWall (1)

Meostro (788797) | more than 7 years ago | (#18734171)

This seems like a much better suggestion than "get a projector". I want to build a video wall too, but the only 2 reasons to do so over a projector are "because" and high resolution.

Yes, I could buy a projector for a thousand or two, but that will still only give me 1.3MP, maybe 2MP if I get a really good one. For the price of a high-end projector I can probably get 4 LCD monitors with some moderate hardware to run them, and end up with a 5MP display that's much brighter and sharper than a projector can ever hope for. My plan is to spend the extra $$$ (probably a lot, but I'm not in a hurry) to get 12 screens running at 1280x1024 (4x3 grid) for 15MP total.

If I can get REALLY fancy and actually have a single program run across this behemoth, I could be playing my favorite FPS at 5120x3072. Or, if I get some better hardware I can run 2560x1920 on each to give me almost 59MP! Fragging never looked so good.

problem (1)

Bastard of Subhumani (827601) | more than 7 years ago | (#18729779)

Isn't it the case that with laptops, the screen is usually the first thing to break?

Re:problem (0)

Anonymous Coward | more than 7 years ago | (#18733545)

nope, it's the battery. that's why there is only 6 month guarantee for those...bastards.

Re:problem (1)

knivesx11 (1085179) | more than 7 years ago | (#18735287)

Especially if you have a sony battery.

GGI (1)

slim (1652) | more than 7 years ago | (#18730077)

Let's assume this is a "because it's there" hack, because as others have pointed out, if all you want is a large video screen, you'd be better off spending the time doing a McJob and spending the proceeds on a projector.

So, you're doing it because it would be kinda cool. Have a play with GGI [] . It's a portable graphics layer with various targets implemented. e.g. there are kernel targets for various graphics cards, a Windows target, a VNC target, etc.

What'll interest you is the display-tile target, which is a proxy target that splits its input into tiles and forwards them to a set of other targets.

  - find the most efficient way you can to display video on a GGI target. Mplayer can do it. here [] is a screenshot of mplayer tiled across a load of X windows via display-tile.
  - Set up each of your displays to be a GGI target that your central box can display to (be it VNC, X, or something more original)
  - configure display-tile to forward the right tiles to the right targets
  - point mplayer at display-tile
  - profit!

The tiles don't have to be a regular size. I'd quite like to see a video wall made up of various sized screens - a 32" TV here, a 17" monitor there, a PSP there, etc... maybe a vt100 in there displaying the aalib target...


3 x 3 wall of monitors with 3 computers, X & L (1)

beachdog (690633) | more than 7 years ago | (#18739253)

There is a fellow running a computer recycling center in Oakland, California who brought to the May 2006 MakeFair in San Mateo a rolling wall with a 9 monitor display. The display was one image partitioned among all 9 displays.

The base of his system was a 3 shelf display rack with casters. It is a common commercial shelving unit.

On the cart he put 3 rows of 3 CRT monitors. Each row of 3 monitors was driven by a salvaged pentium class computer, and each computer had 3 video cards. The video cards pick up an address from the slot they are plugged into, so the video software could send the correct 1/9th part of the image to each display.

The three computers were connected with ethernet cable. The three computers all run linux and X display software. Ethernet is plenty fast enough even on old machines for feeding the displays.

One of the computers was the master. Now what was the software? It was something generic associated with the X display software system but not well publicized. Maybe it was mplayer (which does a number of remarkable video reformatting stunts). See the mplayer documentation files. I remember, he was not using "dual head" video cards (which I have found rather problematic), he just used junkbox video cards and addressed them by slot number. I think X itself has multiple displays in the XF86Config file.

In summary: he had a striking "wall size display". It was portable. It was built using any generic Linux and X. It used recycled computers, video cards and CRT monitors that are available in abundance.

Easy, use DMX. (1)

Ant P. (974313) | more than 7 years ago | (#18730215)

Oh wait... you said windows. Never mind.

yuck (1)

TheSHAD0W (258774) | more than 7 years ago | (#18730699)

I would definitely not try to tap into the video systems for the laptops; keep the whole machine, unhook the hinge, and get a long-enough interconnecting cable to let you flip the display and mount it face up over the keyboard. Yank the hard drives and let the machines boot off the network. Have them all running VNC so you can control them remotely. If they're old laptops you'll want a codec you can detune a bit so it plays the video you want well enough. You'll also need to adjust brightness and color temperature to make the displays more or less identical to the viewer.

This has been done before... (1)

wilw410 (1028040) | more than 7 years ago | (#18731569)

by a cluster computing group at the University of Kentucky called the Aggregate [] . They built a nine laptop display panel that is basically what you are trying to do. It is much more difficult than I thought it would be to do. Here is a video of the panel in action [] . And here is the software they created to do it [] .

Easy and simple. (0)

Anonymous Coward | more than 7 years ago | (#18732939)

> "I am interested in building a video wall as a personal project using recycled old laptops so that I can make use of the display controllers that are already present. Is there free or cheap software that can extend the display on Windows and still be capable of showing different videos on different zones (like, say run a video in one zone while showing a powerpoint presentation in another one) What tools would you use?"

Linux (actually this is a simple designation for GNU software, server, KDE/Gnome DEs, of course, the Linux kernel, but more importantly the OS development process centered on the kernel).

Ah, Windows, you asked? Aham, go to . Only they can help you.

But, from my experience, let's say I'm gonna train my pig to chase falcons before it happens.

Good Luck.

SAGE (0)

Anonymous Coward | more than 7 years ago | (#18738015)

I work in the Electronics Visualization Lab at University of Illinois Chicago, and we have a software to deal with tiled displays called SAGE. []

It also works with VLC. Might be worth a look for you.

Not Windows -- use DMX and Xinerama (0)

Anonymous Coward | more than 7 years ago | (#18743407)

Recent versions of XOrg have DMX (Distributed Multiheaded X) which makes a bunch of separate X servers (usually on different computers hooked up over an ethernet) behave as a single X server running multiple monitors. You run an X server on each machine to run it's display(s), and DMX on one machine to tie them all together. All apps "display" to the DMX X server, and it sends the appropriate info to each "real" X server for display. If you're doing some massive OpenGL stuff and it bogs down, Chromium is supposed to filter the OpenGL so each screen only gets the OpenGL info it needs, otherwise it's sent to all screens.

          By default, these screens aren't treated as one large screen, they're a bunch of separate ones. Enter Xinerama. This makes the screens act as one large screen in the shape you specify (usually square, but they could be all in a line or probably even L-shaped or T-shaped.)

          I have not used DMX, but recently hooked 5 screens to a single PIII-800, using 5 Nvidia TNT2s. These were all in a left-to-right line. The OpenGL screen savers ran like crap (since I was not uses the NV driver, so no 3D acceleration..) but everything else worked great. DMX looks VERY easy to setup. I actually had 7 heads hooked up, but the (AGP) dual-head G400 didn't play nice with the rest so I left it out.

          *DON'T!!!* use a bunch of laptops/notebooks for this screen. If you don't already have them, the used market for them is stupid expensive, they're highly unreliable, and as others have said, the appearance will be very ugly and non-uniform. These will not have ethernet, so you'll have to dig up a bunch of PCMCIA cards and dongles, or god forbid run wireless.. you'll run out of bandwidth quick that way 8-). They might not have fast enough video hardware to play full-screen videos either. Cheap ones tend to have like 8-32 megs of RAM too. You probably can't even get a P2 notebook for what a used LCD will cost you, and you can get LCDs that are more uniform in appearance, even if they aren't the same brand. If you're running even something large like a 6x6 grid, you could run this off 6 desktops if you get some with 6 PCI slots (or 5 PCI and 1 AGP) and old video cards. A 3x3 could run off just 2 computers. You could cram even more screens per computer if you want to run dual-head cards.
Check for New Comments
Slashdot Login

Need an Account?

Forgot your password?