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Sound-producing LCD Screens

Posted by Hemos on from the dude-we-can-have-an-lcd-floyd-show dept.

haakon writes "The New scientist have a story about getting LCD screens to produce sound. I wonder if I can hack a X server to do that on my laptop? " Mmm...with this SGI flatscreen, and Rob's as well, I think we're to be having a concert - tickets go on sale Friday.

1 of 36 comments (clear)

  1. We already knew monitors emit sound! by watanabe · · Score: 3

    This is somewhat related --

    Markus Kuhn, a researcher at Cambridge University published a paper in 1997 on using monitors to emit radio frequencies which could be picked up by a short wave radio. His goal was to provide covert information dissemination techniques that worked solely in software. (His other goal was to provide information protection techniques that worked solely in software. I think the dissemination stuff is cooler. He's a good guy, though in my opinion.)

    The upshot of his research is that
    a) A computer monitor can be made to make certain visual patterns which will sound like something on a nearby radio
    b) You can get about 6 bytes per second like that, which is small, but enough to steal passwords, etc and transmit them at night when everyone's screensaver is running to a nearby hidden radio.
    c) He did this in Linux with XFree86.

    I find this totally cool. He also suggests that a graphics card could make a radio transmitter; this is also extremely cool. You can now publish over the airwaves. That would make a great icecast/shoutcast plugin...

    The paper is at http://www.cl.cam.ac.uk/~mgk25/ih98-t empest.pdf.
    His homepage is at http://www.cl.cam.ac.uk/~mgk25.