Re: tictech: connection questions

From: Graham Ford (fordgj@u.washington.edu)
Date: Mon Nov 25 2002 - 16:35:34 PST

  • Next message: Mark Ahlness: "RE: tictech: connection questions"

    -tictech message:

    I recommend an external solution that converts VGA to a television video
    signal. Mainly, because it is portable and does not require drivers or
    other software on the computer. Now, quality is an issue whenever you are
    converting from VGA to video. First, television is interlaced whereas
    computer screens are progressive scan. Basically, old televisions were not
    fast enough to display the required 30 fps (NTSC is actually 29.97), so they
    interlaced, so it writes every other line and then returns to the top and
    draws the other half of the image. This issue with this is that any single
    pixel horizontal lines (such as those that are part of text) will flicker.
    In fact, anything small is practically impossible to read. If you are going
    to do this, first figure out what you want to display. Powerpoint
    presentations with big fonts work the best. Also, NTSC television is
    limited to a resolution of 720x480, so you can't show big things without
    shrinking it down and dropping pixels. Often making fonts bigger in
    documents and presentations helps, but you can show less because of the
    limited resolution. I have used some higher quality scan converters where
    the device zooms in on regions of computer screen. The particular box I
    used could even follow the cursor. My advice is to not go too cheap, as you
    really do get what you pay for with these things, and make sure you pay
    careful attention to the features.

    Now, as far as your mac, you can easily change it to mirror the video on
    each screen. To do so, open the monitors control panel and go to 'Arrange.'
    You will see a spatial representation of the two monitors. Drag one monitor
    onto the other one. Voila. Also, if you have the control strip turned on,
    there is a module to turn mirroring on and off. This has been the same on
    the Mac OS since I can remember.

    To connect the old Apple ADB connector to a USB port, you can get a Griffin
    iMate. Unfortunately, I don't think this adapter would work on the PC,
    because I think it requires a driver and that makes the MacOS actually see
    the ADB port.

    Regards,
    Graham Ford
    Network Administrator
    Highland Park Elementary
    gjford@seattleschools.org

    > From: "Doud, Greg" <gidoud@seattleschools.org>
    > Reply-To: tictech@learningspace.org
    > Date: Mon, 25 Nov 2002 14:09:52 -0800
    > To: "'tictech@learningspace.org'" <tictech@learningspace.org>
    > Subject: tictech: connection questions
    >
    > -tictech message:
    >
    > Dear Folks,
    >
    > Greg at John Hay here. I am looking for a way to hook up some of the levy
    > student Dell computers to the TVs in the classrooms. Has anyone done this
    > with a cable or adapter yet? Or, will I need to install a video out card?
    >
    > I have the same questions for a projection device. I can unplug the
    > monitor, and it will project just fine, but I want to show both screen and
    > monitor.
    >
    > Finally, I have some Alphasmart 2000s, with the round serial connections
    for
    > Mac and PC. I would like to find a cable that connects these to the USB
    > ports on the front of the Dells. I am trying to avoid the PC Y cables
    that
    > connect in back, because I need them to be portable (to move around the
    > building with the Alphasmarts). Any ideas?
    >
    > Thanks in advance for all the suggestions!
    >
    > Greg Doud
    > John Hay Elementary
    > gidoud@seattleschools.org
    >
    > -end tictech message. To join, leave, or visit
    > the message archive, go to tictech on the Web:
    > http://www.earthdaybags.org/tictech/
    >

    -end tictech message. To join, leave, or visit
    the message archive, go to tictech on the Web:
    http://www.earthdaybags.org/tictech/



    This archive was generated by hypermail 2b29 : Mon Nov 25 2002 - 16:44:35 PST


    Learning Space Development Server
    This page under development for The Learning Space
    Copyright ©1996-2000 by the Authors - All Rights Reserved
    Unauthorized use prohibited.
    This site was whacked using the TRIAL version of WebWhacker. This message does not appear on a licensed copy of WebWhacker.