The manual for the VSA12, indicates it is an active buffer device.
It is a distribution amp, that runs off a 9V wall adapter.
And what that should do, is make two identical copies of the
original video signal. If the smartboard and the monitor don't share
a common resolution, then one of them may indicate "out of range".
http://www.rextron.jp/products/manual_e/REXTRON_VSA248.pdf
Another small detail, is the connection of DDC. There is a serial
clock and data interface on the VGA cable. Computer monitors have
a table of resolutions stored in them, which can be read out. That
is how the computer figures out what resolutions to use (in theory).
When there are two devices connected, you'd hope that one of the
ports is the one that has the DDC connected. If you look in the
Display control panel, maybe you'll see one of the devices named
by its Plug and Play information. And that would tell you that
the computer is able to see the serial data on the DDC interface.
In any case, you'd still have to select a resolution and refresh
rate they both like.
This program allows you to see whether any Plug and Play is coming
across or not. It might tell you which device is providing DDC
info, if any is actually coming across. Not all VGA devices have
such an interface. For example, a projector might not have DDC
on it, just the RGBHV signals.
http://www.entechtaiwan.com/util/moninfo.shtm
If you only have the one VGA output on the computer, you can produce
just the one signal with that. You can feed identical copies to both
display devices, but you won't have "extended desktop", "clone" or
any other video driver functions like that to work with.
What you need, is a video card. You mentioned the words "ultra-slim"
above - eek! That severely limits what you can do with that computer.
And page 1 here, shows the bad news. This is almost a laptop, in terms
of expansion capabilities.
http://h18000.www1.hp.com/products/quickspecs/13029_div/13029_div.PDF
But don't despair. There is still hope. They make USB2 video display
devices. You won't be playing 3D games on it, but for mostly static
display output, it'll be fine. I believe these things use a degree
of data compression on the USB cable, which helps compensate for the
30MB/sec or so you might expect to get on a USB2 cable.
I like the reviews on this site, because they can give some background
on the device in question. The chip inside this one is made by
DisplayLink. It is possible an earlier version had a VGA output. This
one is DVI (and I didn't notice if it said DVI-D or DVI-I).
http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16815101001
There are more examples here. This is the company that makes the chip,
and this page has some other suggestions of hardware that uses the
chip.
http://www.displaylink.com/shop/index.php?product=5
Perhaps if you can find something like that, where you are, you
can set up a second independent video output on your ultra-slim
that way. Just don't expect to be playing 3D games on it.
Not all the devices of that type, use data compression or incremental
update techniques, to drive the display. Some of the earlier devices,
would be relatively dumb, and a bit slower. Also, the output
resolutions of earlier attempts at this kind of technology, may be
lacking (like 1024x768). The DisplayLink may be one of the first
"barely acceptable" solutions, while some of the earlier designs
are only fit for the nearest garbage dumpster.
There was one LCD computer monitor, that offered a USB connection
on the monitor for video purposes. It uses a DisplayLink chip
and one other neat feature it had, was the monitor had a copy
of the driver stored in flash memory. When you plugged the monitor
into the computer, an Autorun in the flash memory, would be automatically
run by the computer, and within a few seconds, you'd have a video
output on the screen. But that only worked for perhaps one OS,
and what was stored in flash didn't satisfy all possible OSes.
Still, it is an example of trying to integrate the function,
right into a monitor.
http://www.everythingusb.com/samsung_syncmaster_940ux_11970.html
Here, you can see that Samsung monitor has two functions on the
USB cable. "Ubisync" is the video display interface in the monitor,
while the other one is the USB Mass Storage (flash) that holds
the driver code.
http://www.everythingusb.com/images/list/samsung940uxusbdevmgmt.jpg
Once you get something like that set up, that should give you an
independent display.
*******
There is yet another solution, but it relies on the characteristics
of the GPU in the computer. Matrox makes a number of different models
of display splitting devices. For example, imagine the computer had
the ability to drive 2560x1024 out on the VGA cable. The Matrox device
splits the output down the center, sending the left half to one VGA
output (1280x1024) and the right half to a second VGA output (1280x1024).
It means the two display devices should like the same kind of signal,
but at least in that case, you have an "extended" desktop of sorts.
+------------------+ +-----------+ +-----------+
| 2560x1024 | ===> | 1280x1024 | + | 1280x1024 |
| | | | | |
+------------------+ +-----------+ +-----------+
You can start checking compatibility here.
http://matrox.com/graphics/en/support/gxm_main/
I think this one might be a (wide) VGA in, to two VGA out.
http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16815106015
This article, shows a picture of what is inside the box.
http://www.anandtech.com/displays/showdoc.aspx?i=2621&p=2
And this article, is for the triple-head version, which
requires the computer to drive out an even wider signal
to make it work.
http://www.anandtech.com/printarticle.aspx?i=2806
Have fun,
Paul
