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Does anyone know of any software/hardware configuration that will allow you to preview/view the contents multiple monitors on one monitor? Let's pretend:

  1. I have two monitors hooked up to one pc, Monitor A and Monitor B. The monitors are not near each other.
  2. I'd like to be able to preview/see what's displaying on Monitor B on Monitor A

I haven't been able to find much about this, but I imagine it may not currently be possible to access/emulate video output going out of a video port in software.

However, wouldn't it be possible to capture display data generated by the OS kernel or data getting passed down to the display adapter driver?

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I'd love to know if this is possible. +1 – Shinrai Mar 11 '11 at 21:06
up vote 3 down vote accepted

One solution that accomplishes this task is to run a VNC server on the pc with multiple monitors, then connect to that pc using a VNC Client(that connects to the VNC server running on localhost) on the same pc.

I tested this with a couple VNC servers, and got good results with TightVNC.

I also created a guide with instructions and screenshots: Multiple Monitors on One Screen

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Very cool! With the standard zoom feature, VNC naturally solves this problem, even though it's not designed for this :-) – netvope Dec 8 '11 at 16:07

Depending on how you are running the video (svideo, vga, hdmi) you could simply split the video and run one into its designated monitor and the other into a video switch. You wouldnt get pip but you could swap between feeds fairly quickly. This is actually how we do it at work for a computer/security camera feed/computer/fee computer setup.

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This is a good idea, but the solution should be strictly software-based. – dhulihan Mar 15 '11 at 4:26

My hacky solution - change monitor A to one with PIP (picture-in-picture) and then get a Y-shaped video lead. No idea if such a thing exists or not.

If not, a port replicator style thing as is often used in electronics stores to demonstrate computer monitors should do it.

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Would it work to install VNC servers (essentially remote desktop) on all of the machines whose monitors you want to view, then run several instances of a VNC client on the monitoring computer? You might want to check out software like VNC Thumbnail Viewer (I've never used it, but it looks nifty) which shows a thumbnail of each machine you have VNC running on, then you can click to enlarge the image.

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That would work with a multiple-terminal system, but in this scenario, I'm thinking about one terminal with multiple monitors connected to it. I wonder if there's a vnc/rdp server(that you would run locally on the terminal) that would allow you to see the multiple monitor instances on the remote/client terminal(which would be itself). – dhulihan Mar 15 '11 at 4:32
Ok, I wasn't clear that it was all for the same machine. Hmm. I'll edit my post if I think of any other solutions. – nhinkle Mar 15 '11 at 4:55
K, thanks. Sorry about the confusion. – dhulihan Mar 15 '11 at 20:56
Using the VNC approach, I got an approach working pretty well with TightVNC. I also made a guide for it. I'll add a new answer with the details. Thanks for your inspiration! – dhulihan Mar 15 '11 at 23:40

You could use a KVM switch if I understand correctly.

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Sorry, what I mean is the viewing of multiple video ports/sources at the same time on one screen(like a pip setup or similar). – dhulihan Mar 12 '11 at 4:32

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