Will Mountain Lion support a VGA splitter

I'm using the Tripp Lite VGA splitter linked to in my previous post,

The iMac is set up to run ProPresenter with the control display on the iMac, and outputting the presentation display through the VGA to the splitter, to send duplicate images to both displays.

Here is the set up:

iMac -> Mini DVI to VGA adapter -> VGA splitter -> 2x Optoma projectors (via VGA)

To the mac this is only 2 displays, as the signal is being split after it leaves the iMac

We did not have to install any drivers for the iMac to recognize the adapter, I've contacted Tripp Lite and they don't create any drivers for their devices as they are built to run under generic VGA drivers.

I hooked up my mid-2011 iMac running Mountain Lion by using a mini-display port to VGA adapter and it works fine. The only difference here is that I'm using a mini-display port adapter instead of a Mini-DVI.

Thanks for the suggestion, as mentioned before Tripp Lite does not supply or require any drivers for the VGA splitters because they are built to run under generic Plug-n-Play VGA drivers. The splitter is merely taking one signal and duplicating it so that both projectors are displaying identical images. There's no funky magic going on at all.

The problem is that the iMac is not recognizing that a secondary display is being plugged in under Snow Leopard. I've run all possible updates on the iMac and haven't found a solution yet.

TheSmokeMonster wrote:

So what did their support team say when you asked them if there was support for ML?

From Tripp-Lite

The B114-004-R is operating system agnostic, so if it has issues with individual versions of OSX that would indicate conflicts with how the display drivers are telling the computer to pass signal. There is no reason why it should not work with 10.8 (or any other version of OSX) given that there is no software that goes with it.

I've done the SMC reset as well as the PRAM and NVRAM, no dice.

After going through Optoma's support just to make sure, it couldn't be anything with the projectors I called Apple and spoke with a Senior Advisor. Due to the fact that the VGA splitter works with my mid-2011 iMac, but not with the 2008 iMac his best guess is that the error must have something to do with the handshake protocols that allows the iMac to detect that there is something attached to the external display. Unfortunately there is no way to 'brute-force' the iMac to send video without receiving a handshake confirmation. The "Detect Displays" option only makes the iMac look for a display, but it won't send the signal without a response.

The option at this point is to either find a different splitter and try that, or downgrade the iMac to Leopard (which requires a full wipe and re-install.

Not the solution I had hoped to find, especially when the iMac, VGA splitter, projectors, and presentation software are individually listed as Mountain Lion compatable.