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No DisplayLink shenanigans necessary. Just one Thunderbolt 3 dock. :)
OK. I just assumed that Apple had gimped the 2012 13" just like they did the 13" M2 I am using.

The difference is your 2015 Retina MBP had two Thunderbolt 2 (DisplayPort) outputs and one HDMI output; connecting two external displays was a piece of cake.
OP's 2012 non-Retina MBP only has one Thunderbolt 1 output that carries two DisplayPort streams, so a Thunderbolt 3 dock is necessary to extract them and drive two displays.
Gotcha now. Thanks. Didn't realize that could be a thing.
 
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The limitation to one external display on the base Mx models is…uhh…peculiar.
Yeah and stupid me, I had assumed based on the 2015 MBP, that work would get the same size. So, I found out about that limitation real quick. I could have dealt with it better if Apple allowed two displays to count while the Mac is in clamshell mode because that is how I use the work Macs. But no. Apple says, one display plus the laptop display, period.

Whole lot of agonizing Google searching and expensive dock/adapter buying from the company to work around that. Fortunately, they were willing to pay for it.
 
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I could have dealt with it better if Apple allowed two displays to count while the Mac is in clamshell mode because that is how I use the work Macs.
Funny thing is the 13“ 2011 MBP allows this: hook up two external displays — and the internal one goes off.
 
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OK, so again I am not OP and I am operating a 2023 M2 MBP. 2015 MBP is behind the 2023. Both of these are work issued.

A black object dragged around a QuarkXPress 2022 document with a black background (I zoomed in). Both monitors.

No green static.

Don't know what to say, I cannot reproduce green static with these Club adapters. The possible explanation, as I mentioned above, is that both my displays were part of that silent update and are HDCP ON.
The black object (window) needs to be dragged around a non-black background. In the example pictures in the club-3d thread, the background was the standard Windows 10 desktop wallpaper.

I was asking specifically about how to connect dual ACD's to a single MiniDisplayPort as I couldn't find anything already posted on here. There's a bunch of threads already that talk about connecting to USB-C.
macOS doesn't support DisplayPort MST so you can't connect two displays with a MST hub.
Good news though, your Mini DisplayPort is actually a Thunderbolt 1 port. To connect two displays to that, you need to connect two Thunderbolt 1/2 docks, or connect one Thunderbolt 3 dock.
The DisplayPort to Dual Link DVI adapters can get USB power from the Thunderbolt dock.
The USB-C to Dual Link DVI adapter don't require extra USB power because the USB-C port has extra power.

Before the M2, I used the 2015 MBP that is in one of the pics. That's fairly close to your Mac I believe (2012 I think you said). To get my two Cinemas to work with that MBP I had to use two A1306 Apple adapters. For power, you plug them in to those little iPhone power bricks (the square ones).

But my 2015 MBP was a 15 inch, and Apple may have gimped your 2012 because it's a 13" right? Apple gimped the 13" that work gave me, which is why I have to use that dock I linked to that has DisplayLink.

But because I mentioned I use Club adapters that brought out a side discussion and I apologize for that.

Assuming I've read your situation correctly, you're going to need a Thunderbolt 2 or 3 dock that has DisplayLink. I don't have any recommendations for that. But you can get at least one display working with the A1306 and whether there was a silent update or not to your Cinema Display that Apple adapter should work.
DisplayLink isn't required unless the Thunderbolt port doesn't actually support two displays.
 
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The black object (window) needs to be dragged around a non-black background. In the example pictures in the club-3d thread, the background was the standard Windows 10 desktop wallpaper.
I'll take another shot at it tomorrow.
 
The black object (window) needs to be dragged around a non-black background. In the example pictures in the club-3d thread, the background was the standard Windows 10 desktop wallpaper.
No green static. The flashes you see are the box lining up with InDesign's smart guides, so that isn't anything.

 
Apple‘s miniDP>DL-DVI adapter (A1306) would need a passive adapter in that case, yes. A TB3 dock that doesn’t have a (mini)DisplayPort output is no good for this setup, neither is one TB1/TB2 dock since you can’t run two monitors off it.


I have no experience with them but this list is a good starting point. Make sure it has a detachable (removable) TB3 cable because you need to plug the TB2-to-TB3 adapter into it.
Hey. Would this do the trick? https://www.wavlink.com/en_us/product/WL-UTD21_UTD21H.html
 
It gets no signal for the ACD connected to the USB-C via a USB-C to mini display port adapter.
Of course not. The USB-C of the UTD21 does not support DisplayPort Alt Mode. You have to use the DisplayPort outputs of the UTD21.

Update: The Wavelink UTD21 does not work for this. It recognises the ACD plugged into the display port but the screen remains black.
Use SwitchResX to examine what timing is being sent to the ACD. Select a correct timing (one from the EDID - either 1280x800 or 2560x1600).
To be clear, you have two Apple Mini DisplayPort to Dual Link DVI Adapters, each connected to a DisplayPort output of the UTD21 using a DisplayPort to Mini DisplayPort adapter and/or cable?
 
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Of course not. The USB-C of the UTD21 does not support DisplayPort Alt Mode. You have to use the DisplayPort outputs of the UTD21.


Use SwitchResX to examine what timing is being sent to the ACD. Select a correct timing (one from the EDID - either 1280x800 or 2560x1600).
To be clear, you have two Apple Mini DisplayPort to Dual Link DVI Adapters, each connected to a DisplayPort output of the UTD21 using a DisplayPort to Mini DisplayPort adapter and/or cable?
Yes that's correct.
 
Of course not. The USB-C of the UTD21 does not support DisplayPort Alt Mode. You have to use the DisplayPort outputs of the UTD21.


Use SwitchResX to examine what timing is being sent to the ACD. Select a correct timing (one from the EDID - either 1280x800 or 2560x1600).
To be clear, you have two Apple Mini DisplayPort to Dual Link DVI Adapters, each connected to a DisplayPort output of the UTD21 using a DisplayPort to Mini DisplayPort adapter and/or cable?
These are from both ACD's
 

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  • Cinema HD.txt
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  • Cinema HD (2).txt
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EDID's - check.
Now perform the other steps/actions described in my previous post.
From the information from Amethyst1 post...

"The dock will have two DisplayPort outputs: one straight (mini-)DisplayPort output and another one "hidden" in the second (downstream) Thunderbolt 3 port which is a USB-C port.
Plug the first 30" ACD into the dock's (mini-)DisplayPort output (using a male DisplayPort to female miniDisplayPort adapter if necessary) using the first A1306.
Plug the second 30" ACD into the dock's second (downstream) Thunderbolt 3 port using a male USB-C to female miniDisplayPort adapter and the second A1306."

As it turns out the second USB-C port on the Wavelink is USB 3.1, not TB3.

Last edited: Feb 13, 2024
 
What I said here applies to most TB3 docks I’ve seen, but the Wavlink does things differently. It still has what’s necessary though: two DisplayPort outputs.
Right. The Wavlink hides the downstream Thunderbolt port and uses it for the 2nd DisplayPort output.

The simplest Thunderbolt 3 device with two DisplayPort outputs is Thunderbolt 3 to Dual DisplayPort adapter.
https://eshop.macsales.com/shop/owc-thunderbolt-dual-displayport-adapter

A Thunderbolt 3 dock like the Wavlink might be preferable in your case because the Apple Mini DisplayPort to Dual Link DVI adapters require USB ports to provide power to the adapter.

How do I go about that?
It's like breathing. You just do it...
Or, In SwitchResX, double click the current resolution selected for the 30" ACD. Do the numbers in the timing info match the numbers in the EDID?
Apple 30" Cinema HD 2560x1600 timing info.pngApple 30 inch Cinema Display 1280x800.png
 
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Right. The Wavlink hides the downstream Thunderbolt port and uses it for the 2nd DisplayPort output.

The simplest Thunderbolt 3 device with two DisplayPort outputs is Thunderbolt 3 to Dual DisplayPort adapter.
https://eshop.macsales.com/shop/owc-thunderbolt-dual-displayport-adapter

A Thunderbolt 3 dock like the Wavlink might be preferable in your case because the Apple Mini DisplayPort to Dual Link DVI adapters require USB ports to provide power to the adapter.


It's like breathing. You just do it...
Or, In SwitchResX, double click the current resolution selected for the 30" ACD. Do the numbers in the timing info match the numbers in the EDID?
View attachment 2437426View attachment 2437427
Yes they do.
 
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