Apple Cinema Display 30

[DRDR]

Out of nostalgic reasons I recently bought a used 30-inch Cinema Display and connected it successfully to a Mac Studio M1 Max, a MacBook Air M4, an iPad Pro M2, and an iPad Pro M5. The display still looks fine. This post is for those of you wondering how to connect it:

Club 3D Dual Link DVI-D to USB-C converter

This converter works just fine. You have to make sure to get the version with HDCP off (Edit: Later versions of the display might have HDCP support). This means that it will work fine but will not show copyright-protected streams (e.g. Netflix or Amazon Prime Video). The model I used is: CAC-1510-A

How the display looks in 2025

I made a little video of the experience:

How to control the brightness from inside macOS

macOS 26 no longer supports the control of the brightness of this old display with a software slider. I therefore made a little utility which lives in the menu bar and uses USB to show and control the brightness:

https://humuku.de/apps/drdisplaybrightness/

The App can be used to control the Apple Cinema Displays connected by USB to the computer.

The app cannot be put into the App Store, because sandboxed apps cannot use USB for control. But as the App is notarized by Apple it can be run without security problems after download.

But in any way: It is just a free little tool that you use completely on your own risk. I asked the A.I. for some hints and then went to work in Xcode with Swift. So do not expect wonders of software engineering. I will try to keep it updated as long as I am using the display.

 

[Noot]

Nice!
Little addition: The early models were indeed without HDCP, but the later models do support HDCP. So first check which model you have before getting the adapter.

 

[DRDR]

Thank you. That is interesting information. How can we check if the display support HDCP or not?

 

[EugW]

Thank you. That is interesting information. How can we check if the display support HDCP or not?

It was ~2007 when the 30" ACD got HDCP support.

If you have an Intel Mac you can use @joevt's EDID app to output the product ID. If it is 9221 then it supports HDCP. Or at least that is one model that supports it. The output will also indicate that "HDCP is supported".

-----------------------------------------------------
------------------- MAIN EDID BLOCK -----------------
-----------------------------------------------------

	EDID Version........1.3
	Manufacturer........APP (0610)
	Product ID..........37409 (9221)
	Serial Number.......

	Manufactured........Week 17 of year 2007
	Max H Size..........64 cm
	Max V Size..........40 cm
	Gamma...............2.20


-----------------------------------------------------
------------ EXTENSION EDID BLOCK   1 ---------------
-----------------------------------------------------

DI-EXT: Digital Interface Extension:
------------------------------------
	Version: 1
	Digital Interface:
	Supported Digital Interface: DVI Dual Link - High Resolution
		Data Enable Signal Usage Available
		Data Enable Signal High
		Edge of Shift Clock: Not specified
		HDCP is supported
		Digital Receivers do not support Double Clocking of Input Data
		Packetized Digital Video is not supported
		Data Formats: 48-Bit MSB-Aligned RGB (Dual Link - High Resolution)
		Minimum Pixel Clock Frequency Per Link: 1 MHz
		Maximum Pixel Clock Frequency Per Link: 165 MHz
		Crossover Frequency: 165 MHz

However, another way to do this is to go to System Report and look for the monitor in the USB Device Tree. If it says 0x9221 under the Product ID then it supports HDCP.

 

[DRDR]

Thank you very much for this detailed information.

I added the EDID reading and decoding to Version 1.1 of my DR.DisplayBrightness App.

I appreciate your feedback.

 

[EugW]

Thank you very much for this detailed information.

I added the EDID reading and decoding to Version 1.1 of my DR.DisplayBrightness App.

I appreciate your feedback.

Nice, it works! I assume the brightness keys don't work for this, right?

However, I see this is only for the Cinema Displays. This is with the LG 6K:



Also, Tahoe 26.1 is required.

 

[DRDR]

Thank you for testing. I will check if I can get the information for other displays.

 

[DRDR]

Yes, it only works for Cinema Displays:

• Apple Cinema Display 20", 23" & 24"
• Apple LED Cinema Display 24"& 27"
• Apple Cinema HD Display 30"

I modified the App to show more and more exact information. It is now compatible with macOS 26.0. Thanks for checking! I also changed the message, when no compatible display could be found.

Decoding the proprietary EDID block posed some challenges. But I am confident that the output is now correct for Apple Cinema Displays. Using the brightness keys might also pose a challenge...I will take a look.