Q: how do you add cinema display to imac

You'll want to see if your iMac has a Display Port plug, and if it does, then you can simply plug the Cinema display into it.

If the iMac doesn't, it may have a mini dvi port, and that would require a mini dvi to dvi adapter from Apple, along with a DVI to Display port adapter.

Your best bet is to find out the specs on your iMac, and one good way to do that is to get your serial number and check it on this site:

http://support.apple.com/specs/

If you still have trouble, please post the model of your iMac or at least the serial number of your iMac so we can help you figure out what you have and what kind of adapter you may need.

Quite a few older iMacs simply can't connect to the Cinema Displays.

Hi, I have the same question. I just bought a new 27" imac http://support.apple.com/kb/SP623 which is supposed to have a Mini DisplayPort output (is this the little port underneath the power plug?). I also have a 2005 23" cinema HD display, which came with the 90w power adaptor, which has the power cable, dvi port, a firewire and a usb cable. the monitor seems to have the same small port under the power outlet as the iMac. Can anyone tell me what I need to use 23" display as my 2nd display? thanks

I think what needs clarity here is the new iMacs etc have a mini display port, which is the same port as the thunderbolt port. i.e. if you havethunderbolt, you have a mini display.

now you need this: http://store.apple.com/us/product/MB570Z/A

cheers

I bought the adaptor but my iMac still won't recognize the cinema display. Also, what do I do with the USB and firewire connectors? I can't connect firewire because my imac is newer than the cinema display. I was thinking that the extra two connectors weren't necessary with thunderbolt. Are they?

Make sure the adapter's Mini DisplayPort plug is pushed in all the way (no metal showing).  You should plug in the USB.  The FireWire isn't needed.

Thanks, Malcom! I unplugged the connections and re-connected, re-started, and then it worked. I have the display adapter and the USB plugged in, and the firewire is just hanging loose.

That mini display post and thunderbolt are the same I knew, and pluging in my old 30 inch Cinema display in both my iMac and new MacBookPro retina works fine. The problem is that it is impossible to get a screen resolution larger than 800*600 on the extra display! The same problem for both machines. The MacBookPro I discovered has an HDMI port and when I connect that to an external display I get full resolution. But since the old Cinema displays have reverse gender on the DVI from all other displays it is impossible to use a DVI-HDMI adapter.

The iMac has no HDMI so there only mini display port can be used and then only at 800*600 resultion. This is quite ridiculous! When I bought my iMac I choosed a better graphics card that should without problem be able to driva 2 displays at full resolution.

Could it possibly be some new driver that needs installing to get full resolution on display port ?

You need a dual-link Mini DisplayPort to DVI adapter to get full resolution on a 30" display.

<http://store.apple.com/us/product/MB571Z/A/mini-displayport-to-dual-link-dvi-ada pter>

Aha! That actually makes sense! :-). Thanks Malcom!

Thanks for any suggestions on the following: I've done this all, with the 23 inch HD display and the 23 inch is dark. The cursor does go off screen on the main iMac display, leading me to believe that it's working but I just can't see it. Here's what the display preferences look like:

FWIW the mini dvi display that comes with the USB that works with the MBP also works with a new iMAC 27" (tTO) 30" Apple Cinema Display (2004-05). FWIW Wow, what a nice display they made back in the day. I can see why some at Apple still used in the design dept as of 2015. Mine is just dimmer than the new 5k iMac.

To connect a 30" Apple Cinema Display to newer Macs, use an "Apple Mini DisplayPort to Dual-Link DVI Adapter."

The 30" ACD has 4 cables that come out of the back:

(1) Dual-Link DVI

(2) USB 2

(3) Firewire 400

(4) Power

The adapter's USB port allows the adapter to supply power to the 30" ACD's two USB ports. However, the adapter does not have a socket for Firewire 400, so the Firewire 400 cable from the monitor goes unused, and thus, the Firewire ports on the back of the 30" ACD are rendered useless.