Connecting an old iMac to my new one (as extra monitor)

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Level 1

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Connecting an old iMac to my new one (as extra monitor)

Hi gang.

I have a brand spanking new iMac 2019 that I want to connect to a very old 2009 iMac, to use as an extra monitor.

The old mac has a MiniDisplay port and my new one Thunderbolt 3 ports. So I bought an adapter, thinking it was the right kind, but it's not. I ended up getting a MiniDisplay port to HDMI cable when I was looking for a MiniDisplay port to Thunderbolt 3 cable (which I can't seem to find anywhere).

So my big question: Can I still use this cable and perhaps get a hub or something so that I can join my two machines? If not, can someone please tell me the exact cable I would need?

Thanks!

B

iMac 27", macOS 10.15

Posted on Mar 23, 2020 6:32 PM

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Answer 1

Top-ranking reply

Malcolm J. Rayfield

Level 7

23,053 points

Mar 23, 2020 7:39 PM in response to Belly Buckle

Use your iMac as a display - Apple Support

If you have a 27-inch Late 2009 iMac it will work if you use a USB-C to Mini DisplayPort cable, such as:https://www.startech.com/AV/display-and-video-adapters/usb-c-video-adapters/usb-c-mini-displayport-cable~CDP2MDPMM6B

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Answer 2

Belly Buckle Author

Level 1

15 points

Mar 24, 2020 5:24 PM in response to Malcolm J. Rayfield

Hi Malcolm - me again.

So I've been looking to see if I can find something less expensive. Also, since I already purchased a minidisplay to HDMI cord, I am wondering if I could use it with THIS instead so that both can work together to hook up my imacs:

https://www.amazon.ca/gp/product/B01M6C49X2/ref=ox_sc_act_title_1?smid=AONZ4ZXCX5VHY&psc=1

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Answer 3

Mar 24, 2020 5:33 PM in response to Belly Buckle

No. The Mini DisplayPort to HDMI adapter you have, and the Amazon USB C to HDMI adapter, are both for connecting HDMI displays to computers. They do not work in reverse to feed HDMI video to a computer.

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