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Deccr

macrumors member
Original poster
Nov 29, 2020
56
39
As I understand it the M1 macs do not support target display mode. I have a 2011 27” iMac which I would like to replace with a new M1 Mac mini. However reading these forums it appears my iMac will not function as a display for the mini in target display mode (through thunderbolt).

It occurred to me, as a temporary measure, I could use a dummy DisplayPort emulator plug (through a thunderbolt dock - like the Caldigit TS3+) to force the mac mini to ‘see’ a QHD display. I could then use ’screens’ to view this QHD display on my iMac. I was thinking of something like this:


If the link is incorrect, I’m specifically thinking of the following option:

DP - DisplayPort display emulator EDID emulator Plug (fit Headless 2560x1600@60Hz)​


Obviously this is a fudge and will not be an ideal way to use the Mac mini. However it should allow me to keep using my iMac as a display, with the speed of the m1 mini.

Is anyone able to test or verify if something like this would work? Or have any thoughts on this. I’m not interested in buying a new monitor right now, so I’m not bothered about monitor suggestions.
 

Deccr

macrumors member
Original poster
Nov 29, 2020
56
39
Update: I got a DisplayPort plug but that didn’t seem to work, either through the CalDigit TS3+ or a USB-C -> DP dongle.

This HDMI dummy plug does work, and can be forced to 2560x1440 to match the iMac resolution: https://www.amazon.co.uk/dp/B087QDCZ4L/ref=cm_sw_r_cp_awdb_imm_t1_wbY3FbP35W05F?psc=1

I’ve also ordered a USB-C Luna Display dongle, to try Mac-to-Mac mode and see if that is useable.

Finally, I’m tempted to take the nuclear option: gut the iMac and install a dedicated driver board, such as this: https://www.ebay.co.uk/itm/HDMI-DVI...-2560-1440-LM270WQ1-SD-E2-panel-/193390883105

The iMac will no longer be useable as a computer, but would be turned into a dedicated monitor. Tempting but I know it will be a lot of work.
 
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