[GH-ISSUE #306] Retired iMac used as a monitor #240

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opened 2026-05-05 05:29:10 -06:00 by gitea-mirror · 4 comments

gitea-mirror commented

2026-05-05 05:29:10 -06:00

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Originally created by @Sarah-Calumet on GitHub (Oct 13, 2020).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/306

I haven't been able to make this work on my retired 2009 iMac that is now serving as a monitor for a newer Macbook. It's default is max volume, and doesn't seem to be ajustable (except maybe by directly connecting a keyboard).

This is an fyi only in case anyone else is trying to do this. It likely doesn’t affect many people. And is probably a built-in problem with the Apple "target" mode used for this situation.

Originally created by @Sarah-Calumet on GitHub (Oct 13, 2020). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/306 I haven't been able to make this work on my retired 2009 iMac that is now serving as a monitor for a newer Macbook. It's default is max volume, and doesn't seem to be ajustable (except maybe by directly connecting a keyboard). This is an fyi only in case anyone else is trying to do this. It likely doesn’t affect many people. And is probably a built-in problem with the Apple "target" mode used for this situation.

gitea-mirror

2026-05-05 05:29:10 -06:00

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gitea-mirror commented

2026-05-05 05:29:16 -06:00

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@VovS- commented on GitHub (Jan 5, 2021):

Why would you need a third-party app for that? Shouldn't it work natively?

@VovS- commented on GitHub (Jan 5, 2021): Why would you need a third-party app for that? Shouldn't it work natively?

gitea-mirror commented

2026-05-05 05:29:18 -06:00

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@jackjansen commented on GitHub (Feb 12, 2021):

Same problem here: I'm also using an old iMac in Target Display Mode (on a new Mac mini M1, connected via a HDMI->DP adapter and then a DP->MiniDP cable to the iMac).

My current workaround is that I have a second keyboard attached to the iMac, and I can use the volume keys on that.

The iMac is listed in the MonitorControl Preferences->Display with the DDC box off and disabled, so I guess that means Apple haven't implemented DDC (on the iMac in Target Display Mode).

A workaround could be to set the volume on the iMac, using something like

ssh imac.local osascript -e '"set Volume 10"'

but I can't think of a decent way to discover the name of the iMac (the imac.local in the example above).

@jackjansen commented on GitHub (Feb 12, 2021): Same problem here: I'm also using an old iMac in Target Display Mode (on a new Mac mini M1, connected via a HDMI->DP adapter and then a DP->MiniDP cable to the iMac). My current workaround is that I have a second keyboard attached to the iMac, and I can use the volume keys on that. The iMac is listed in the MonitorControl Preferences->Display with the DDC box off and disabled, so I guess that means Apple haven't implemented DDC (on the iMac in Target Display Mode). A workaround could be to set the volume on the iMac, using something like ``` ssh imac.local osascript -e '"set Volume 10"' ``` but I can't think of a decent way to discover the name of the iMac (the `imac.local` in the example above).

gitea-mirror commented

2026-05-05 05:29:21 -06:00

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@waydabber commented on GitHub (Aug 20, 2021):

Well, to be honest it is a very special use case. What you'd need is a networked solution that can control the brightness of the display through the target machine. To be honest I don't think that such a functionality will be added anytime soon. What I'd recommend is to use any command line tool that can change native apple display birghtness like https://github.com/nriley/brightness, create a simple app that listens on a port via network and forwards requests to this nriley's brightness app and then create a some keyboard shortcuts using Hammerspoon on the computer connected to the iMac that forwards requests based on brightness keys. I know it sounds complicated but at most after a few days of tinkering this could be done and would be very satisfying to achieve something like this.

I'll close this issue for now, but let me know if you don't agree with this! Thank you!

@waydabber commented on GitHub (Aug 20, 2021): Well, to be honest it is a very special use case. What you'd need is a networked solution that can control the brightness of the display through the target machine. To be honest I don't think that such a functionality will be added anytime soon. What I'd recommend is to use any command line tool that can change native apple display birghtness like https://github.com/nriley/brightness, create a simple app that listens on a port via network and forwards requests to this nriley's brightness app and then create a some keyboard shortcuts using Hammerspoon on the computer connected to the iMac that forwards requests based on brightness keys. I know it sounds complicated but at most after a few days of tinkering this could be done and would be very satisfying to achieve something like this. I'll close this issue for now, but let me know if you don't agree with this! Thank you!

gitea-mirror commented

2026-05-05 05:29:22 -06:00

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@jackjansen commented on GitHub (Aug 20, 2021):

@waydabber I understand (and agree), my workaround is now that I'm using a set of external speakers.

@jackjansen commented on GitHub (Aug 20, 2021): @waydabber I understand (and agree), my workaround is now that I'm using a set of external speakers.