Force default bootup resolution on headless machine?

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Level 2

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Force default bootup resolution on headless machine?

Is there any way (via CLI, editing pref files, ANTHING!) to set a machine's default bootup resolution to something specific?

Basically, when there is no monitor attached to the mini upon boot, it defaults to 640x480, so when I try to ARD into it on a 30" monitor, it's just horrid (and of course doens't give me the option in sys prefs to change it because it's not detecting a monitor and therefore no "available" resolutions to choose from).

So, can you force the mac to boot at a specified resolution (much higher than the lowest found default) every time?

Thanks!

Mac OS X (10.6.6)

Posted on Feb 10, 2011 2:56 PM

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Answer 1

Best reply

Community User

Oct 30, 2017 12:35 PM in response to M3dici

It doesn't work for me: on macOS High Sierra via

sudo nano Library/Preferences/SystemConfiguration/com.apple.Boot.plist

(i hate vim) when i try to save the file, it returns Operation not permitted

Also using su it gave me the same error.

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Answer 2

M3dici

Level 1

0 points

Feb 14, 2011 5:42 PM in response to jinniferb

Hi jinniferb

There is no guarantee whatsoever that this will work, but you could try the following:

Go to directory /Library/Preferences/SystemConfiguration/ and create a backup of com.apple.Boot.plist, basically just copy the file and paste it as com.apple.Boot.plist.bak.

Edit /Library/Preferences/SystemConfiguration/com.apple.Boot.plist through vim in the terminal (as sudo/root) or through a text editor.

Add the following:

<key>Graphics Mode</key>
<string>1280x1024x32</string>

Replace the resolution with your own. An example file might look like this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel Flags</key>
<string></string>
<key>Graphics Mode</key>
<string>1280x1024x32</string>
</dict>
</plist>

Save the file, make sure its saved as a .plist.

Reboot the machine.

If you have no luck then SSH into the machine and rename the com.apple.Boot.plist.bak to com.apple.Boot.plist then reboot again.

Again no guarantees whatsoever that this will work, and do so at your own discretion.

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