I tried that, but the resolution won't show up. Following instructions from #1, I:
1. Found my DisplayProductID and DisplayVendorID, 0x1343 and 0xdae:
users-Air:~ user$ ioreg -lw0 | grep IODisplayPrefsKey
| | | | | "IODisplayPrefsKey" = "IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@0/display0/AppleBacklightDisplay-dae-1343"
I am only using the laptop's internal screen, which is detected correctly as far as I can tell. About this Mac/Displays says:
Built-in Retina Display, 12.9-inch (1920 x 1080), Intel HD Graphics 4000 1024MB. Also I have attached Clover's config.plist just in case.
2. Generated a plist using
https://comsysto.github.io/Display-...or-with-HiDPI-Support-For-Scaled-Resolutions/ with my native resolution 1920x1080, the HiDPI resolution I want (1600x900), and another double that (3200x1800):
users-Air:~ user$ cat /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-dae/DisplayProductID-1343
<?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>DisplayProductName</key>
<string>UX31A Screen</string>
<key>DisplayProductID</key>
<integer>4931</integer>
<key>DisplayVendorID</key>
<integer>3502</integer>
<key>scale-resolutions</key>
<array>
<data>AAAHgAAABDg=</data>
<data>AAAGQAAAA4Q=</data>
<data>AAAMgAAABwg=</data>
</array>
</dict>
</plist>
3. Saved it to /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-dae/DisplayProductID-1343:
users-MacBook-Air:~ user$ ls -la /System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-dae
total 8
drwxr-xr-x 3 user wheel 102 7 Jul 05:53 .
drwxr-xr-x 24 root wheel 816 4 Jul 23:00 ..
-rw-r--r-- 1 root wheel 505 7 Jul 05:53 DisplayProductID-1343
4. Rebooted.
But the resolution won't show up when I option-click on System Prefs/Display/Scaled, nor in RDM, nor in the Current Resolutions tab in SwitchResX. EDIT: If I look for it in the Custom Resolutions tab, I see:
1600x900, Type Scaled, Status System Only
1920x1080, Type Scaled, Status System Only - Invalid
3200x1800, Type Scaled, Status System Only - Invalid
However, I can tell OS X is reading the plist because the name of the display profile at the top of the list in System Prefs/Display/Color has changed to "UX31A Display"