Apparently it’s not commonly known, but you actually can run good ole OS X Mavericks on a Mac mini (Late 2014) which was released with Yosemite already

Requires a few tricks, but nothing complex

If there’s any demand, I can release a tutorial + software to simplify the process

@nyan_satan Which KEXT did you patch, and how? I'm interested in running Mountain Lion / Mavericks on my 2014 Mac mini.

@headflowers34767 long story short, I added missing connector/framebuffer configuration in AppleIntelFramebufferAzul kext

That’s for Mavericks. Mountain Lion is the same story as Mavericks, but requires a few more tricks

I will create a tool that automates the most of the process, and also write an article with explanations what it does and why

@nyan_satan Any chance for publishing the tool? (if it's too much effort, a rough gist/pastebin dump outlining the steps/binary patches would also be appreciated)

@headflowers34767 I gotta actually write it first. Currently I’m working on audio

Long story short, I did the following:

0) Compatibility checks

Just add “-no_compat_checks” boot-arg (not exactly sure about spelling, but it’s a known one in Hackintosh community). And then boot.efi & friends will be happy!

1) Installation

I do it from terminal inside Mavericks installer. I don’t remember exact command, but that wasn’t hard to guess

The annoying part was compatibility checks in package scripts. They are written in JS and thus are not hard to patch, but repackaging all that…

For the upcoming tool I plan to skip the script altogether via dyld interposing and/or Objective-C method swizzling

2) GPU acceleration

AppleIntelFramebufferAzul kext in Mavericks lacks connector config for this Mac mini, but you can steal it from Yosemite and hardcode into Mavericks. I don’t remember all the details, but IIRC it’s a simple data-only patch you can do via a hex-editor alone. Don’t forget to fix code signature and rebuild kernel cache!

Mountain Lion seems to use a bit different format to encode that data by the way

In the tool I plan to use Lilu kext (Hackintosh thingie) to apply that patch dynamically

3) Audio

It seems to be a stupid problem similar to the one with GPU. Old kext doesn’t have a proper config for the newer Mac. Should be not hard to fix

4) Wi-Fi, Bluetooth and SD card reader seem to work fine out-of-the-box

@nyan_satan Thanks so much, giving this a shot!!