This will install all the third-party patches on your Mac that’ll make Catalina work.
I found that none of the methods mentioned above or elsewhere would allow me to boot my installation media on my macmini2,1 Intel core due 1.8GHz. macmini2,1 installation specials and pain. Helpful kernel flags: rebootp nouveau.modeset0.
Even if you did manage to get a copy via third-party means, code baked into the install will stop it from running on unsupported hardware, but there is a workaround. The problem is that, if you’re running an older unsupported machine, macOS Catalina simply won’t be available to download via the App Store. This means that, essentially, if your kit was released earlier than 2012, you’re out of luck – or are you? While there’s no official way to get macOS Catalina on an older Mac, there’s a techy workaround that’ll get the system running on your older kit – although whether you should or not is a different question altogether.