Carbon - Intel Mac mini vs M1/M1x Mac mini

[dominicperry]

These guys have an even more comprehensive set of instructions. I will agree that this is not for the feint-hearted and I'm not clear on what you're left with if it doesn't work - it's very possible to brick a machine if a firmware change screws up...

https://mrmacintosh.com/category/downgrade-macos/

[Ben Jenssen]

Originally Posted by dominicperry

You may have to downgrade the firmware first, as described here.

https://support.apple.com/en-gb/guid...dd5f3c75ad/mac

Unfortunately I don't have a suitable Mac here to test with. It has previously always been possible to downgrade the OS to a version which existed when the machine model was released, even if the particular one you bought came with something later. Apple seems to be making this more and more difficult.
Generally I wouldn't advise fiddling about to this degree, but Monterey and PT are really not friends at all. So I think it's worth persisting with trying this, regardless of what Sweetwater says.

That link doesn't work.
Look, I'm pretty shure it's like this:
Since Big Sur, MacOS recovery partition is "untouchable". It can't be manipulated, and if it is damaged in any way, your mac is a brick. Apple must place a new drive in it. If it's OK, without a internet connection, it will install the original system from recovery partition. If online, it will install the latest OS. And you can no longer just 'create a USB installer'. I can see the benefits from this change, and why they did it.


I've been imaging, restoring, installing and manipulating mac OS'es since System Seven, so I can also see that we lose some freedom with this. But this is how it is.

[dominicperry]

Originally Posted by Ben Jenssen

That link doesn't work.
Look, I'm pretty shure it's like this:
Since Big Sur, MacOS recovery partition is "untouchable". It can't be manipulated, and if it is damaged in any way, your mac is a brick. Apple must place a new drive in it. If it's OK, without a internet connection, it will install the original system from recovery partition. If online, it will install the latest OS. And you can no longer just 'create a USB installer'. I can see the benefits from this change, and why they did it.


I've been imaging, restoring, installing and manipulating mac OS'es since System Seven, so I can also see that we lose some freedom with this. But this is how it is.

I've fixed the link.
I'm not going to argue, as I can't prove the point either way. I don't think you are correct, however, and if it was me, I'd try to downgrade it, given that in the UK you can return an Apple purchase, free-of-charge, for 14 days.

YMMV, as they say.

Dominic

[JFreak]

Originally Posted by Ben Jenssen

5 minute search and I find this:
Sweetwater Knowledge Base

Originally shipped means if that MODEL originally shipped with Monterey you cannot use Big Sur, but if that MODEL has shipped on Big Sur, even if yours shipped with Monterey, then downgrade is possible


Sent from my iPhone using Tapatalk

[Ben Jenssen]

Originally Posted by JFreak

Originally shipped means if that MODEL originally shipped with Monterey you cannot use Big Sur, but if that MODEL has shipped on Big Sur, even if yours shipped with Monterey, then downgrade is possible

Ah. I see.
But you would have to get apple to change the drive, I think. Because that Monterey recovery partition is 'untouchable'. No?

[JFreak]

Originally Posted by Ben Jenssen

Ah. I see.
But you would have to get apple to change the drive, I think. Because that Monterey recovery partition is 'untouchable'. No?

No, but if you touch it you really need to know what you are doing. With the security chips in place, clean installs have become PITA. There are benefits too, but simple thing as downgrading is not so simple anymore. I would only do it on friday evening with whole weekend avialable to spare. Did a fresh clean erase everything install to my M1 mac mini and it is not easy.

Read all tutorials and then more. Assume you know nothing if you do it first time, even if you had done millions of clean installs without security chips.

[Ben Jenssen]

Originally Posted by JFreak

No, but if you touch it you really need to know what you are doing. With the security chips in place, clean installs have become PITA. There are benefits too, but simple thing as downgrading is not so simple anymore. I would only do it on friday evening with whole weekend avialable to spare. Did a fresh clean erase everything install to my M1 mac mini and it is not easy.

Read all tutorials and then more. Assume you know nothing if you do it first time, even if you had done millions of clean installs without security chips.

So… you know it's doable… because you've done it?

[JFreak]

Yes. Wasn't a walk in a park though. Maybe because I did it first time. If you are not familiar with UNIX command prompt you can forget it.

[Ben Jenssen]

Originally Posted by JFreak

Yes. Wasn't a walk in a park though. Maybe because I did it first time. If you are not familiar with UNIX command prompt you can forget it.

So it's the model that determines what OS version can be installed. Not the version it comes with, and the version of recovery partition, like I said. But we agree that rolling back is seriously limited.

Anecdote: My closest encounter with this, and part of the reason I decided to stay w/Catalina on Intel, was two weeks with a M1 Mini earlier this year, and Carbon Copy Cloner could no longer create bootable backups because of this change with Big Sur. They might have solved that now, or found a workaround.

[JFreak]

CCC and DiskWarrior are both a disaster now, and it is these security chips "to blame"