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macrumors member
Original poster
Apr 10, 2008
Two questions related to BIOS emulation:
  1. I have a mid 2010 model iMac, does it support BIOS emulation? How can I find out?
  2. Assuming I completely format my hard disk, how do I enable BIOS emulation, is it enough to have a hard disk with MBR partition table?
Rationale / Background:

I would like to dual boot Windows 8.1 and Ubuntu 14.04 on my iMac. I have no need for OSX (I have an external emergency USB HDD on which I have OSX 10.8 installed in case I ever need it).

Since I do not intend to use OSX on my iMac, it would not be recommended to use EFI to boot either Windows 8.1 and Ubuntu 14.04 because as far as I know, at least on the mid 2010 model iMac, Apple has implemented their own brew of EFI based on 1.x version and that apparently requires the "bless" feature in OSX for smooth operation and avoiding problems. So I would like to install and boot both Windows 8.1 and Ubuntu 14.04 in BIOS emulation mode.


macrumors G3
Sep 21, 2010
What's the problem with EFI needing bless? I can use Windows installed EFI with no OS X present at all and it works fine.

In any case, to answer your questions:

1. Yes.
2. You don't need to enable anything. The Mac will use automatically use BIOS emulation if you boot up from a BIOS-bootable disk. For Windows, don't choose the EFI installation at boot time. I don't know about Linux, but looking at Linux-on-Mac guides, they seem to be mostly for installing Linux in BIOS mode--if they are for installing Linux in EFI mode, they seem to say so.
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