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I found this file kicking around on my hard drive, and thought I should at least put it out there.

This guide outlines the steps an individual must take to get FreeDOS installed and running on an Intel-based Macintosh. An interesting thing about this process is that it seems that some people believe this isn't possible;

http://os.newsforge.com/os/06/09/12/1628227.shtml?tid=16

Mac users will need to run FreeDOS inside an emulator "for the foreseeable future" due to the lack of support for the Extensible Firmware Interface, which Intel-based Macs use to boot, and which Hall says is not on the list of future features right now.

So now we're out to prove them wrong!

Before you start

Before starting, make sure that you have at least a few gigabytes of free space on your hard drive. While FreeDOS is perfectly happy with less than half a gigabyte, you'll have a much lower chance of ruining your data if you have lots of free space.

You'll need to download FreeDOS, so point your browser to http://www.freedos.org/freedos/files/, pick an iso image and a mirror, and start downloading. To burn the resulting iso image, follow these steps:

1. Locate Disk Utility, which resides in /Applications/Utilities. Start it up.


2. Insert a blank CD into the drive. If a window pops up asking what program you would like to open it, choose "Disk Utility" and hit OK. A blank CD should show up in Disk Utility's left pane.


3. Choose File->Open Disk Image... from Disk Utility, and choose the iso file that you downloaded.


4. The iso image should also appear in the left pane as well. Select it, and hit the "Burn" button from the toolbar. Hit the "Burn" button to start the burn process.

Setting up the partitions

Now you need to shrink your existing OS X partition to make room for FreeDOS. Open up Terminal (/Applications/Utilities). First, you will want to find out your disk partition scheme, so enter the following:

diskutil list

This is what should get printed out:

/dev/disk0
   #:                   type name               size      identifier
   0:  GUID_partition_scheme                    *55.9 GB  disk0
   1:                    EFI                    200.0 MB  disk0s1
   2:              Apple_HFS                    55.0 GB   disk0s2

There's two important things here. The first is the size of Apple_HFS, in this case it's 55 gigabytes. You need to decide how much room you want to allot to FreeDOS. 1 gigabyte is more than enough, so you want to shrink the Apple_HFS partition to 54 gigabytes. Get it? The other important thing is what is to the far right of Apple_HFS, in this case disk0s2. This is the device name of your OS X partition, and you will need this in your next command. But first, quit any open applications. You don't want to risk trashing your partition, so the only application that should be open is the Terminal. If you absolutely need your web browser open to read this, it's recommended to copy+paste the command into the Terminal, but don't hit enter until you've quit your web browser. Now that you're ready, type this:

diskutil resizeVolume disk0s2 54G "MS-DOS FAT32" freedos 1G

disk0s2 refers to the device name of your OS X partition; if yours is different, replace it with the correct one. 54 is the new size of the OS X partition, G refers to gigabytes (other units include M for megabytes and B for bytes). Finally, "MS-DOS FAT32" means that you want a Windows partition, freedos is the name that you want to give the volume, and 1G means you want to use the space left over from resizing the OS X partition for the FAT32 partition (1 gigabyte). The output of the previous command should look something like the following:

Started resizing on disk disk0s2 Untitled

Verifying

Resizing Volume

Adjusting Partitions


   
Finished resizing on disk disk0s2 Untitled

You will need to manually reformat your new partitions.

WARNING: You must now reboot!

Naturally, you will want to reboot, so do that right now. Boot back into OS X to make sure everything is alright, then proceed with installing FreeDOS.

Installing FreeDOS

Insert the FreeDOS installation CD you made earlier into your CD drive. Reboot, holding down the 'C' key until you see the FreeDOS startup screen. For some reason the keyboard would lock up when using the arrow keys at certain points, fortunately the defaults were alright for everything. It should at a certain point ask you if you want to format the C: drive. Choose yes. If it says you need to run XFDISK first, do not continue! XFDISK only works with MBR-based partition tables, and you are currently working with a GPT/MBR hybrid partition table. You've probably done something wrong along the way.

Once FreeDOS is finished installing, the rest is easy. Reboot holding down the option key, and you should be given a choice between OS X and Windows. Choose Windows, and you'll be sent to the friendly DOS prompt.