How to Modify an OS X install disc to work on other computers.

One of the problems people have with older macs is finding operating system discs. Its

common for somebody to buy these gray versions from places like eBay thinking they will work

on their Mac only to try them out and get a message like this.

But I wanted to show you a way to bypass this problem. You may need to use a different mac.

Put in the disc you have and then open the disc utility like this. Then select the DVD

drive and click NEW IMAGE. Go ahead and save it to your desktop. Also be sure to pick READ/WRITE

for the image formt. This will copy the disk to your desktop, and expect it to take a while.

When it is finished, go ahead and eject the real DVD from the drive.

OK, now we need to find out your MACHINE ID. The easiest way to do this is to go to the

utilities folder and open a terminal. Type in SYSCTL HW.MODEL. In my case the model is

Macmini1,1. You may want to write this down if yours is different.

OK so go ahead and open the image and look through the files. Scroll down and find the

SYSTEM folder, then go into INSTALLATION, then PACKAGES, then scroll down and find OSINSTALL.

What you'll need to do is RIGHT-CLICK or you can also do a CONTROL-CLICK where you hold

down control and click your mouse. Then select SHOW PACKAGE CONTENTS. Next go into the CONTENTS

folder and find OSINSTALL. You'll need to right-click this and select OPEN-WITH, OTHER,

then locate TEXTEDIT.

Now, what you are looking at here where it says BAD MACHINES are computers which are

specifically NOT allowed. Make sure your model is not listed here. If it is, delete yours

from the list. Next scroll all the way to the bottom and find Supported Machines. You'll

need to add your machine in there. In this case I'll put Macmini1,1. You may need to

unlock the file if it asks. You may want to look through the file and see any other lists

of machines and make sure to add yours to the list. When you are all done, save the

file. Next, dump the mounted image in the trash, don't worry this won't delete anything.

OK next find a suitable dual-layer blank DVD and insert it. Now find the image on the desktop

and right click and select open with disk utility. Once it opens, select the image here,

then click burn. Once it is done burning, you have successfully created a replacement

installer disc that should work with your system. Now you can insert it into the machine

you want to use it on, and it should work just fine.

OK, So I think I should point out one important aspect of this little trick I've shown you.

And that is, this is not going to help you run an operating system on your computer that

is flat out incompatible. It's only really going to help you in two scenarios. The first

scenario is where you've bought a disc that's simply been coded for a different machine.

For example you have a Mac Mini but you got a restore disc for an iMac. And Apple for

some reason or another made those discs so that you couldn't put them on one or the other

even though there is really no technical reason why they won't work. The second scenario where

this trick would be useful is there are some computers where the operating system is actually

known to be compatible but for some reason Apple didn't want to support it, and so they

locked out certain older computers. But, you know, if you see on the internet people saying,

"well this operating system, even though it isn't officially supported, can be made to

work," Well then that is another scenario where this little trick will help you.

And so the reason I had to do this little trick was because I wanted to answer a common

question I get asked, which is about OS 10.4 Tiger. People want to know is it truly obsolete

or is it still useful today? Well, I decided I would try to make a video about that. First

I had to find a copy of Tiger that would work on an Intel machine because I wanted to run

it on this Intel Mac Mini. And I couldn't find one. And so that's why I had to do the

trick. So yeah I'll be showing you that video probably here in just a few days. And in the

meantime, leave me some comments and tell me what you think about this trick!