Where can I get previous versions of the iOS disk image?

Question

I have just become a member of the iOS Developer Program, and I am reading the user guide for the iOS Developer Program. It says:

• Download the iOS disk image (.dmg) from the iOS Dev Center for your Apple device.

Well, in my Xcode Organizer I see two versions: 4.2.1 (8C148) and 4.3.2 (8H7). Suppose I want to test my application on a previous version of iOS, say 4.0 or 3.x. Where can I find / download iOS Disk Image (firmware), as the document says?

Thanks.

Answer 1

do you mean IPSW firmware? Google has good results:

http://www.iphoneheat.com/2009/03/download-iphone-firmware-files-all-at-one-place/

Answer 2

Apple has set itself the task of double-checking firmware on iOS devices. Once you upgrade to 4.2.x (I think), you may not be able to return. However, you can go here for older firmware .

Answer 3

Here you can find additional information: Testing several versions of iOS in Simulator