iphone OS 3.1.3 requires snow leopard upgrade

itunes asked me to u开发者_如何学Cpgrade my iphone's OS to 3.1.3, so I complied naively.

then xcode told me that the latest iphone OS version it could support was 3.1.2. So I went to download a new version from https://developer.apple.com/iphone/index.action#downloads, xcode 3.2.2 with iphone SDK.

but when i went to install that, i was told I needed snow leopard 10.6.2 or later. so I'm just making sure that I am not misinterpreting anything when I say that, given that it is impossible to downgrade iphone OS versions without jailbreaking, I need to install a new version of the OS just so I can resume testing apps on my iphone?

given that it is impossible to downgrade iphone OS versions without jailbreaking

I'm not sure that's correct. I've done it before on ipods. If you go to ~/Library/iTunes, there's a few folders in there. Look through the folders for files with an "ipsw" file extension. These are the software upgrades. When you perform an upgrade, the upgrade file is saved here. So find the one you want to "downgrade" to. If you can't find it you may be able to google for it. In any case find the appropriate file. Then in iTunes if you option-click "Check for Update" it asks you to choose the file you want to use to perform the update instead of running the update check normally... so just select the ipsw file. That should "downgrade" you... I think. As I mentioned I did it a few years ago on an ipod.