The Ultimate iOS 1 Downgrade Guide

Ever wanted to use the first iOS version ever? If so, then I will show you how to downgrade your iPhone 2G or iPod Touch 1st Generation to iOS 1.x.x!

Disclaimer

Before starting this guide, if you have an iPhone 2G and you are downgrading to iOS 1.0.x, check to make sure your iPhone is able to run it. Check the back of your iPhone for the serial number. In order for this to work, the third number of the serial must be "7" and the next two numbers have to be "48" or lower, or it won't work. (Source)

I am also not responsible if you brick your device trying to do this. Make sure you back up your important data before proceeding, as this will erase EVERYTHING!!

What you need

An iPhone 2G or iPod Touch 1

A REAL PC running Windows XP 32-bit

A 30-pin cable

Your device's IPSW for the build of iOS 1 you want to downgrade to

Installing iTunes

Download iTunes 7.5 from this link and install it. Make sure to uncheck automatically update Apple software, and never update iTunes.

Now, just open iTunes and set it up how you like it.

Downgrading

Go to one of the links below, and download the IPSW for the build of iOS 1 you want to downgrade to. Put it in a place where you will remember it!

Once you have your IPSW file, connect your device to your computer. Now, we need to go into DFU mode. Follow the steps below.

Press and hold power and home for 10 seconds

After 10 seconds, let go of power, but keep holding home until your device connects to the computer.

Now, hold shift and click restore. Select the IPSW you downloaded earlier. Now, it will restore the device.

If you get an error other than 1015, try again, and if it still doesn't work, blow in your USB port and both ends of your cable, or even switch the USB port and/or cable and try again.

If you get error 1015, just download ZiPhone from this link, run the exe, which will extract it to your desktop, open ZiPhoneGUI.exe, click show advanced features, click normal mode, and when it's done, close ZiPhone.

Now, the device will boot to a screen that asks you to connect to iTunes. If you have a SIM card in your iPhone 2G (if it says No Service, there is a SIM), or your device is an iPod Touch 1, just go to the device in iTunes, and set it up how you like. Otherwise, the jailbreak will help us get into our device.

Jailbreaking

Download iLiberty+ from this link, extract the ZIP file, run the setup, and install it. Now, open iLiberty+ with your device connected. If you can't activate normally on the iPhone 2G, check activate. Otherwise, check jailbreak. Don't bother with other options, as they are useless now.

Now, just click go for it. Now, disconnect your device from the PC, reconnect it, and click OK. Your device will now be jailbroken. If iTunes gives you any messages, close them. You should see some white text scrolling, and after that, if you selected activate, a screen with a blue bar at the top will show. Your device is now jailbroken, but we are not done!

Installing Apps

Normally, you can't install apps to iOS 1 since there is no App Store. But now that your device is jailbroken, you can install apps using PXL files! We will use iBrickr to do this. (no, it doesn't brick your device, it is a file management program for your iDevice)

Download iBrickr from this link, extract the ZIP file, and open it. I would recommend right clicking ibrickr.exe, hovering over send to, and clicking desktop to put a shortcut on your desktop so that you can always find it.

Now, click applications, and click install PXL. When it asks you to restart, hold the power button for about 5 seconds, slide the power off slider, and once your device is off, hold the power button for 3 seconds to turn it back on. Once your device is on and it connects, click continue on iBrickr, and when it prompts you, restart again using the previous instructions given. Once it's on and it connects, click check for PXL. If you installed it correctly, it should now bring up a menu to install apps.

Now since the browse applications button on iBrickr doesn't work anymore, go to one of the links below to download apps.

Save these files to a place where you will remember!

Once you have the apps that you want, go back to iBrickr, click install from PXL file, and select the PXL file you want to install. Now, your device will respring, and the app will be installed. If you choose to install more, click back to app list, and install everything you want.

If you install NES, iBrickr will have a button to upload NES roms. If you want to add ROMs manually, put them in "/var/root/Media/ROMs/NES", as this is where the emulator looks for ROMs.

Known Issues with Certain Apps

I have a separate page for this. You can find it here

THE END

I hope this guide helped you! Have fun with your newly jailbroken and downgraded iOS 1 device! :D

If you have any issues, send me an email regarding your problem at adavison512@gmail.com