Anal Retentive MAC 1.1.1 to 1.0.2 Downgrade Guide
Before proceeding, as with any guide of this sort, use at your own risk! (Though I believe only minimal risk is involved, with some circumstances, you just never know).
THIS GUIDE IS FOR THOSE WITH THE 1.0.2 'iPhone 1, 1_1.0.2_1C28_Restore.ipsw' FIRMWARE ON THEIR MAC HDD's ALREADY (From a previous 1.0.2 Firmware Restore). DO NOT PERFORM THESE STEPS IF YOU JUST BOUGHT AN IPHONE WITH THE 1.1.1 FIRMWARE AND HAVEN'T TAKEN THE NECESSARY PROVISIONS TO ACQUIRE THE 1.0.2 FIRMWARE IMAGE OR IF YOU DON'T KNOW HOW TO DO THIS.
OK, I have seen many different methods posted on downgrading from 1.1.1 to 1.0.2. While all the credit should rightly go to KMAC, I just wanted to offer to everyone the steps that worked for me. Most of the currently published steps are great for us geeks, however, for those not so comfortable with the currently published steps, this guide is intended to simplify the process by simply being more articulate. I had nothing better to do today, so I thought it would be cool ;-). AGAIN, ALL CREDIT for the awesome work goes to KMAC and crew. Awesome job guys!
The following is intended for current AT&T customers, however, the steps apply to those who have not yet signed up for service.
Note 1: After tinkering for a couple of hours, I can tell you definitively that Apple/KMAC are dead correct about being very sure you follow the Power/Sleep/Wake procedure for approximately 10 seconds. If you do not do this, the downgrade WILL NOT work. This is the true key to performing the downgrade successfully. Again, all the props go to KMAC.
MAC ONLY INSTRUCTIONS:
Please follow all steps carefully and meticulously (Below assumes your iPhone is powered on):
1. If you're in iTunes (7.4.2), safely eject your iPhone. If you're not in iTunes, proceed to step 2.
2. Most of us have our iPhone's connected via the iPhone dock. Remove the male dock end of the USB cable from the dock. Now insert the male dock end directly into the iPhone.
3. If iTunes auto starts when you plug the iPhone USB cable's male dock end directly into the iPhone, again, safely eject your iPhone.
4. At this point, we need to completely remove iTunes from memory. Open Activity Monitor (Applications/Utilities/Activity Monitor), in your OS X dock, right-click your iTunes icon and select 'Quit'. Go into Activity Monitor and select 'Itunes Helper' if it is running and click the RED 'Quit Process' button. When prompted, select 'Force Quit'.
5. Click the iPhone's home button. You should see the big green charging/charged battery.
6. At this point, in tandom, press and hold for 10 seconds (Try to make this exactly, use a stop watch/timer or count using 1/1000) the Power/Sleep/Wake button and the home button.
7. As soon as you hit 10 seconds, release the Power/Sleep/Wake button while continuing to hold the home button. THE SCREEN SHOULD REMAIN TOTALLY BLACK.
8. While still holding the home button down, If iTunes doesn't start automatically, manually open iTunes (Again, while still holding the home button down, time to use the other hand ;) and wait for iTunes to detect the iPhone in 'Restore Mode'. You will know you're doing this right as the screen will STILL BE COMPLETELY BLACK (You SHOULD NOT see the new 1.1.1 iTunes Restore Mode screen on your iPhone).
9. When iTunes recognizes your iPhone in 'Restore Mode', you may release the home button on your iPhone. NOTE: THE SCREEN WILL STILL BE BLACK AND THIS IS NORMAL, THIS IS WHAT YOU WANT.
10. Select OK.
11. Press and hold the Alt/Option key and select 'Restore'.
12. Assuming you have previously downloaded the 1.0.2 firmware via iTunes in the past, when you are prompted for a previous firmware location, navigate from the USER (Your user name) folder to: /Library/iTunes/iPhone Software Updates/iPhone 1, 1_1.0.2_1C28_Restore.ipsw
13. Click Open and the Restore begins.
14. Just like a normal Restore, let the process take its course. At the end you will know you did the process right when you receive an error message coded "xxxx" (Forgot the code, will add it soon).
15. At this point, your iPhone will reboot back to the original 1.0.2 iPhone firmware 'Restore Mode' screen, you will see the yellow triangle. This lets you know that you're iPhone has truly been restored back to 1.0.2.
16. Completely exit out of iTunes (As in step 4, though AppTapp closes it anyway, just humor me here)
16. Download AppTapp installer 3.1 real quick if you don't already have it. If you do, now is the time to run it. Select continue and choose firmware version 1.0.2 from the list and Continue. AppTapp will jailbreak your iPhone and error out at the end telling you the 'Bootstrap' process failed. Ignore this messge and click OK. This process is used to UNBRICK your iPhone. Note: If you want AppTapp installer on your iPhone, you will need to run the app again.
17. If you are a legit AT&T customer, restart iTunes.
18. iTunes will recognize your iPhone and prompt you to activate your iPhone as either a new iPhone or using your existing iPhone AT&T account. Select the existing account. iTunes will continue restoring your iPhone and once again activate it. You can now sync all of your content back to your iPhone.
At this point you will notice the iTunes WiFi music store icon missing from your Springboard. Go to Settings/General/About/. You will notice your iPhone firmware is 1.0.2 (1C28) and your modem baseband firmware is: 04.01.13_G
Configure your WiFi and you're good to go.
I personally have NO desire to unlock my iPhone. If you're like me, at least this will allow you to apply simple hacks while negating the ugly bugs and overhead of 1.1.1. I HAVE NOT TRIED iNdependence 1.1.1 yet, however, since I am back to 1.0.2, there shouldn't be any issues.
Safari is noticably snappier again. If you apply too many graphic mods, be aware that the iPhone only has so much memory for its OS to use. These mods eat memory and cause the OS to run out of memory at times, causing crashes. This is one of the reasons Apple didn't allow for this sort of customizing in the iPhone's menus, this was done for OS and application stability (Even so the iPhone still crashes ;-).