Good news for the owners of the iPhone 4 using turbosim card Gevey SIM , they can can upgrade their devices to iOS 5.  Carrier Unlock of  iOS 5 on iPhone 4 is now possible with Gevey SIM, but for this you must to keep the old modem firmware (baseband).


What is Gevey SIM?
Once long ago, users counted on unlocked iPhone, using software unlock from iPhone Dev-Team as a jailbreak tweak-Ultrasn0w. Unfortunately, the team did not manage to unlock the iPhone 4 with baseband 2.10.04 and 3.10.01. Then the Chinese craftsmen united under the brand Gevey, developed a robust hardware solution. Unlike Ultrasn0w, Gevey SIM offers no software but only hardware unlock. It is based on the so-called turbo-sim that fits in with the main smartphone SIM-card mobile phone operator. Gevey SIM unlock the iPhone 4 supported with firmware modem 01.59.00,  02.10.04, 03.10.01 or  04.10.01 without jailbreaking.

Unlock iOS 5 with Gevey SIM

To go to iOS 5 preserving baseband, you can resort to Redsn0w 0.9.9b5 , which exists now only in a version for Mac. The program allows you to create custom firmware iOS 5 does not change the version of modem iPhone 4.

Before proceeding with the unlock, download official firmware iOS 5 here , iTunes 10.5 here and Redsn0w 0.9.9b5 from here .

Step 1 : Connect the iPhone 4 to your computer and open Redsn0w 0.9.9b5.

Step 2 : Click the Extras, and then the «Custom IPSW» to create a custom firmware iOS 5.

Step 3 : Specify the original file iOS 5, and then continue to build the firmware. Redsn0w begin to create IPSW.

Step 4 : Once click Pwned DFU section of Extras.

Step 5 : Follow the instructions on the screen, put the iPhone 4 in the regime of DFU.

Step 6 : Close the Redsn0w and run iTunes 10.5. The program throws a message saying that your iPhone is in recovery mode.

Step 7 : Hold down the Alt (Mac OS X), click Restore. Specify the firmware iOS 5, was created using Redsn0w 0.9.9b5. Do not mix up the files – the name of the custom firmware begins “NO_BB_”.

If you want to know more on how to Update iPhone 4/3GS to iOS 5 without updating it’s firmware click here.

After restoring the firmware you can use Gevey SIM unlock iOS 5 on the iPhone 4. The demonstration setup for turbo-sim card is shown in the video below:

 

A few minutes ago was released Ultrasn0w 1.2.4 . The updated software provides tweak unlock iOS 5 on the iPhone versions of baseband 04.26.08, 05.11.07, 05.12.01, 05.13.04, 06.15.00 and 01.59.00. If you have one of these modems, you can upgrade to iOS 5 with persistence of unlocking right now.