Ah, the old E220. I bought this from 3 mobile (Ireland) for the princely sum of €120 (plus a 10GB data contract of €20 per month for 12 months)

Of course, I can now buy a HSDPA phone with a touch screen and GPS for less than that but it made financial sense at the time. Anyway, seeing as I never use this, I thought it would be a safe target for my tinkering. And an unlocked 3G dongle will never go to waste!

Step 1: Research

Google to the rescue! My first stop was a website called, oddly enough, unlocke220.com. Sounds promising right? And it is... to a degree. The webmaster kindly documented how to unlock the dongle and even provided the software necessary. The problem was, the software could only be downloaded if you first downloaded some suspicious toolbar packages. No thanks! To make things worse, the software you can download no longer matches the instructions because it is has been upgraded beyond casual recognition. So how to proceed? Carefully ;)

Step 2: Get the necessary software

First we need the latest firmware installer package.
    ftp://ftp.oriunde.net/vmc/Firmware%20Upgrades/Huawei_E220-USB-SmartModem/E220Update_11.117.09.04.00.B268/E220Update_11.117.09.04.00.B268.exe
Second we need PSAS.
    http://psas.revskills.de/
Third we need a hex editor.
    http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm
Fourth we need a tool to enter the unlock code.
    http://depositfiles.com/en/files/1248euw0u

Step 3: Follow the guide

Although these guides are common, I rewrote this because a) they didn't work for me and b) they don't work with PSAS

Remove the sim from the dongle
Insert the dongle
If the driver is not installed, install it
Run the firmware installer package, found above. DO NOT LET THE FIRMWARE INSTALLATION COMPLETE
When you get to the screen showing you the old version of the firmware and the new version, exit the installer
Run PSAS
Run "Hardware Forensics > Use Mobile Ports"
Select the "DIAG" tab
Push "send". You should see some text appear with a pair of dates in it
In the "end" box type 00001000
From the list with "Save memory to file" select "Read EFS"
Push "Let's go". Save the file anywhere you like (I recommend e220.bin on the desktop)
Open XVI32. Open the file you just created.
You should see a lot of hex. There should be a large block of empty data near the start. If not, something has gone wrong.
Search for the hex string "53642C00"
When you find it, look in the right hand pane. Just after it there should be eight numbers in a row. Copy them down
Run the sim unlock tool. Enter the eight numbers

Voilà!

That should do it.

Step 4: Shower me with praise and riches

Please? Eh, worth a try. 

Image file is licensed under the Creative Commons Attribution 3.0 Unported license.