As iPhone developers, you have to test your software on every OS version.  This would be fine if there were a reasonably simple way to switch between iPhone OS versions.  As it turns out, there isn’t.  Upgrading is easy — but downgrading isn’t allowed by default within iTunes.

There is, however, a way to do it.  I figured it out the hard way, so I’m posting these instructions to help anyone else who might be in the same situation.  Partial credit is due to other tutorials that I borrowed information from.

If you’re getting iTunes Error 1600 and iTunes Error 20, this tutorial should help.

Disclaimers: Don’t do this with your personal phone, because you have to remove iTunes and completely reset the phone.  Restoring everything later is probably possible via backup, but make sure there’s nothing important on the phone before proceeding.  I don’t think this works on the 3GS phone.  But don’t even try it.

Downgrading from iPhone OS 3.0 to 2.2.1

1. Completely Uninstall iTunes 8.2 AND Apple Mobile Device Support
2. Install iTunes 7.7 (find it on an old version website).
3. Download the 2.2.1 (or 2.2) ipsw file for your phone.
4. Launch iTunes, connect to USB, and enter DFU mode (see below).
5. iTunes will mention restore mode.  Click OK and then Shift-click “Restore”
6. Choose the ipsw file you downloaded.  Wait for restore.
7. If this completes successfully, congratulations!  You’re done!  If you get Error 1013 (as I did), ignore and continue.
8. Hold the Power and Home button for 15 seconds, then press Power for 2 seconds to reset your phone.
9. You should now have the “Emergency Call” screen.  If your phone has service, it should activate itself.
10. If you’ve switched phones (to a 3GS for instance), you will need to either purchase phone service for it, or activate it via jailbreak.
11. Once activated, you’re ready to start testing!

Let us know if these instructions work for you!

We had a great time this summer as one of the 10 companies that participated in TechStars. I took a lot of photos, and I finally got around to uploading them to the internets. However, these photos are a skewed view of TechStars because I mostly took photos when we weren’t working. So consider the following photos mostly a story of the 5 to 10% of the time we were goofing off.

Our team from the summer. Left to right: Gandhi, Jeff, Vikas, and Shun. This is actually one of Andrew Hyde‘s photos.

Soul Patch Concert

Unwinding at the St. Julien after the first demo day:

TravelFli showing off their EntrepreneurWear t-shirts, a counterpoint to VCWear.

Foodzie with Howard Diamond, one of the TechStars mentors.

Rock Band! Andrew Hyde is rocking out on the drums as usual.

Our official company book, it goes everywhere with us.

Andrew Hyde and Jeremy Tanner hanging out at the Bunker.

Jeff and I on stage at Boulder New Tech Meetup.

Hungry entrepreneurs feasting on Foodzie food ferociously. Alliteration anyone?

Tailgating in the parking lot before a Live/ Blues Traveller concert at Red Rocks with Ignighter.

Team Ignighter vs a hybrid Occipital / TravelFli team in a beer pong tournament at our house on the Hill in Boulder. This tournament was where BHARD was born.

Samantha Murphy, the Highway Girl, being amazing on stage at the Laughing Goat.

Our sublet for the house on the Hill ended 2 weeks before the final demo day, and luckily Foodzie let us crash at their place. Gandhi and I slept on the living room floor. Here is Gandhi curled up on the living room floor.

Shun and Jeff slept in the extra bedroom.

Practicing for demo day:

Foodzie’s awesome and adorable dog, Bently, who woke us up every morning in the living room.

The team practicing for demo day:

TravelFli prepping for demo day:

Foodzie with Brett Jackson.

A pizza box with a phrase very similar to “BuyPlayWin“.

Finally it’s Demo Day! Here’s Jeff on the way to the theater.

Team Ignighter looking sharp. Adam, the one in the futuristic coat, is saying “this guy knows what I’m talking about!”

TravelFli dressed appropriately.

Jeff presenting.

And then to unwind! Here we are at the Kitchen Upstairs.

Molly eating an entire ramakin of ketchup (thanks for teaching us that word Austin!).

Austin asking “who wants to go to Houston?”

Nerding it up at the Bunker by playing StarCraft with Devver and BuyPlayWin.

Occipital Founders vs Interns ping pong battle.

David and Jill Cohen invited us all to their beautiful house for an end of TechStars party.

David Cohen, executive director of TechStars, manning the grill. He’s saying “eat more, faster!”

T-Shirts from some of the companies.

Joe “two beer” McVicker from App-X talking to Tom Keller of IntenseDebate.

Ben from Devver saying to his girlfriend, “I’ve got something really important to tell you, my real job is as a backup Britney Spears dancer.”

And here is Ben showing off those dancing skills in the Cohens’ backyard.

And finally, the team at the end of TechStars having a well earned drink. It took me the entire summer to get Shun and Gandhi to drink with us. We miss you guys!

Speaking of the slackers… Andrew recently unveiled the TechStars lipdub, which is an accurate portrayal of how we spent our days this summer. And by days, I mean one single hour. The beer is all product placement, that’s how TechStars stays afloat. It’s true. By true, I mean false.

TechStars LipDub from Andrew on Vimeo.