Looks like a new iPad isn't the only unannounced iDevice referenced in the code of the new iOS 5.1 beta. Last night Apple released the iOS 5.1 beta to registered developers and, after spending some time digging through the code of the new software, a reference to a new model of iPhone has been discovered. The new handset is identified as "iPhone 5,1," a name that suggests that it may feature some major internal changes from the iPhone 4S (aka iPhone 4,1). An example of a device with only minor changes from its predecessor is the iPhone 3G (iPhone 1,2), which added 3G and GPS to the original iPhone (iPhone 1,1) internals but retained the first handset's processing power.

There's not much we can take away from this news save for the fact that Apple is hard at work on a new iPhone (shocker!), but it's still kind of exciting for iOS-obsessed folk to finally spot the first reference to upcoming handset in Apple's own code. Now that the iPhone 5,1 has been dug up, expect the iPhone 5 rumor mill to kick into high gear any time now.

Via Today's iPhone, 9to5Mac