iPhone 5 Release Date: Apple Confirms Siri's Exclusivity to iPhone 4S

Apple confirmed Siri would remain an exclusive iPhone 4S feature.

The company stated the news in a recent email sent to developer Michael Steeber.

“Engineering has provided the following response regarding this issue: Siri only works on iPhone 4S and currently have no plans to support older devices,” said Apple in the email.

“Apple briefly let staff get a test build of iOS 5 with Siri on the older model that was pulled once the trial was done. The dry run supposedly went 'really well',” said sources to technology website Jailbreak Nation.

Several developers released their progress with porting Siri onto several devices, including the iPhone 4, the iPad and the iPod Touch.

Developer Chpwn recently reported on his blog that he and Steve Troughton-Smith are the only two who have successfully ported Siri to the iPhone 4 and connected to Apple's servers. Chpwn noted that releasing Siri, as a downloadable port, is illegal due to Apple’s copyright of its source code.

Several insiders said there is no reason why the iPhone 4 cannot run Siri, as its A4 processor has shown it is capable of powering the program.

Apple has said Siri is meant to be exclusive to the recently released iPhone 4S.

Technology website Electronista suggested Apple established this exclusivity to promote 4S sales and to manage the load on its servers.

Even with the 4S powering the artificial intelligence system, the company recently experienced a Siri outage for several hours, Electronista noted.

Apple admitted on its website the currently released version of Siri is still a beta being developed.

Insiders propose once Siri is further developed, it may be available to the iPhone 4 and other Apple devices.

They also noted the microphones on the iPad and iPod Touch are not powerful enough to properly execute Siri.