Apple (NASDAQ:AAPL) is developing its second-generation iPad mini, dubbed the “iPad mini 2,” with a faster A6 chip, but without the highly-anticipated retina display, according to references in an iOS 7 software development kit, or SDK, discovered by a developer.

Technology news website, 9to5Mac, has obtained the iOS 7 SDK from Nick Frey, a developer, who found the details inside a hidden file listing all devices that support iOS 7. The information also has been confirmed with details found within the iOS 7 beta itself.

According to information provided by the developer, Apple is working on three iPad mini 2 models, nicknamed “2,8” , “2,9” and “2,10” following the internal nomenclature for the current iPad mini models -- “2,5,” , “2,6” and iPad “2,7”.

The code names for the iPad mini 2 models are “J75”, “J76” and “J77”, respectively, pointing to one wi-fi only model and two cellular-compatible models, just like the existing iPad mini.

As for the new iPad mini's features, details inside the iOS 7 beta show that the device will have an “s5l8950x” processor, which refers to the same A6 system-on-a-chip found inside the iPhone 5.

If the iPad mini 2 indeed features an A6 chip, it will be a logical upgrade for the device as the current iPad mini is powered by an A5 processor. The A6 chip is expected to offer significant speed improvements, which will help users move around the new iOS 7 operating system faster, load movies quickly, and experience better performance while playing games and running graphics-intensive apps.

However, the details reveal that the new iPad mini models do not include references to the “@2x” code, which denotes retina display-supported artwork. The lack of this particular code, which is included in the iPhone 5 and the iPad 4, led the 9to5Mac report to conclude that the next version of the iPad mini will not feature a retina display.

In addition, the references in the iOS 7 SDK in question also suggest that the iPad mini 2 will feature the same cellular technologies and baseband chip as the current generation iPad mini models, the report said.

Rumors of Apple delaying the release of Retina iPad mini have been around for quite some time now.

Ming-Chi Kuo, an analyst at KGI Securities, said in a research note last week that the much-awaited 7.9-inch Retina iPad mini 2 with an A7 chip could be delayed until March or April next year. Kou also said that the company might release a cheaper non-Retina iPad mini toward the end of this year.