In what could be an apt reminder of the stages of technological advancement and how far the concept smartphones has evolved, an early iPhone prototype image has hit the Web. Images of the in-house version show a 5x7 inch screen and a number of ports including Ethernet, USB and serial port.

The 2005 prototype has been released by Ars Technica, revealing that the iPhone was as large as an iPad Mini two years before its debut. The in-house version of the device has reportedly been leaked by a former Apple employee who worked on various Apple hardware projects in the early 2000s, Ars Technica states.

The device notably had a number of ports that we normally see in computers, including USB ports, an Ethernet port and even a serial port. Although Apple did not intend to include all these in the handset, the source revealed that these were added on to the prototype to make it easier to work on the device.

The large size of the device is another interesting fact about the handset. It measured five inches wide, seven inches tall and nearly two inches thick. It appears quite large now, but according to the source, it was really impressive to see basically a version of OS X running on the device then.

The processor shown in the prototype is not much different from the final one used in 2007. The ARM chip appeared to be a variant of the Samsung S3C2410 which, according to Ars writer Andrew Cunningham, "is a distant relative of the chip the first iPhone ended up using, just older and slower." The chip in the early prototype image was clocked at 200-233MHz while the first iPhone used a 620MHz chip under-clocked to 412Mhz.

"This chip is also an ARM9 chip, while the original iPhone eventually ended up using an ARM11 chip, but obviously Apple intended to use Samsung-manufactured ARM chips even this far back," Cunningham said.

Apple has released six variants of its flagship smartphone so far and the next in the series, unofficially dubbed iPhone 5S/iPhone 6, is rumored to come sometime between April-June 2013. Many have speculated that the Cupertino tech titan may release three variants of iPhone in 2013, including a new version of the iPhone 5, an iPhone 6 and another an entry-level affordable phone. The latest rumor is that Apple may use Qualcomm's Snapdragon system on a chip (SoC) in its rumored low-cost phone.