Query: Original 360 Alpha dev kits used what existing system's hardware?
Context: On August 12, 2003, ATI signed on to produce the graphic processing unit for the new console, a deal which was publicly announced two days later. Before the launch of the Xbox 360, several Alpha development kits were spotted using Apple's Power Mac G5 hardware. This was because the system's PowerPC 970 processor running the same PowerPC architecture that the Xbox 360 would eventually run under IBM's Xenon processor.