PRAM replaced with coin battery.

The Power Mac G5 marked Apple’s dramatic break from the long-running G3 and G4 tower era, introducing the big aluminum enclosure that set the look of Apple’s professional desktops for years to come. Announced in 2003 as the first 64-bit PowerPC Mac, it also represented the peak of Apple’s pre-Intel workstation ambitions, aimed squarely at high-end creative and technical users before the company shifted to Intel just a few years later.

• EveryMac