The TouchPad: George Gerpheide invented the capacitance-based touchpad mouse in 1988, but the technology didn't appear on a laptop until 1994, with Apple's PowerBook 500 series. Apple called its version the trackpad, and other manufacturers soon developed copycat input devices. The touchpad helped laptops become easier to use and more compact.
The PowerBook 500 series consisted of four models: the 520 (which PC World named as one of the ten most important laptops of all time back in 2007), the 520c, the 540, and the 540c. The basic specs for the PowerBook 500 series included 4MB of RAM with capacity for up to 36MB, a 25MHz processor, and a 9.5-inch grayscale display. Models in the PowerBook 500 series also sported up to 320MB of hard drive space--impressive for the time, but less than one-twelfth the storage capacity of Apple's smallest iPod today.
Photo credit: PowerBook 500 Danamania
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