This 1955 advertisement for the Remington Rand Univac 120 computer shows what looks peculiarly like a gonk power droid. Boasting the ability to compute dozens of calculations per second, a device like this would consume massive amounts of energy!
In the Star Wars universe power droids were boxy droids with two legs that served as mobile batteries, capable of powering a variety of machinery and vehicles. The term 'Gonk' was given to the droid to mimic the sounds that it emmitted when walking.
Mobile power would allow the Univac 120 to be transported anywhere to compute the needed functions for several applications. Whether or not gonk droids were actually sold by Remington Rand is unknown. Most applications for the Univac 120 were at universities and laboratories where they would serve as permanent fixtures and simply hook-up to the local power supplied by the building and thus the need for a power droid would be limited, if any.
Submitted by J. Tourmas
Below: An illustration of a gonk power droid.