The ENIAC

A part of the Electronic Numerical Integrator And Calculator at the Army's Aberdeen Proving Grounds is visible here (it continues around the room). "Its 19,000 vacuum tubes, 1,500 relays, and hundreds of thousands of resistors, capacitors, and inductors consumed almost 200 kilowatts of electrical power." In it's original form, this brute was programmed by properly plugging in the maze of patch cords. It clocked at 5000 operations per second.

This is a U.S.Army photo, but the image and the quote are both thanks to Mike Muuss and his labor of love at http://ftp.arl.mil/~mike/comphist.