This extraordinary computer is one of only two Donner 3400 computers that are known to exist.

The Donner Model 3400 analog computer represents a critical period in computing history when analog computation was the dominant method for solving complex mathematical problems in real-time. Manufactured by Donner Scientific Company of Concord, California in the late-1950s, the 3400 was part of a family of precision analog computers that served aerospace, defense, academic, and industrial research applications during the golden age of analog computing.

On October 18, 1958 the Donner 30 (an earlier version of the 3400) was used for the very first public video game!! Using an oscilloscope with a five-inch screen, William Higinbotham demonstrated "Tennis for Two" where two people could move a ball back and forth across the oscilloscope's screen. An excellent article on this early game can be found at the Heinz Nixdorf Museums' website. (It is in German but your browser should translate it for you.)
We mention this because when Brookhaven National Labs wanted to recreate the original game for its 50th Anniversary, they could not find a Donner 30 computer. However, they did find a Donner 3400 which was very similar to the Donner 30.

Donner Scientific Company was established in the 1950s and quickly gained a reputation for producing high-quality analog computing equipment. In 1960, Donner Scientific merged with Systron Corporation to form Systron-Donner Corporation, creating one of the premier manufacturers of analog computers, electronic test instruments, and inertial guidance systems. Our collection includes two Donner 3500 analog computers...one made by Donner and the other by Systron-Donner.

The Donner 3400 was a modular, vacuum tube-based analog computer system featuring:
--High-precision operational amplifiers operating at 100 volts DC (standard for professional analog computers of the era),
Servo multipliers with 10-turn precision potentiometers for accurate coefficient setting,
--Integrator circuits capable of solving differential equations in real-time,
--Removable problem boards (Model 3430) that could be pre-programmed with patch cords and coefficient plugs, then swapped out in order to quickly change programs,
--Null voltmeter connections for precise calibration of computing elements.