Over the past several years, however, we have found a few Donner computers and parts online. After some painstaking restoration work, we now have a working version of a Donner Model 3400 analog computer that essentially does the same thing as the original model used in Tennis for Two. We are now integrating the Donner computer into our 1997 game board. This requires removing the extra components that belong to the solid-state devices and restoring the circuit to its original 1958 state. (via Resurrecting One of the World’s 1st Video Games : Brookhaven Bits & Bytes)