This is an early Donner 3500 (serial num 107) portable analog computer from 1959. This unit may be one of the oldest working portable computers known. The video shows the solution to Demonstration Problem B in the appendix of the manual. I do not have the plugs that came with the system so I improvised with bare resistors and a cap (close enough to demo)... For more information about this project visit http://vintagecomputer.net/browse_thread.cfm?id=247
