The Winchester Graphics System provides a facility for animation of molecular dynamics data. It features simple user setup of various picture types and realtime user control of speed and viewpoint during the animation. The system operates by preparing frames in display list format on a mainframe and storing them in mainframe virtual storage. During the animation the frames are sent at a user controlled rate of up to 30 frames/s via a minicomputer to a display system. The minicomputer also monitors user control devices to prepare viewpoint transformations. These viewpoint transformations are applied by the display system. The user setup of different pictures is simplified by a powerful relational database and by ease of adding new application programs. The realtime display relies on substantial mainframe memory, and a high bandwidth path to the display system. We have applied the system to a simulation of the dynamics of avian-pancreatic-polypeptide. Stick diagrams, surface plots and distance matrices have been used. © 1983.