The system architecture is a simple series of standard PCs communicating via Ethernet. The main simulation runs on one PC and pumps in/out data packets to the other PCs.
The main simulations PC runs the aircraft model in its entirety. It receives cockpit I/O and visual terrain feed back. It outputs the display data to each graphics PC, the cockpit DO/AO data and the visual interface data.
There is a general display program that runs on each of the graphic display PCs . It can be configured to be the L/R PFD, L/R ND the system display or the EWD.
The MCDU runs in its own PC as it is not strictly a real time simulation. Its data is sent to a FMS simulation running in the main aircraft simulation PC which handles the steering commands etc.