Abstract: A network extender for a computer network including multiple computers interconnected with a shared, common memory. A computer system interface interconnects the multiple computers and controls data flow between the multiple computers and a memory controller connected to the memory. First and second identical interfaces are respectively connected in data communication with the computer system interface and the memory controller. Each interface includes a circuit for converting parallel data to serial data format and a circuit for converting serial data to parallel data format. The parallel to serial converting circuit and the serial to parallel converting circuit of the first interface are respectively connected to the corresponding serial to parallel and the parallel to serial converting circuits of the second interface by serial data communication conductors.