An experiment is described in linking to a large digital computer at data rates in the order of 107 bit/s. The system is based on standard British Post Office microwave equipment and well established high-speed wire links; the interface between the two sections uses the CAMAC-system convention. The total system is described, and details are given of some of the equipment not previously published. Important features of the system are the termination of both ends of the link in a high-level-language module (in this case PL1), executing in a multiprogramming operating system, and corrected error rates better than 1 bit in 109.