The control of systems with time-delay elements is reviewed. The differences between continuous and sampled-data control are discussed. A control method (for digitally controlled systems) is proposed based on the method due to O. J. Smith for continuously-controlled systems with a single delay. The effects of imperfections in the system model, and the effects of disturbance to the system are described and analysed. The method is extended for cascaded and other systems where the effect of delays is inseparable from the plant dynamics. Simulation studies using a hybrid computer are presented and discussed, in particular the effect of the use of short and extended shift registers for the simulation of pure time-delays is given detailed treatment.