Abstract: A computer system consists of a central station and a plurality of remote terminals, some having a relatively low data acceptance and/or transmission rate and others having a higher data rate. The communication link between the central station of the terminals consists of a low speed channel and a high speed channel. The terminals are permanently connected to receive signals over the low speed channel and a control signal, sent by the central station, to a particular addressed terminal over the low speed channel connects an associated terminal to the high speed channel.