A local area network comprising a plurality of terminals (10, 11, 12) interconnected by a communication bus (13). Each terminal comprises a memory (16), a main processor (18), and a co-processor (15). To transmit information in a communication mode, the main processor loads data into a transmit buffer area of the memory, and the co-processor reads the data from the transmit buffer area and transmits a packet on the communication bus. Similarly, the co-processor receives data from the communication bus and stores it in a receive buffer area from which it is read by the main processor for use. In an alternative mode, called the direct transfer mode, the co-processors are reconfigured so that data for transmission is read from the actual locations in memory where it is stored (not the transmit buffer area ), and received data is stored in storage areas where it is expected to be used (not the receive buffer area).