Interface 1 offered two network ports, allowing up to 64 ZX Spectrums to be daisy-chained using network leads up to 3 m (10 ft) long. The network, called ZX Net, used a proprietary CSMA-like protocol. Data could be sent or received at 100 kbit/s either to or from a numbered workstation, or broadcast to all nodes, allowing one machine to act as a server.