This interface which is easily connected to the Spectrum expansion port provides two communication methods: parallel Centronics and the bidirectional RS232-C series.

The two communication methods can be connected simultaneously to two different pieces of equipment, such as a printer and a modem.

The software necessary for operation is written on EPROM and is placed at the high addresses of the ZX Spectrum memory (this interface is only valid for the 48K Spectrum), using the Spectrum initialisation when connecting it to the power supply.

The interface is controlled by means of the standard BASIC commands and some USR routines.