Data Media Printerinterface
A device from Data Media for connecting 2 (or 3) printers to the CPC.
The printers are software-selectable.
Details on how this is implemented are unknown. Looking at the picture in the adverts it seems as if the adapter connects to the CPCs printer port (rather than to the expansion port)? If so, the selection would probably work by sending special character(s) to the printer port (rather than by using a separate I/O address)?