SCA CPC Prolink
According to the manual, the hardware works with the standard CP/M functions (ie. the original unmodified CP/M version that is included with AMSDOS). Accordingly, I/O ports must be same as with the standard Amstrad Serial Interface.
There seems to be no ROM, tape, or disc software included. According to the manual, Standard CP/M functions can be used. The manual also recommends a communications program called "MEX".
- RS-232 (SCA) Manual (pdf) (2 pages)