Epson FX-1050 User Manual page 134

2. Carefully insert the pins on the optional interface board into the
mating connector on the main board. Secure the board with the three
screws provided.
3. Attach the plug end of the FG wire onto the FG pin located on top of
the interface board.
4. Set the DIP switches on the interface board according to the manual
that comes with the board.
Using Printer Options 7-29