Yaesu CAT/Digital Interface
CAT Control and AFSK soundcard audio interfacing for the FT-897D (and FT_857)
Note that for use with Ham Radio Deluxe, neither the RTS nor the DTR connection nor the Opto-Isolator are needed. I discovered this when the rig was connected to a laptop during power on the DTS/RTS lines are not well behaved, causing a PTT at the rig. Ham Radio Deluxe is able to key the rig via CAT control, so this is not needed, but the DDTS/RTS mechanism via the opto-isolator is provided for other software which may not use PTT via CAT command.