My setup is a new (to me) FT-840, WinXP, HRD 5.0, USB to serial adapter w/ driver installed
The USB adapter is visible to the computer as COM4, but HRD is not talking to the FT-840. I attempt to Connect using any combination of DTR and RTS clicked on or off, and Auto-Detect for the speed.
Here's what I get:
Failed to read frequency.
Make sure your radio is switched on and not in memory mode.
If you are using a homemade/non-standard cable you may need to select RTS and/or DTR
I'm not certain if the FT-840 is in memory mode or not; while the manual has a section on setting memories I don't see anything about "memory mode".