[Dx4win] Help debugging COM port problem

[Jim Reisert AD1C]

Hi Folks,

A user who lives two time zones away called me today.  He is having
problems with radio communication after he got a new computer.  The
radio is a TS-940, using the driver for TS85--950, 4800 baud.  The COM
port is via a USB-to-COM adapter (brand unknown), device manager says
it's running on COM4.

The radio worked on the old computer (probably had a real COM port).
The radio works on COM4 port using MixW software, but it does not
communicate with DX4WIN.  He double-clicks on a spot, but the radio
does not QSY.

Does anyone have experience debugging this sort of problem?  We've
already gone through the windows XP device manager, as well as his
DX4WIN preferences.  We tried turning RTS and DTR (?) both on but to
no avail.

Thanks - Jim

-- 
Jim Reisert AD1C, <jjreisert at alum.mit.edu>, http://www.ad1c.us