An amalgamation of sorts. Figured I'd post this in the Computers section in case someone else runs into the same problems I did:

The old shack computer (Windows 7) keeps on chugging away for things like controlling my various scanners via deprecated software packages. One of our new members (Mark, KE8NOA - an area 10M friend) convinced me to dip my toes in the FT8 waters, but the software requires an active Internet connection for time-sync purposes. No way I'm letting a Win7 box out on the 'Net (unless it's a VM that I can easily re-image) so I had to look at alternatives.

On this system (Shuttle SH67H3) Window 10 running as a host OS is questionable. That is, I've had more stability problems than running Mint Tricia (19.3) as a host, with Win10 as a guest. To be fair, Windows support of multi-monitor configurations (especially those connected via USB) is a bit better than various Linux iterations. I was weighing my options when Mark and I were chatting about WSJT-X on 10M and he remarked that he was successfully running the Linux version on Tricia 19.3. This galvanized me to give it a shot. Which went well - I removed the SignaLink connection from my Win7 system and it was pretty much a seamless integration with the Linux host. K1JT's site provides a how-to for the Linux installation.

Except for one little problem: My work area has four monitors - a 17" flat panel, two 24" flat panels and a second 17" flat panel. I can utilize the two 24" and rightmost 17" on my work PC while doing my day job, or switch video inputs via KVM or the monitors themselves and route them to one of several shack computers - including the Tricia host. What I missed with that setup is the ability to use the left 17" monitor as an fldigi (PSK31) or WSJT-X screen. That way I can work, monitor the on-air goings-on and click to QSO if I see something neat pop up on the digi-modes monitor. A number of USB-to-video adapters are on-hand here, most of which have DisplayLink hardware embedded in them. None would work quite right with this version of the OS so a little digging turned up a Diamond BVU-195. When I installed it, Tricia's native driver support picked up the device but it wouldn't let me initialize the monitor at its highest resolution. DisplayLink has Ubuntu drivers on their site - I downloaded the pre-20.x version, installed a few dependent packages then installed the driver and rebooted. All looks good except for the mouse pointer disappearing when the DisplayLink adapter was active.

We'll cut to the chase with a synopsis of what I did to make things work, after much Internet searching:

1) The EVDI driver has to have an entry in /etc/modules. Do this by "echo evdi >> /etc/modules". Similarly, in the /etc/modprobe.d directory an evdi.conf file must exist. Create it by entering 'echo "options evdi initial_device_count=1" >> /etc/modprobe.d/evdi.conf' (Use a value greater than 1 if you have more than one DisplayLink device attached to the computer).

2) My system required an entry in /etc/X11/Xsession.d to set display parameters using xrandr. The arguments used will vary from system to system, but in a nutshell I have three video devices connected - two onboard (DVI and HDMI). The DVI port is connected to an analog VGA cable through an adapter and the system thinks it's talking to a VGA device. It also never sets the VGA video mode correctly on startup. Thus, my xrandr file (named 90xrandr) issues a resolution set command then sets the primary video device (the VGA screen), sets display positions and finally turns the DisplayLink device on.

3) The mouse needs to be set to its fastest acceleration using the appropriate Settings applet. I used a "Custom Speed" with the slider all the way to the right.

4) Lastly, this DisplayLink article provided a solution to cure the mouse misbehavior - https://support.displaylink.com/know...ent-x-upgrades

I'm currently running the system on two of the three monitors - the rightmost 24" and the leftmost 17", which is the display being used for WSJT-X. Performance appears solid. The leftmost 24" can be toggled back and forth between work and play computers.