DOSEMU, DOSbox and FreeDOS. I'd have to dig back into my setup to see what I did to configure DOSbox - will update the thread next time I do.
I just set up a new mini-PC (Shuttle DS-61) for computer-controlled scanning. The OS is Linux Mint 19.3; I installed the latest DosBox (0.74.0) and followed the guidelines on the Probe "Resources and Links" section.
With one exception: Rather than changing the ownership of the ports, I added my logged-in user to dialout.
The DS-61 has two serial and a bunch of USB ports. I added both physical serial ports to dosbox.conf and set the speed of each using the stty command (as commented on Probe's Resources page). If the settings aren't persistent between reboots I'll look into a shell script that sets port parameters then launches DosBox.
The new PC has both ProbeV7 and Probe1K installed; a PCR-1000 is attached to COM1 while the Optocom gets COM2. In DOS mode I run one or the other, and the Optocom configuration tool also works as intended through DosBox.
VirtualBox 6.1.32 is installed and a number of VMs including FreeDOS 1.2 (copied from the system I'm replying with) reside on the drive. I've tested Spectrum Commander IX, ScanCat Gold, Icom's PCR-1000 program and a few other utilities on the platform. All see either receiver and control them without issue. The USB ports will be used to attach USB sound cards or USB-serial devices for additional I/O.
Next is WSJT-X and other ham-related s/w, though this kit isn't intended for full-blown transceiver operation. It's more of a portable data-gathering platform.