The article mentions they don't need DOS anymore, so they seem to be past that particular problem. It could have been as simple as something like FreeDOS on mo

The article mentions they don't need DOS anymore, so they seem to be past that particular problem. It could have been as simple as something like FreeDOS on modern hardware didn't work because it was written to use a real serial port and not something like a USB to serial adapter. And perhaps until recently, they didn't have anyone to help figure out how to bridge something like that through an emulator or vm passthrough device, etc.