On 2020-07-08 11:28, Tate Belden wrote: > I've several USB <-> RS-232 dongles around. As well as a few embedded > devices. They all "Just Work (tm)" on Redhat, CentOS, Fedora, Debian, > Raspian and Kali. Even if you did have an RS232 port on the box, the serial drivers for CentOS 7 have never worked correctly. I had an application using RS232 that worked perfectly under CentOS 6, and then worked intermittently under CentOS 7, and failed miserably on CentOS 8. The handwriting on the RedHat wall says, "nobody uses RS232 anymore!" I moved the app to a Raspberry Pi 3B+, using the USB serial adapters, and it works perfectly again. Todd Merriman Software Toolz, Inc.