There are still quite a few RCA cables around here, and I can try the old computer again in this current setup as well as the new one (though my plan is to dedicate the old computer to doing this work in the background). My goal with setting up the office after construction was to have all of the various cables and plug lines generally out of the way, but the backs of the computers and other devices easy to reach if I need to change things out. This will be the first major test.