Just as an aside, well... I was fuzing with this out of curiosity, and I never was able to make a USB serial adapter spawn a console out of /etc/ttys automatically. The oft-quoted "use 'screen' to start a getty" manual process works, but trying to adapt the procedure that works for built-in serial ports (on old G3s or Xserves) faceplanted. I wasn't able to Google an example of someone making it go. (Closest I got was someone saying they couldn't make it work on a Mac Mini+USB dongle either.) Anyone here ever bothered?
Configuring a serial console is of course child's play on any other UNIX...