/dev/cuad0: Device busy

[Eugene Grosbein]

> Personally, I never understood the concept of "dial-in" and "call-out"
> devices on FreeBSD.  I ran BBS software for years on both Apple II
> hardware and PC hardware; there was no distinction between such devices.
> A serial port is a serial port.  Chances are I'm not understanding why
> there's a distinction, but there doesn't appear to be any explanation of
> why there's a distinction within manpages or the handbook...

The distinction exists to allow an application to wait on the "dial-in"
port for incoming calls and another application to make outgoing call
mean time using the same port as "call-out" while the port is idle.

Eugene Grosbein