> I need to be able to establish communications (listen) and then
 > respond to incoming messages from the other computer.  C or
 > assembly routines would be great, but better is an explanation of
 > how the whole thing works UART and all.

Echomail suffers from a far too limited bandwidth to do the topic justice.
You're better off with saving your pennies and going down to you local
technical book store and purchasing something worthwhile. "C
Programmer's Guide to Serial Communications" is a pretty good start.

  cheers,
  david

---