set modem type none        ; There is no modem
  set line /dev/ttyS0        ; Specify device name
  set carrier-watch off      ; If DTR and CD are not cross-connected
  set speed 19200            ; Or other desired speed
  set flow rts/cts           ; If RTS and CTS are cross-connected
  connect                    ; Enter Connect (terminal) state

Also add ttyS0 to /etc/securetty

-- MattWalsh - 01 Jan 2007