Jon Petty wrote:

> If I rs232 network multiple pics or stamps using separate RX and TX
> lines do I still need to use open source and open drain boad modes?

  Depends on your topology.  If you mean master-slave with one master
driving to RX on all slaves and its RX coming from TX on all slaves,
then you have two problems - the slave TXs will contend, and the loading
on your mater TX may be excessive.

  RS-232 is not suited for this.  RS485 is.

  You can certainly use RS-232 for a daisy-chain where every TX drives
the next RX in one great loop.  This requires no nodes to die, or a
bypass relay at each node (DPDT) for power-down.
--
  Cheers,
        Paul B.