Paul Brown wrote:

> The question is: who makes an RS485 card with a USART that has 9 data
> bits?

  Umm, all of them IIRC!  It's called "parity" and can be set as "stuck"
to "mark" or "space".  You set the receiver similarly and it signals a
parity error when it detects parity contrary to the current setting (as
it always does).

  The difficulty in this method is that it must be set up before sending
the character and only that character sent, waiting for the transmitter
to fully empty before setting an alternate "parity" and sending further
data.

  But - it's do-able.
--
  Cheers,
        Paul B.