On Mon, 13 Oct 1997 15:41:00 +0000 Mark Brayford
<mbrayford@SPERRY-SUN.CO.UK> writes:
>     Depending on the baud rate error, it is possible you may get
>problems,
>     try putting a slight delay between characters, this will allow
>the
>     UART to re-sync every byte. (same both ways).

The UART always re-syncs on every byte, that's why it's called
asynchronous.  The stop bit provides the necessary pause.

The most timing error that can be tolerated is that which causes an error
of 1/2 bit after 9 bits, or roughly +-5%.  A PIC with external RC will
not meet this specification.  Use a crystal or ceramic resonator.

There are other reasons the data could be garbled of course.  If sending
the same character results in different characters being received, likely
the timing is way off and varying.  If the timing is slightly off, the
MSB will be the first to be affected.