Maybe this will do it:

1: Maintain  a buffer that has room for about 10 characters.

2: When receiving, as soon as you get a character immediately drop CTS.

3: The PC will continue to send for a bit. Receive those characters and put
them in the local buffer. Note that the 16550 will send the characters one
right after the other, so if more than a few bit times go by without seeing
a start bit then you know no more bytes will be coming.

4: Process the characters in the buffer.

5: Raise RTS.

6: Go back to step 2.

Bob Ammerman
RAm Systems
(high performance, high function, low-level software)

http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics