By using the internal USART and HSEROUT...
@20 MHZ
Code:
DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h
DEFINE HSER_SPBRG 159 ' 7812.5 Bauds
@10mhz
Code:
DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h
DEFINE HSER_SPBRG 79 ' 7812.5 Bauds
and blah blah blah for other speed.

I did a simple calc software for that few months ago.
Download here