I'm building an embedded system right now with a PC-104 486 as the main
processor, and it is running short of serial ports.  Instead of paying the
$100 bucks for a serial port card, I had the crazy idea that we hang a PIC
or a DUART off of the Parallel port and write some drivers to get more
ports out that way.

Does anyone have experience with doing something goofy with the parallel
port this way?

It seems to me that with the 8 data lines, and 9 or so control lines we
ought to be able to control a 16550 or something similar.   Maybe a PIC
with some sort of control language to handle dual software UARTS?

The good news is that since the devices connecting to these serial ports
are TTL level serial we won't need level shifters.  A further cost savings.

What do you guys think?

-Erik Reikes