I know that there is a simple circuit (without using MAX232 or
4188/4189) to convert RS232 TTL to RS232 C.
The hardware for communicating from the PC to the PIC is quite simple!
The circuit for communicating from the PIC to the PC is more complicated
(I can't remmember it!) it has a MOSFET and same zenners.
All the hardware needed was once published in ELEKTOR, but I can't seem
to find it!

 Does anybody knows the circuit?

 Thanks,
 Cabral