Solution Done...

Connecting directly the 80C31 lines into PC-BUS for data I/O would cause clock-syncro problems.

But after analisis, i can use a 8251 (UART) serial creating a new COM port. (of course an interface decoding ports using a 74HCT138)

Then the TX/RX UART from the 80C31 is connected in this "new" port.

The P0 and P2 for memory purposes(ROM,RAM).
The P1 for external.


Rob Tuninetti (Mendoza, Argentina)