by inference from the data sheet for the microchip pic 18f8520, (
http://ww1.microchip.com/downloads/e...oc/39609b.pdf), the sixteen analog/digital pins on the controller will be connected to ports D and E on the microcontroller as these are configurable as either analog inputs or as digital input or ouput pins. the six interrupt pins are probably connected to port B, which can be configured for hardware interrupts, though these pins might also be useable for digital i/o. no way to guess where the motor ports are connected except that they are probably not connected to ports B, D or E. all of this could be doped out with a little patience and an ohm meter, but i'm probably not the guy to do it and definitely not today.
i do know that two of the pins on the serial port are connected to pins rc6 and rc7 on port C, these being the transmit and receive pins on one of the 18f8520's uarts. i have verified this with a meter.
it may not be unreasonable to guess that the two pins labelled tx and rx are attached to pins rg1 and rg2 on port G, these being the transmit and receive pins of the other uart.
that's all i've got.