Another question, my design always has 2-wire RS485 for multidrop communication and I think no way to use IAP via RS485 (no signals to control Reset and /PSEN pins of uC) , or am I wrong? Adding a RS232 port for IAP is the only way to go?
I have "hammered" Philips on this issue to no avail. I have, so far, put 232 on 485 boards with a nugget to switch mode.

Erik