"Also don't forget that port pins p1.0/p1.1 do not have internals and need externals."

Just want to mention that that must be a derivative specific.

With all the bells and whistles added to the more complex of the new derivatives it is very advisable to carefully read the data sheet re pull-up. E.g. The P89C51Rx2 does have pullup on p1.0 - p1.5 but not on p1.6 and p1.7.

Erik