Thanks for your answer Raghu. I have no problem with the DIP switch connection or reading logic, my concern is with P2 then being driven by MOVX instructions. Could I damage the chip if it ever tries to drive an output high (as an address line) when that input is tied to ground by the DIP switch? The chip is an 8751H.

Note that normally, this shouldn't happen since I will be using P2.0 to drive the 8155's M/IO line to write to the 8155's ports, and P2.1 to P2.7 will read 7 positions on the DIP switch. I guess my real concern is, will I be able to read P2 just like a normal port if no MOVX instructions are being executed, as opposed to having the port hold an ouput value that MOVX insturctions would modify. In such cases, I realize that latching the outputs to an external buffer would be necessary, strobed in there by another port's pin. That is not what I want to do here.