hi

i read from the data sheet that the 8051 ports can be made input by writing all 1's ( shown in the program below).

mov p1,#0FFh ; port 1 as input

so what do i need to do to output all 1's at the ports. will in that case the ports become input?

also do i need to write all 0's to the port to make it output. So if i have a interface connected to a port 1 and the interface sends all 0's to the port, so will the port become an output?

regards
peter