Hi Francisco,

I am one of these dinosaurs that haven't learn to program in C. However, I can indicate how to set/clear a bit on a port. Hope it will be useful ...
Set a bit : SETB P1.3
Clear a bit : CLR P1.3

Note that the CLR instructions does not require the B (CLRB is not a recognized instruction...)

Hope it helps !

Daniel Sauriol, Montréal.