Hi Tony, Thanks for the explanation. I wanted to make sure I understood. Is the TRIS instruction used only for setting up PORT input and outputs, or can it be used for other uses? thanks again Bernard -- Bernard Tyers*Dept. of Physical Sciences*Dublin City University*P:01.7005273*L:N117*W:frank.physics.dcu.ie/~bty -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu