I want to configure Port A,pins 0-7, as digital inputs - WITH THE INTERNAL PULL-UP RESISTOR. I want to do a byte write to the DDRA, and then a byte write to PINA The Pseudo code to do this is:
write 00h, DDRA ; write 0's in all bits of DDRA, config IC pins as inputs
write ffh, PORTA ; write 1's in all bits of PORTA, configure the internal pullups on the 2560
AWOL:
Have you thought of using the search facilities?
Of course, but it would be more efficient (and a little more helpful) if the person/expert who knows where the definitive reference is located to offer a pointer, thereby reducing the number of dead ends global searching tends to uncover.
AWOL:
You were given pretty precise search terms.
More 'efficient' for who?
For me of course, because I am relatively new with this programming language and some of the very strange wording for some of the concepts (e.g. 'shields'!?!?!?!?), and had no clue that your words were so precise. Perhaps a less laconic answer would have been more direct: e.g. search the arduino site for "direct port manipulation."