in some of the example code i found on keil's website, they set the ports to be inputs by initially writing 0xFF to them. I know all the ports (i think) start out as 0xFF, so since their latches... this shouldn't change anything should it?

Nope. It doesn't change anything... ASSUMING that nothing was changed after RESET by another pioece of code. But, what it DOES do is give the software developer confidence that the port bits are in the right state.

It's kinda like a gun. When you take down your shotgun to pack up and you know that you unloaded it before you put it away last time are you just gonna ASSUME that it's empty and start clicking away on the trigger? If you've ever taken a gun safety course, you'll know that the first this you do with a gun is to make sure it's NOT loaded.

That's all we're doing by setting the port bits high.

I'm still not quite sure about how all that directional setting goes on the 4 various ports that are available.

Basically, all 4 ports are identical with the exception of Port 0 (since it's usually connected to the low byte of the address bus and the data bus).

Jon