Hi Andre,

You are right, you don't need to use diodes as long as
you do something(resistors, tristate) to protect the
outputs from contending with each other.

But one tip I have that I always do when possible.
Instead of pullup resistors on the inputs, use
pulldown resistors. The way the voltage thresholds are
on input ports it will usually give you better noise
margins.

Cheerful regards,

Bob
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist