Quote Originally Posted by BrianT View Post
Simply reading TMR0 or TMR1 is NO guarantee of a random seed.
Agreed 100%...but...if running on an internal oscillator, it could vary with temperature, perhaps far enough to mess with the seed enough. After all, theoretically, it only takes a single bit difference to change the order of things completely...theoretically that is
And exact temperature, therefore precise oscillator speed, is truly indeterminate, if, as you say, you have an external event trigger that is nonperiodic (aperiodic? anti-periodic? periodic-less?)