a 12x12 led matrix sequenced row by row needs to be turned on at least 70 times per second, so the loop needs to run 70 times 12 per second, that translates to 1.2ms per row, if I read the DS1307 at this speed Im sure I'll choke it.

jellis, thanks for the offer, my email is pablou at gmail

I'll recheck Darrel interrupts, no matter what I do I always peek at his work...


thanks guys!