Released the actually much better debugged (;-) ) version: ftp://panteltje.com/pub/temp2.asm This one has a pulsed alert output on pin 2, and RS232 out on pin 5. You can set a threshold in the source. Pin 2 can drive a LED, or you can OR many of these PICs together. The alert will go away if the temp drops below the threshold again.
Do not use the old version, it had a high an low byte swapped somewhere, and a wrong init on some timer.