Hi,
 I want to thank everyone for helping me out with info. on zero crossing
detectors without connecting 120 volts to my PIC. There seem to be two
camps, one using optoisolators and one using transformers. Since I am
using a transformer for my power supply anyway I thought I'd use that
approach. I'll put a 10k resistor from the high side of the 12 Volt
transformer on my power supply to a PortB interrupt on change pin. I
remember in the past there was some problems with the PortB interrupt on
change working reliably. Is that still the case or has Microchip fixed
it. The application is for a motor speed control so I'm sure the odd
glitch wouldn't be too serious, it just depends on how odd that glitch
actually is. Thanks!
                                                      Jim Ruxton