Ok. Ill have a read through them. I thought the thing Darrel made was to make interrupts easier.

Can someone give me a bit of info on the pins used please. I can read those threads tomoz but i need to get the PCB designed ASAP. Do i need the zero-crossing diodes going to RB0/INT and the serial input go to just another normal I/O pin?

Is there a chip suited to this circuit? I see what Jumper was saying about having a 40 pin chip but space is tight and i wont need to expand on this project. If i have missed anything then ill find it when im designing the PCB.

If the worst happens and i cant learn interrupts fast enough then i can still use the circuit without PWM but the hardware has to be right. I can reprogram the chip but i cant remake the PCB