I have been to http://http://dt.picbasic.co.uk/ a number of times to refresh myself, but I admit, I haven't mined it thoroughly. I went back and found a couple of nuggets. One was in "DT's other code examples" that gave a better explanation of IOC interrupts, the other was by mpgmike named http://dt.picbasic.co.uk/INT16/Customisation.

I had found his explanation on the forums of the PIC18's, but couldn't quite sort it for the lesser PIC's.

bo