Mike wrote: I'm trying to discover if the AuxBus is bi-directional, especially for the K60XV. Is there any info on the AuxBus ? Can't help you with the archive, Mike, but yes the AuxBus is Bi-directional. Go to the MicroChip web site and check out the PIC controller documentation. It is all there. 73, Jim W4ATK K2/100 #4028