I'm using #int_rb and it is interrupting at a rate of 9khz and nothing is changing on b4-b7, I have it to tell me when my quadrature pulser starts to turn. I have Enable_interrupts(INT_RB); in my initialization. #INT_RB RBIFINTERRUPT(){ /* did anything change */ TOGGLE_DEBUG2; // toggles an output pin for debug DISABLE_INTERRUPTS(INT_RB); QuadratureDecoder(); ENABLE_INTERRUPTS(INT_RB); } Can someone tell me what's wrong or it this a bug in the compiler. Thank you Jason