Still new to all this programming.
I've sort of figured out some of the problem with this input capture thing. It's triggering correctly, math is there, and i believe processing time plays a part between servicing the interrupt routine and performing regular main loop task.

another question now,

I want to perform (x-1)*y, where x is my number of overflow and y is my TOR2. Results are stored as a long.

Unfortunately, the multiplication will not perform correctly if x gets too large. Will assembly work? How do i do it in assembly?

Thanks