I don't know what PIC you are using, so I can't look up the data for
myself, but maybe the problem has to do with your choice of oscillator.
Perhaps there is a prescaler issue or something as well.

Hopefully this might steer you in the general direction.

Josh

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completely foolproof is to underestimate the ingenuity of complete
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"Michael A. Powers" wrote:
> I wrote a program that interrupts on TMR0 overflows in the MPLAB simulation,
> but for some odd reason it doesn't work when programmed in a circuit.  I
> have confirmed that the rest of the program and TMR0 are working, but the
> interrupt just doesn't fire when put into an actual circuit.  What could be
> the problem?
>
> (TMR0 source is CLKOUT)

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