Interrupts on in 4200 bios?

Can someone familiar with what goes on in the innards of the 4200 tell me if there are one or more interrupts running as pat of the dynamic c runtime library stuff? I am trying to port my onewire stuff from another compiler/processor and after adjusting the empirically determined fudge factors in the delays, I’m wondering if the rabbit just punches out and walks out back to take a smoke every once in a while whenever he wants.