I guess it's a bit more than just the timing . . .

You will have to shift the bits in and out "manually"
and your Slave Routine will have to interrupt driven.

This is probably a good questions to our Experts (Melanie?)

As Mentioned earlier: I haven't had any luck yet to run a PIC as 1-Wire Slave.

But if you manage to get this working I would be interested in your solution.

rgds: