Source code of Strauss Process

Dear all,

I want to simulate a Strauss Hard Core process in 3D. I have found  
that someone else tried to do the same and he recived this answer,

"If you need this immediately, I suggest you follow Brian Ripley's advice.
This probably involves downloading a source tar file of the R package
and finding the Fortran code in library/spatial/src/. The Fortran should be
edited to generate 3D patterns (it's not hard: everywhere you see 'x' and 'y'
just include 'z'). Then also edit the R interface to the Fortran."

But I can not find the folder library/spatial/scr.

Can anyone help me with this?

Thaks

Ismael.