Dear R-Users I was trying to call a Fortran 77 subroutine from R 2.0.0 in Windows XP. I have Rtools, Perl and MinGW as described in http://www.murdoch-sutherland.com/Rtools/ with path sets. When I use C:\R\rw2000\bin>Rcmd SHLIB test.f, a test.dll is created without error and located in that directory, but when I call the subroutine in R 2.0.0, R crashed and I got an error message as follows: Rgui.exe-Application error the instruction at "0x5ad71531" referenced memory at "0x00000014". The memory could not be "read". I believe that the Fortran 77 code is causing no problem. Also, please note that the same Fortran77 subroutine was called successfully in Unix version of R. (test.so was created accordingly). I am wondering whether R for Windows call Fortran subroutine in a different way than R for Unix? Any insight would be highly appreciated! Thanks! Yunming Mu