On Fri, Sep 4, 2009 at 12:03, Mark Hibbeler<markhibbeler@xxxxxxxxxxxx> wrote: > <built-in>:0: internal compiler error: Illegal Instruction > > Mac-OS X 10.5 > downloaded fortran compiler and get the above error when executing code You need to provide a *lot* more information about the bug and how to reproduce it. Please see http://gcc.gnu.org/bugs.html Diego.