If you are having trouble, first make sure you have the current version of FORWARD. In SSW IDL type:

• Run the tests:

To be sure you have what you need it is a good idea to run the tests and if they fail, double-check you have installed the packages (e.g. through ssw_upgrade) AND included them in your SSW_INSTR list.

• FORTRAN compiler trouble shooting:

32 bit vs 64 bit—issues most likely with G77:
If you are running 32-bit G77 compiler on 64 bit machine you may run into problem because 64-bit machines differ in the way that IDL/FORTRAN read/write works with F77_UNFORMATTED, you MAY need to tell the code to work in 32 bit explicitly.
You can try changing these lines in $FORWARD/FORCOMP/makefile:
--> OPT= -m32 -ffixed-line-length-none
--> LFLAGS= -m32 $(DEBUG)
***NOTE some have found this step causes library issues (but see next comment). You should first try with the -m32 option, and see if you have I/O problems (it will complain it does not find a file).
You might need to make sure the 32 bit libraries are installed as well. For example, Linux users have had success with installing the "glibc-devel.i686" package.

• Windows trouble-shooting:

Windows Trouble-shooting Guide. (no promises).

Point of contact for questions: "sgibson 'at'".