Hi, I am new to FORTRAN and trying to debug/compile some code passed on to me. 2 questions: - What purpose does SUBST or DSUBST serve? - When I run my Makefile I keep getting the following error: 'PGF90-S-0026-Unmatched quote' According to the PG manual this translates to 'Integer constant is too large for 32 bit word' I have tried a bunch of different things but the issue is still unresolved. Any insight on this? Thanks!