Dear Sir, I am working on MCNP6 Monte Carlo Transport Code, which can be compiled by using gfortran Version 4.8.5 through 6.4.0. - I located and downloaded a gcc 4.8.5 package from a mirror site. - I installed Cygwin using setup-x86_64.exe on Window 10 computer. This Cygwin includes cygwin-devel 3.2.0 and gcc-fortran 9.3.0. Please let me know how to build a gcc in Cygwin with gfortran 4.8.5 replacing gfortran 9.3.0. With best regards, CM Kang
