1) install gfortran compiler
2) download cd1_f90.bin and cd1_f90.xxxx.bin files
3) edit getbin.f to point to those files
4) edit the Makefile such that the uncommented lines read
FCOMP = gfortran
FCOPT = -O -ffree-form -fconvert=big-endian
export FORT_CONVERT100000=big-endian
5) run 'make synow'