If you have the source code, we can help you to get it running with a current Fortran compiler. Given the date, it is probably Fortran IV or Fortran 66. This is the first time that I heard about Cromis, and I suspect that you will have problems with I/O unless you can acquire compatible I/O devices (paper tape reader and punch? mag tape? acoustic coupler?). Do you have an OS for it?
The link that I listed says that the XMAS and XMAP sources are contained in a pair of 2400' magnetic tapes, using the EBCDIC character set. In 1975, there were few PCs (the IBM PC was not yet present), and they ran either CPM or the Apple OS; therefore, even if I had the CROMIS magnetic tapes today, I would not know how to go about reading the tapes and getting the files into a Windows or Linux computer.
FWIW: To those not familiar with bit-slice build systems please consult: https://core.ac.uk/download/pdf/162159971.pdf
Intel was not the only manufacture of bit-slice components, AM 2900 series was also commonly used. (to which I have had the pleasure of experiencing).