Norsk Data ND100 emulator
See ND100 emulator project at NDwiki. This is a copy of the original code repository (to be precise, of the v0.2.4 tarball), because the original site has been offline for a few years now, and the domain has expired.
For a more working emulator, look at RonnyA's fork: nd100em (check out the floppy branch). Or jdo-geek's fork: nd100em - you will have to look at branches here too.
Requirements libconfig is required. There is a FreeBSD port devel/libconfig.