<CP/M. You can download the source, but it's not "Free Software". You hav <to get a license from Caldera for commercial use. Inflact the only question was is the source available (no other qualifiers). Ok then P2dos, a clone that is a direct replacement and improved. there are others (suprbdos, Zsdos, Zrdos). See my earlier post. The question didn't qualify commercial or not. If you allow for non commercial/student use the list is quite large. Allison