Surely you do not remember this project, but to the operating system Microsoft MS-DOS That dominated the market for IBM PC computers in the 80s, some competitors came out, such as an MS-DOS 5 clone called PC-MOS / 386 created in 1987 and which was multi-user. The operating system could run native MS-DOS applications using the protected mode of Intel's 386 microprocessors and compatible chips. A breakthrough at that time ...
PC-MOS / 386 It emerged as an evolution of PC-MOS and was optimized, as its name suggests, for 80386 microprocessors, written in assembly language and also in C, capable of running Microsoft's operating system software and being bootable from a 3.5 floppy disk. ″ From where the system image was loaded, although it currently comes with CD-ROM drivers and some other new features.
Well now it is known that Roeland Jansen, one of its developers, will continue with the open source project. You can see more information about this operating system and about the development from the official website of the project. You can test it in virtual machines thanks to the virtualization software VMWare Workstation or Oracle VirtualBox, although if you have a machine from the 80s and diskettes of this type, you can run it on this physical machine.
The new release is under GPL license in its version 3, so it is a free and open source project. If you want to compile it, you will need a compiler from the early 90's, the well-known Borland C ++ 3.1, although other compilers could also work, this is the most suitable. Quite a hobby to get the operating system working and resurrect your old MS-DOS rig ...
Well, we already have two free DOS. : D