FreeDOS is actually derived from DRDOS, which in turn came from CPM/86, and then back to the original CPM on the 8080. Novell bought (Intergalactic) Digital Research, divested DRDOS to Caldera along with their part of the UNIX rights, and Caldera donated it to the Free Software community.
By the way, the original CPM was pretty much a re-write of Digital Equipment Corp. RT11, down to device naming, PIP and everything.
DOS stands for Disk Operating System
I can see the argument. Unix needs a hard disk, but all the other criteria could be met. I started using Unix on a PDP11 with 128KB of memory and 7.5MB of hard disk space. DEC did not publish clock speeds of their computers, but bearing in mind that a VAX 11/780 as the benchmark of a MIP, and a PDP11/34 was a MUCH earlier machine than the VAX, the computing power was probably comparable to an 8086. I believe that Unix would have been possible, but you must also consider MPM (a development of CPM) from Digital Research, which was available before MSDOS. This already had rudamentry multitasking, and the concept of user protection for disk files. DR was much more in the grove for proper OS development than Seattle Systems (who developed the MSDOS 1.0). IBM were foolish to believe that Microsoft were able to produce a real OS.
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FreeDOS is actually derived from DRDOS, which in turn came from CPM/86, and then back to the original CPM on the 8080. Novell bought (Intergalactic) Digital Research, divested DRDOS to Caldera along with their part of the UNIX rights, and Caldera donated it to the Free Software community. By the way, the original CPM was pretty much a re-write of Digital Equipment Corp. RT11, down to device naming, PIP and everything. DOS stands for Disk Operating System
I can see the argument. Unix needs a hard disk, but all the other criteria could be met. I started using Unix on a PDP11 with 128KB of memory and 7.5MB of hard disk space. DEC did not publish clock speeds of their computers, but bearing in mind that a VAX 11/780 as the benchmark of a MIP, and a PDP11/34 was a MUCH earlier machine than the VAX, the computing power was probably comparable to an 8086. I believe that Unix would have been possible, but you must also consider MPM (a development of CPM) from Digital Research, which was available before MSDOS. This already had rudamentry multitasking, and the concept of user protection for disk files. DR was much more in the grove for proper OS development than Seattle Systems (who developed the MSDOS 1.0). IBM were foolish to believe that Microsoft were able to produce a real OS.