Main

Disk Operating System

• RDOS (Data General Corp)
• QDOS (developed at Seattle Computer Products by Tim Paterson for the new Intel 808x CPUs; also called SCP-DOS; licensed to Microsoft -- became MS-DOS/PC-DOS). This should not be confused with the Sinclair QDOS operating system of the same name for the Sinclair QL computer.
  1. MS-DOS (Microsoft's now abandoned DOS variant)
  2. PC-DOS (IBM's DOS variant)
  3. PTS-DOS (DOS variant by russian company Phystechsoft)
• DR-DOS (Digital Research's [later Novell, Caldera, ...] DOS variant)
  1. Concurrent DOS (Digital Research's first Multiuser variant of DOS)
  2. Multiuser DOS (Digital Research's (later CCI's. Real's/...] Multiuser variant of DOS)
• FreeDOS (an open source DOS variant)