Dos was never based on Unix, in fact, its so different to Unix that the notion of it is Insane.
The /dev/ bit is probably what tells the system that it is a device, but opening a file with the typical API called "Con", "Aux", etc is basically opening a device. Dos has no /dev/ directory on the filename, no such thing as device nodes, just a crude API for input/serial/printer devices.
It is NOT unix. Also, CP/M had the same thing.