MS-DOS user experience was extremely similar CP/M. In fact, one could safely say MS-DOS/PC-DOS only existed in the first place as a "quick and dirty" approximation of CP/M. (because IBM and Digital Research could not agree to licensing terms to bring CP/M to the IBM PC)<p><a href="https://en.wikipedia.org/wiki/Digital_Research#CP/M-86_and_DOS" rel="nofollow">https://en.wikipedia.org/wiki/Digital_Research#CP/M-86_and_D...</a>
CP/M felt like it had its roots in the same tree Tops-10 sprung from.<p>PIP, Peripheral Interchange Program existed in Digital Equipment, PDP series. It was how you glued IO into the card deck and the line printer or tape printer.<p>MS-DOS might well have been the category-killer 'avoid paying the IPR tax' OS, but they also said "our customers have never seen a Digital equipment PDP minicomputer, or mainframe. Lets do some things differently"