IBM, CP/M, Microsoft, and creation of MS-DOS

(via ExtremeTech)
Found a rather interesting article on a website called that explains the origin of Microsoft's MS-DOS and thought it was interesting. The article itself is actually about why hard drives are labeled "C" by default, but it's not as interesting compared to the story of MS-DOS.

(via Wikipedia)
It all begins back in '80s. IBM was about to make it's presence felt in the personal computer market by introducing their IBM PC in '81 and they wanted their machines loaded with a then-popular operating system called CP/M, made by a company called Digital Research, Inc. What's interesting is that CP/M was itself based on the CP/CMS OS created by IBM back in the '60s. Well, things didn't work out for whatever reason, supposedly because the wife of the Digital Research refused to sign a non-disclosure agreement. So, not being able to license CP/M for their PCs, Big Blue turned to a little software company run by Bill Gates and Paul Allen called Microsoft.

You might have heard of Microsoft, it's sort of a big deal. I hear Gates and Allen did pretty well for themselves, too.

(via Forbes)
IBM wanted MS to create a copy of CP/M, so that it would be compatible with software that ran on CP/M. Microsoft in turn bought a clone of that OS called 86-DOS and turned it into MS-DOS.  In other words, MS-DOS is based on a clone of an operating system that itself was based on an operating system created by IBM. Now add in the fact that Windows is based off MS-DOS and that is one hell of a lineage. IBM would rebrand MS-DOS to PC-DOS for their own computers and later developed it into a separate product.

In case you're wondering about the C drive thing, it's because back when computers still used floppies, the disk drives were labeled A and B (if the computer had two). Hard drives weren't a common feature back then, but when they did become common, they were just naturally labeled C. Like I said, not as interesting as the creation of MS-DOS.