MS-DOS (MicroSoft-Disk Operating System) is an operating system with a command line environment created by Microsoft. It was the most widely used member of the DOS family of operating systems. In the 1980s it was the dominant operating system for the compatible PC (personal computer) platform. It was gradually replaced by various versions of the Windows operating system.
The MS-DOS operating system was released in 1981 and eight major versions followed before Microsoft stopped developing it in 2000. It was Microsoft's flagship product, gradually transforming it from a programming language company to a software development company and applications as MS-DOS evolved into the Windows operating system.
So below you will see an advertisement from the dark ages of computers.
This ad ran in several magazines, including InfoWorld. “MS-DOS gives you the only complete set of software tools for 16-bit systems”. InfoWorld. Vol. 4, no. 15. April 19, 1982. Pg. 10. ISSN 0199-6649.

With information from wikipedia.org
