The story begins in 1981 with the purchase by Microsoft of the operating system QDOS (Quick and Dirty operating system), which after making a few modifications, becomes the first version of the Microsoft operating system, called MS-DOS 1.0 ( MicroSoft Disk operating System). 4c3s7
From here, there are a number of modifications of the operating system, up to the version 7.1, from which MS-DOS ceases to exist as such and becomes an integrated part of the operating system Microsoft Windows.
