Microsoft's Disk Operating System (DOS) is generally thought of as the original operating system for Intel-class computers. Unlike the other OSs described in this book, DOS runs on anything, from a lowly original IBM PC with an 8088 CPU to the latest Intel Pentium III or AMD Athlon system. (Most more advanced OSs require at least a 386 to run.) In its long history, DOS has spawned quite a few versions, variants marketed by both Microsoft and IBM, and outright clones. Many of these products are still available—and can be used for productive work—today.
Varieties of DOS
When IBM released its personal computer (PC; a term that's now often used as a synonym for Intel-based computers), it needed an operating system. Rumors and urban legends ...