9 - Unix and Other Operating System Philosophies

Abstract

The aim of this chapter is to review design philosophies of three historical operating systems—the Atari home computers, Microsoft's Disk Operating System (MS-DOS), and VMS. Newer, faster hardware eventually came along, causing these operating systems (OSs) to fall into disuse. Without the portability of Unix, they could not keep up as hardware designers produced machines with increasing amounts of storage, specialized peripherals, and advanced graphics capabilities. The one exception is MS-DOS. MS-DOS is not a portable operating system. It was ported to progressively more powerful machines, but they were all of essentially the same architecture. The Atari 800 and its less expensive sibling, the Atari 400, garnered a respectable share of the home-computer market in the early 1980s. Primarily targeted as a machine for game enthusiasts, its claim to fame was its advanced graphics and sound capabilities. The designers of Unix and the Atari Home Computer's operating system had a common goal in that they both wanted to build a system for playing games–namely, Space Travel on Unix and games in general on the Atari. Before the advent of Microsoft's Windows NT and successive Windows generations, MS-DOS, was the operating system under the covers of the then current personal computers. At one point, over seventy million people used MS-DOS daily. MS-DOS can easily claim to be the most successful non-Windows operating system in history. If MS-DOS was the ruler of the PC operating systems before Windows came along, Digital Equipment Corporation's VMS s was the king of minicomputer operating systems. Before Unix had caught the world's attention, no other single operating system in the minicomputer space had earned such a wide, loyal following.