Microsoft Windows Nt

Those who do not understand Unix are condemned to reinvent it, poorly. -- Henry Spencer

The Microsoft Windows NT Operating system. See http://www.microsoft.com/ntserver/ for more details.

Originally designed by DaveCutler, creator of VAX/VMS (see VmsOperatingSystem), over a five year period, to be OS/2 3.0. With the success of the MicrosoftWindows OS, it obtained the Windows GUI. Unlike Windows, MicrosoftWindowsNt has NEVER had any DOS or 16 bit code underneath. It was designed from the beginning to be a stable, modern OS . It has a WOW (Win16 on Windows NT) that *emulates* Windows and DOS in a protected mode subsystem. In fact, all the APIs are in subsystems (POSIX, OS/2 1.x, Win16, Win32). The subsystems "talk" to the layered stack that has the kernel, executive services and the Hardware Abstraction Layer (HAL).

Now has become WindowsTwoThousand and WindowsXp.

AfterLife for WindowsNt

MS is, and will continue to support till end 06, NT for "selected" customers for fees around 200K for security patches and the like.

These fees are probably accepted because customers cannot get the resources to upgrade applications being run on NT.

See http://www.redmondmag.com/features/article.asp?EditorialsID=469

ImplementationContradictsDesign?

Not really. NT (and successors) are pretty stable.

Anyone else remember the decision to move graphics drivers into ring 0 (i.e. unprotected kernel access) because of NT's poor graphics performance? The change sped up rendering but allowed a badly-written driver to bring down the entire OS.

Some related trivia: I used to use NT and have long, glorious memories of having to install it over and over again. After the hundredth install, I bothered to notice something peculiar on one of the early setup screens... it looked distinctly like a Unix directory.

Why should this surprise anyone? NT and UNIX are far more alike than not. Many, many of the senior engineers on the NT team have many years of experience using various UNIX operating systems. There is nothing distinctively "more UNIXy" about OS install than any other part of the OS -- like many other OSes, parts of NT resemble UNIX, VMS, and many other modern operating systems.

UNIX isn't some unapproachable, isolated canon. Good OS designs and implementations influence future OS designs and implementations.

-- ArlieDavis