Is NT really new technology?

 Mark Russinovich

Is NT really new technology?

When Microsoft released the first version of Windows NT in April 1993, the company's marketing and public relations campaign heavily emphasized the NT (i.e., New Technology) in the operating system's (OS's) name. Microsoft promoted NT as a cutting-edge OS that included all the features users expected in an OS for workstations and small to midsized servers. Although NT was a new OS in 1993, with a new API (i.e., Win32) and new user and systems-management tools, the roots of NT's core architecture and implementation extend back to the mid-1970s.

And now...the rest of the story: I'll take you on a short tour of NT's lineage, which leads back to Digital and its VMS OS. Most of NT's lead developers, including VMS's chief architect, came from Digital, and their background heavily influenced NT's development. After I talk about NT's roots, I'll discuss the more-than-coincidental similarities between NT and VMS, and how Digital reacted to NT's release.

A Brief History of NT
NT's history is closely tied to that of David N. Cutler, NT's chief architect. After graduating from Michigan's Olivet College in 1965, Cutler worked for DuPont. Although computers weren't his first interest, he ran simulations on Digital machines as part of his job at DuPont. Before long, Cutler was knowledgeable about software and decided he wanted to develop OSs rather than application software. He joined Digital in 1971 and worked at Digital's famous "Mill" facility in Maynard, Massachusetts, developing OSs for the PDP-11 family. RSX-11M is the first OS in which Cutler incorporated major concepts and design principles that later surfaced in NT. RSX-11M is a PDP-11 OS Digital developed for industrial and manufacturing control.

In 1975, Digital realized that its competitors were developing 32-bit processors and that this technology would lure customers away from PDP's 16-bit architecture. Gordon Bell, a legendary figure in computer history and then vice president of engineering for Digital, drove the development of the 32-bit processor, which Digital eventually named VAX. By this time a star within Digital, Cutler was part of the initial VAX development team. Digital had charged Cutler, along with Dick Hustvedt and Peter Lipman, with designing VAX's OS, VMS. Digital's primary design goals for VAX hardware included backward compatibility with PDP-11 processors and enough flexibility that VAX could be the basis for low-end desktop workstations as well as enterprise-level servers. Digital also made VMS backward compatible with RSX-11M and designed VMS to run on different size machines. Of this development period, Digital states in its company history that it was "betting the business" on VAX and VMS. In an eerie echo of Digital's statement, Bill Gates recently claimed that Microsoft is "betting the business" on NT 5.0.

In 1977, Digital announced VAX-11/780 and VMS 1.0, making the first product shipments in 1978. As the project leader and one of VMS's main architects, Cutler continued work on successive releases of VMS, but he became restless at Digital. In 1981, Cutler threatened to leave Digital. To retain its star developer, Digital gave Cutler about 200 hardware and software engineers. Cutler moved his group to Seattle and started a development center. This elite group's goal was to design a new CPU architecture and OS that would lead Digital into the 1990s. Digital called the Cutler group's hardware project Prism, and its OS Mica.

In 1988, Digital executives cancelled Cutler's project and laid off many of its group members. Cutler decided to leave Digital, but before he could do so, Microsoft executives learned of the development and realized they had an ideal opportunity to hire Cutler. At the time Cutler left Digital, the release of VMS was version 5.0 (today's version is 7.1).

In August 1988, Bill Gates hired Cutler. One of Cutler's conditions for moving to Microsoft was that he could bring around 20 former Digital employees with him, including several Prism hardware engineers. Microsoft readily met this demand­the company knew hiring an OS architect of Cutler's stature was a coup, and few engineers had Cutler's track record. In addition, Gates felt that Microsoft's long-term future depended on the development of a new OS that would rival UNIX.

Microsoft's internal project name for the new OS was OS/2 NT, because Microsoft's intention was for the new OS to succeed OS/2 yet retain the OS/2 API as its primary interface. The success of Windows 3.0 in April 1990 altered Microsoft's thinking and its relationship with IBM. Six weeks after Microsoft released Windows 3.0, Microsoft renamed OS/2 NT as Windows NT, and designated the Win32 API (a 32-bit evolution of Windows 3.0's 16-bit API) NT's official API. Gates decided that compatibility with the 16-bit Windows API and the ability to run Windows 3.x applications unmodified were NT's paramount goals, in addition to support for portions of the DOS, OS/2, and POSIX APIs. From 1990 to NT's public release in August 1993, Cutler's team was in a mad dash to complete NT, and the project grew to involve more than 200 engineers and testers. Figure 1 shows a timeline of the major events in the history of NT.