First, what is Windows NT? It’s the first fully 32-bit Windows operating system. It’s the predecessor of Windows 2000, XP, Vista, Windows Server 200x – you get the idea. NT was released in July 1993. The name “NT” was actually named after the codename of the Intel i860 processor, “N-Ten”. But, for marketing purposes, Microsoft expanded the letters to “New Technology”. The original concept was to have common code running on top of a custom Hardware Abstraction Layer (HAL). The scope was scaled back when they dropped support for MIPS and Alpha.
The chief architect of Windows NT was David Cutler. Before NT, he developed the 32-bit OS for Digital’s PDP-11 (RSX-11M). He was currently in the process of developing the OS for the RISC Machines. Many of the concepts in these Operating Systems were used in the NT Operating System. In 1988 Cutler and his team were let go, they were working on the new OS that was going to lead Digital into the 90’s. Microsoft scooped him and some team members up quickly. Five years later, Microsoft NT 3.1 was released in 1993.
Just because I think this is somewhat entertaining, check out the minimum hardware requirements:
NT 3.1, CPU – 386, 25 MHz , RAM – 12 MB and free disk space 90 MB: released July 1993
Windows 7 – CPU-Pentium III, 1GHz, RAM – 1 GB and free disk space 1 GB: released October 2009
Much of the terminology in NT came from the VMS environments. The Windows NT Kernel and Executive subsystems are based on the VMS system. The Executive subsystems include the process manager, the scheduler, memory manager and IO managers. The two OS’s are so similar that some people have said you can read parts of a book on VMS internals and data structures and it holds true for the NT OS as well. There are way too many similarities to go into. If you are interested, there are several articles about this topic.
There is a big difference in the process manager. NT’s schedule gives CPU time to a thread, not a process. Funny, Digital released this functionality in VMS OS Version 7 released in 1995, after NT was released. NT was released with event wide logging and a configuration database (Registry), guess what, VMS 7.2 was released in early 1999 and it included both of these functionalities. Also interesting with the OS structure being so similar, Digital came out with clustering in 1984 but Microsoft didn’t release this functionality until late in 1997. So, you can see how closely these two operating systems track.
If you’re interested, you can read more details about the similarities and differences here: http://www.krsaborio.net/research/1990s/98/12_b.htm
My professional career started as a VMS system administrator and then I transitioned to Windows NT. You can see by some of the history that I’ve outlined, that this was a natural and easy transition to make since many of the concepts that I all ready understood carried over to the Windows world.