Operating systems windows nt are. WNT: The True Story of Windows NT

WindowsNT

Windows NT is a line of operating systems (OS) produced by Microsoft Corporation and the name of the first versions of the OS.

Windows NT was developed after the termination of cooperation between Microsoft and IBM on OS / 2, developed separately from other operating systems of the Windows family (Windows 3.x and Windows 9x) and, unlike them, was positioned as a reliable solution for workstations (Windows NT Workstation) and servers (Windows NT Server). Windows NT gave rise to a family of operating systems that includes: Windows NT proper, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows 8, Windows Server 2012

Architectural modulesWindowsNT

The architecture of Windows NT is modular and consists of two main layers - user-mode components and kernel-mode components. Programs and subsystems running in user mode have restrictions on access to system resources. Kernel mode has unlimited access to system memory and external devices. The kernel of an NT system is called a hybrid kernel or a macrokernel. The architecture includes the kernel itself, the hardware abstraction layer (HAL), drivers, and a number of services (Executives) that operate in kernel mode (Kernel-mode drivers) or in user mode (User-mode drivers).

Windows NT user mode consists of subsystems that pass I/O requests to the appropriate kernel mode driver via an I/O manager. There are two subsystems at the user level: the environment subsystem (runs applications written for different operating systems) and the integrated subsystem (manages special system functions on behalf of the environment subsystem). Kernel mode has full access to the computer's hardware and system resources. And also prevents access to critical areas of the system by user services and applications.

Differences between Windows 2000 and NT 4.0

Some of the most significant improvements in Windows 2000 over Windows NT 4.0 are:

Support for the Active Directory directory service. The Active Directory back end comes with the Server, Advanced Server, and Datacenter Server editions, while the Professional edition provides full support for the client-side service.

IIS version 5.0. Compared to IIS 4.0, this version includes, among other things, version 3.0 of the ASP web programming system.

File system NTFS version 3.0 (also called NTFS 5.0 internally in Windows 2000 - NT 5.0). This version of NTFS for the first time introduced support for quotas, that is, restrictions on the maximum amount of stored files for each user.

Updated user interface, including Active Desktop based on Internet Explorer version 5 and thus similar to the interface of Windows 98. The color scheme has been redesigned.

Language integration: Previous versions of Windows were released in three versions - for European languages (single-byte characters, writing only from left to right), for Far Eastern languages (multi-byte characters) and for Middle Eastern languages (writing from right to left with contextual letter variants). Windows 2000 combines these features; all its localized versions are made on a single basis.

Encrypted file system EFS, with which you can encrypt files and folders.

Key FeaturesWindowsXP

The Microsoft Windows XP operating system is based on NT technology and is a direct successor to Windows 2000. However, all the best innovations included in Windows Me can be found in Windows XP. While maintaining high levels of reliability, security and performance, the system has become easier to learn, it has a lot of tools designed for individual home users.

The system is supplied in several versions, oriented to different application features. Microsoft Windows XP Home Edition is intended for individual users who most often work on a home computer. In this version, special emphasis is placed on working with pictures, audio and video. The version of Microsoft Windows XP Professional is intended, as the name implies, for professionals. This version is most commonly used in organizations. If you are doing complex work at home creating and editing images, modeling and construction, or any other complex work, then this version is also suitable for your home computer. The version of Microsoft Windows XP Server is designed to be installed on a server - a powerful computer that allows many users to work on a computer network. Working on local networks is outside the scope of this book, so the server version will not be considered here. The book describes the main version of the operating system - Windows XP Professional. Virtually no different version of Windows XP Home Edition. Minor differences will be highlighted.

It should be noted that in order to work effectively with the Windows XP operating system, a sufficiently powerful modern computer is required. First of all, the computer must have at least 128 megabytes of memory installed. It is better to install 256 megabytes so that the system runs faster. Any processor can be used, but not too old. If the processor clock speed is at least 300 megahertz, then it will do. Although it is better, of course, to use a processor with a frequency of more than one gigahertz. The hard drive must not only contain operating system files and temporary files, but also have enough free space, for example, to create an image of a CD before burning it. Really requires a disk size of at least two to three gigabytes. And if you consider that you need to install other programs on the disk and leave space for various documents, then a 10 gigabyte disk cannot be called too large.

The appearance of the system has changed a lot in the version of Windows XP. Buttons, icons, panels now look a little different. Even the Windows main menu has changed. The interface changes are the most significant since moving from Windows 3.1 to Windows 95. However, you can still use the old interface if you're used to it. Of particular note is the operation of programs in compatibility mode with previous versions of Windows. You can work with a program that was written for Windows 95 and does not work on Windows 2000. All versions of Windows XP have many new features. A much wider variety of devices are supported. The system allows you to easily and conveniently process videos, photos, pictures, music and songs. Now, with Windows XP, anyone can build a home network based on two or three computers, sharing files, folders, printer, fax, and Internet access.

When working with Windows XP, you do not need to install additional programs to write information to recordable and rewritable CDs. You can burn a CD directly from Windows Explorer. By the way, the conductor has changed a lot. In addition to supporting compressed folders, special folders for storing pictures, music and videos, a panel with commands has been added, the composition of which changes depending on the actions you perform.

A useful component of the system is the video editor. Now you can perform professional non-linear editing of your amateur films. It has become much easier to work with digital cameras and scanners. You do not need any additional program to enter a photo into a computer, slightly convert it and print it on a printer. The universal audio and video player now supports more formats and allows you to change its appearance. You can create your own sound files in the popular MP3 format. The media player also supports the playback of digital video discs (DVDs), allowing you to enjoy the highest quality picture and sound of today's movies. For entertainment, Windows XP includes several new games, some of which allow you to play online.

System protection has also been significantly improved. Now, if important system files are accidentally deleted, they will be automatically restored. It is possible to restore the system to an earlier state after installing new software and hardware. Improved support for Plug & Play technology allows you to connect many modern household appliances to your computer.

The means for working with the Internet have also been further developed. The help system has been significantly redesigned, the security system has been improved. Numerous changes have affected the means of administration and management of the work of many users in a local area network.

There are many other innovations in the system, which you will learn about as you read the book and get to know Windows XP. However, before you start working with the system, we recommend that you familiarize yourself with the basic concepts used in Windows XP. If you are familiar with previous versions of Windows, most of the concepts will be familiar to you.

WindowsVista

Windows Vista is an operating system of the Microsoft Windows NT family, a line of operating systems used on consumer personal computers. At the development stage, this operating system was codenamed "Longhorn".

In the Windows NT product line, Windows Vista is version number 6.0 (Windows 2000 is 5.0, Windows XP is 5.1, Windows Server 2003 is 5.2). The abbreviation "WinVI" is sometimes used to refer to "Windows Vista", which combines the name "Vista" and the version number written in Roman numerals.

Windows Vista, like Windows XP, is exclusively a client system. Microsoft also released a server version of Windows Vista, Windows Server 2008.

On November 30, 2006, Microsoft officially released Windows Vista and Office 2007 to corporate customers. On January 30, 2007, sales of the system began in the CIS for ordinary users.

According to web analytics from W3Schools, as of October 2012, Windows Vista's market share is ▼ 3.0%; this value peaked at 18.6% in October 2009.

Windows 7

Windows 7 is the operating system of the Windows NT family, following Windows Vista. The next system in the Windows 8 line after Windows 7. In the Windows NT line, the system has version number 6.1 (Windows 2000 - 5.0, Windows XP - 5.1, Windows Server 2003 - 5.2, Windows Vista and Windows Server 2008 - 6.0). The server version is Windows Server 2008 R2, the version for integrated systems (built from Windows components) is Windows Embedded Standard 2011 (Quebec), the mobile version is Windows Embedded Compact 2011 (Chelan, Windows CE 7.0).

The operating system went on sale on October 22, 2009, less than three years after the release of the previous operating system, Windows Vista. Volume Licensing partners and customers were granted access to RTM on July 24, 2009. On the Internet, the original installation images of the final version of the system have been available since July 21, 2009.

According to web analytics from W3Schools, as of October 2012, Windows 7's share of the world's Internet operating systems was ▲ 56.8%. According to this criterion, it is in first place, surpassing the previous leader in August 2011 - Windows XP.

File systemNTFS

NTFS (from the English New Technology File System - “new technology file system”) is a standard file system for the Microsoft Windows NT family of operating systems.

The HPFS file system was first used for the OS/2 1.2 operating system to provide access to the large disks that were on the market at the time. In addition, there is a need to expand the existing naming system, improve organization and security to meet the growing needs of the network server market. The HPFS file system supports the FAT directory structure and adds sorting of files by name. The file name can contain up to 254 double-byte characters. A file is made up of "data" and special attributes, which creates additional opportunities to support other types of filenames and improve security. In addition, the smallest block for data storage is now equal to the size of the physical sector (512 bytes), which helps to reduce wasted disk space.

NTFS has replaced the FAT file system used in MS-DOS and Microsoft Windows. NTFS maintains a metadata system and uses specialized data structures to store information about files to improve performance, reliability, and disk space efficiency. NTFS stores information about files in the Master File Table (MFT). NTFS has built-in capabilities to restrict access to data for different users and user groups (access control lists - Access Control Lists (ACL)), as well as assign quotas (restrictions on the maximum amount of disk space occupied by certain users). NTFS uses the USN journaling system to improve file system reliability.

NTFS is based on the HPFS (High Performance File System) file system developed by Microsoft and IBM for the OS/2 operating system. But, having received such undoubtedly useful innovations as quoting, journaling, access control and auditing, it has largely lost [source not specified 242 days] the very high performance of file operations inherent in its ancestor (HPFS).

There are several versions of NTFS: v1.2 is used in Windows NT 3.51 and Windows NT 4.0, v3.0 comes with Windows 2000, v3.1 comes with Windows XP, Windows Server 2003, Windows Server 2003 R2, Windows Vista, Windows 7 and Windows Server 2008, Windows Server 2008 R2.

The file system specifications are closed. This creates certain difficulties when implementing its support in third-party products that do not belong to Microsoft - in particular, developers of drivers for free operating systems have to reverse engineer the system.

Entries in the directory of the HPFS file system contain more information than in FAT. Along with file attributes, information about creation and modification, as well as the date and time of access, is stored here. The entries in the HPFS directory do not point to the first cluster of the file, but to the FNODE. FNODE can contain file data, pointers to file data, or other structures pointing to file data. HPFS tries to place file data in contiguous sectors whenever possible. This leads to an increase in the speed of sequential processing of the file. HPFS divides the disk into blocks of 8 MB each and always tries to write the file within the same block. For each block, 2 KB is reserved for the allocation table, which contains information about the written and free sectors within the block. Blocking leads to better performance, since the disk head to determine where to save the file must return not to the logical beginning of the disk (usually this is cylinder zero), but to the allocation table of the nearest block. In addition, the HPFS file system contains two unique data objects.

Development history

The development of Windows NT under the working title "NT OS / 2" was started in November 1988 by a group of specialists led by David Cutler (Eng. Dave Cutler ), who moved to Microsoft from DEC, where they developed VAX and VMS. The work went hand in hand with the development of IBM's own operating system, OS/2 2.0, which was finally released in April 1992. At the same time, Microsoft continued to develop its operating systems of the DOS and Windows families, which are distinguished by lower requirements for computer resources than IBM OS / 2. After Windows 3.0 was released in May 1990, Microsoft decided to add a Windows API compatible programming interface (API) to NT OS/2. This decision caused serious friction between Microsoft and IBM, which ended in a break in collaboration. IBM continued to develop OS/2 on its own, while Microsoft began working on the system, which was eventually released under the name Windows NT. Although it didn't immediately become popular like DOS, Windows 3.x, or Windows 9.x, from a marketing standpoint, Windows NT proved to be significantly more successful than OS/2.

It should be noted that OS / 2 APIs and then POSIX were originally planned as programming interfaces for NT OS, support for the Windows API was added last. In addition, Intel i860 and then MIPS were originally planned as a hardware platform for NT, support for Intel x86 was also added later. Then, during the evolution of this OS, support for both originally planned software interfaces and both originally planned hardware platforms disappeared. There was not even a single release version of this OS for the i860, although it was from the code name of this processor that N10(N Ten) is the name of the NT OS itself. Microsoft now stands for NT as new technology. And as an alternative to the POSIX subsystem, Microsoft began offering the Microsoft Windows Services for UNIX package.

To develop the NT OS, Microsoft invited a group of specialists from DEC, led by David Cutler ( English) with experience building multitasking operating systems such as VAX/VMS and RSX-11. Some similarities noted between the internal architectures of Windows NT and the VMS family of operating systems gave grounds to accuse newly hired Microsoft employees of stealing DEC intellectual property. The resulting conflict was resolved amicably: DEC recognized Microsoft's ownership of the technologies underlying Windows NT, and Microsoft created and maintained a version of Windows NT for the DEC Alpha architecture.

Despite their common roots, compatibility between Windows NT and OS/2 has decreased with each new release of this OS. Support for the OS/2 2.0 API, although planned for NT, was never completed; Windows NT 4.0 removed support for the HPFS file system, and Windows XP removed the Software Support Subsystem for OS/2 1.x.

Versions

Name ( code name), options	version number	first edition	latest release /
Windows NT 3.1	3.1.528	July 27	SP3 (November 10)
Windows NT 3.1	Workstation, Advanced Server
Windows NT 3.5 ( Daytona)	3.5.807	September 21	SP3 (June 21)
Windows NT 3.5 ( Daytona)	Workstation, Server
Windows NT 3.51 ( Tukwila)	3.51.1057	May 30	SP5 (September 19)
Windows NT 3.51 ( Tukwila)	Workstation, Server
Windows NT 4.0 ( Indy)	4.0.1381	July 29	SP6a (November 30)
Windows NT 4.0 ( Indy)	Workstation, Server, Server Enterprise ( Granite), Terminal Server ( Hydra), Embedded ( Impala)
Windows 2000 ( Cairo)	5.0.2195	February 17	SP4 (June 26)
Windows 2000 ( Cairo)	Professional, Server, Advanced Server, Datacenter Server
Windows XP ( Whistler)	5.1.2600	the 25th of October	SP3 (May 6)
Windows XP ( Whistler)	Home, Professional, 64-bit, Media Center ( eHome), Tablet PC, Starter, Embedded ( Mantis), N; Windows Fundamentals for Legacy PCs ( Eiger)
Windows Server 2003 ( Whistler Server, Windows .NET Server)	5.2.3790	April 24	SP2 (May 13)
	Standard, Enterprise, Datacenter, Web, Small Business Server ( bobcat), Compute Cluster Server, Storage Server; Windows XP Professional x64
Windows Vista ( Longhorn)	6.0.6000	January 30	SP2 (May 25)
Windows Vista ( Longhorn)	Starter, Home Basic, Home Premium, Business, Enterprise, Ultimate, N Home Basic, N Business; x64 variants of all but Starter
Windows Server 2008 ( Longhorn Server)	6.0.6001	February 27	SP2 (May 27)
Windows Server 2008 ( Longhorn Server)	Standard, Enterprise, Datacenter, HPC, Web, Storage, Small Business ( Cougar), Essential Business ( Centro), Itanium; x64 variants of all but HPC
Windows 7 ( blackcomb, Vienna)	6.1.7600	22 of October	SP1 (KB976932) (February 22)
Windows 7 ( blackcomb, Vienna)	Starter, Home Basic, Home Premium, Professional, Enterprise, Ultimate, Windows 7 N, Windows 7 E; x64 versions of all but Starter
Windows Server 2008 R2	6.1.7600	22 of October	SP1 (KB976932) (February 22)
Windows Server 2008 R2	Standard, Enterprise, Datacenter, HPC, Web, Storage, Small Business, Itanium; all versions are 64-bit only
Windows 8	6.2.9200	October 26	Pro (October 26)
Windows 8	Windows 8, Windows 8 RT, Professional, Professional N, Professional WMC, Enterprise, Enterprise N; x64 variants of all but Windows RT
Windows Server 2012	6.2.9200	October 26	RTM (August 1)
Windows Server 2012	Standard, Datacenter, Storage; all versions are 64-bit only

Internal architecture

Kernel Components

User Mode Components

The user interface subsystem in Windows NT implements a windowed interface, similar to that of previous versions of Windows. Two types of objects in this subsystem that were not present in 16-bit versions of Windows and in Windows 9x are window stations and desktops. A window station corresponds to a single Windows NT user session - for example, when connecting via Remote Desktop Service, a new window station is created. Each running process belongs to one of the window stations; services, except those marked as capable of interacting with the desktop, run in separate, invisible window stations.

Each window station has its own clipboard, a set of global atoms (used for DDE operations), and a set of desktops. The desktop is the context for all global operations of the user interface subsystem, such as installing hooks and broadcasting messages. Each running thread belongs to one of the desktops - the one where the windows served by it are located; in particular, a single thread cannot create multiple windows belonging to different desktops. One of the desktops can be active (visible to the user and able to respond to his actions), the rest of the desktops are hidden. The ability to create multiple desktops for a single session and switch between them has not yet been provided by standard Windows user interface tools, although there are third-party programs that provide access to this functionality.

Window stations and desktops are the only objects in the Windows NT user interface subsystem that can be assigned permissions. Remaining object types - window and menu- give full access to any process that is with them in the same window station. Therefore, Windows NT services run in separate window stations by default: they run with elevated privileges, and allowing user processes to manipulate service windows indefinitely could lead to crashes and/or security issues.

Software interfaces

Native API

Windows NT provides several sets of APIs for application programs. The main one is the so-called "native" API ( NT Native API) implemented in the dynamic-link library ntdll.dll and consisting of two parts: NT kernel system calls (functions with the Nt and Zw prefixes that transfer execution to the ntoskrnl.exe kernel functions with the same names) and functions implemented in user mode (with the prefix RTL). Some of the functions of the second group use system calls internally; the rest consist entirely of unprivileged code, and can be called not only from user-mode code, but also from drivers. In addition to the Native API functions, ntdll also includes functions from the C Standard Library.

The official documentation for the Native API is very sparse, but the community of enthusiasts managed to collect quite a lot of information about this interface through trial and error. In particular, in February 2000, Gary Nebbet's book " Basic Windows NT/2000 API Reference» (ISBN 1-57870-199-6); in 2002 it was translated into Russian (ISBN 5-8459-0238-X). The source of information about the Native API is the Windows DDK, which describes some of the kernel functions available through the Native API, as well as the study of Windows code (reverse engineering) - through disassembly, either using leaked Windows 2000 sources, or using the original Windows 2003 texts available through the Windows Research Kernel program.

Programs that run before the subsystems that run the rest of the Windows NT APIs are loaded are restricted to using the Native API . For example, the autochk program, which checks disks when the OS boots after an incorrect shutdown, uses only the Native API.

Win32 API

Most often, applications for Windows NT use the Win32 API, an interface created on the basis of the API of Windows 3.1, which allows you to recompile existing programs for 16-bit versions of Windows with minimal changes to the source code. The compatibility of the Win32 API and the 16-bit Windows API is so great that 32-bit and 16-bit applications can freely exchange messages, work with each other's windows, etc. In addition to supporting the functions of the existing Windows API, a number of new features, including support for console programs, multithreading, and synchronization objects such as mutexes and semaphores. Documentation for the Win32 API is included with the Microsoft Platform SDK and is available from the .

The Win32 API support libraries are mostly named the same as the Windows 3.x system libraries, with the suffix 32 added: these are the libraries kernel32 , advapi32 , gdi32 , user32 , comctl32 , comdlg32 , shell32 and a number of others. Win32 API functions can either independently implement the required functionality in user mode, or call the Native API functions described above, or access the csrss subsystem through the LPC mechanism ( English), or make a system call to the win32k library, which implements kernel-mode support for the Win32 API. The four options listed can also be combined in any combination: for example, the Win32 API function WriteFile calls the Native API function NtWriteFile to write to a disk file, and calls the appropriate csrss function to output to the console.

Win32 API support is included in the Windows 9x family of operating systems; it can also be added to Windows 3.1x by installing the Win32s package. To facilitate the porting of existing Windows applications that use MBCS encodings to represent strings, all Win32 API functions that take strings as parameters have been created in two versions: functions with an A suffix ( ANSI) accept MBCS strings, while functions with a W suffix ( wide) accept UTF-16 encoded strings. On Win32s and Windows 9x, only A-functions are supported, while on Windows NT, where all strings inside the OS are stored exclusively in UTF-16, each A-function simply converts its string parameters to Unicode and calls the W version of the same function. The H-files of the library also define function names without a suffix, and the use of the A- or W-version of functions is determined by compilation options, and in Delphi modules before 2010, for example, they are tightly tied to options with the A suffix. It is important to note that that most of the new features introduced in Windows 2000 or later in the Windows NT family exist only in the Unicode version, because the problem of ensuring compatibility with older programs and with Windows 9x is no longer as acute as it used to be.

POSIX and OS/2

The first release of Windows NT 4 supported four platforms (x86, Alpha, MIPS, and PowerPC), but support for less common platforms was reduced as service packs were released: MIPS support was removed from SP1, and PowerPC support from SP3. Recent releases of Windows NT 4 only supported x86 and Alpha; although Alpha support was planned for inclusion in Windows 2000, it was dropped from the RC2 release. As a result, the only platform supported on Windows 2000 was x86.

Support for 64-bit processors was first implemented in Windows XP for IA-64, the Intel Itanium processor architecture. Based on the 64-bit version of Windows XP, 64-bit server versions of Windows 2000 were also created; support for the Itanium processor was later added to some versions of Windows Server 2003. The second 64-bit architecture supported in the Windows NT family of operating systems was the x86-64 architecture created by AMD, later implemented in Intel processors under the name EM64T. Windows Server 2003 SP1 x64 and Windows XP Professional x64 were released at the same time, which are server and desktop versions of the same version of Windows - in particular, the same updates apply to these editions. Since 2005, Microsoft has made the decision to end support for IA-64.; The latest version of Windows NT that fully supports Itanium is Windows NT 5.2 (XP Professional 64-bit Edition and Server 2003). However, for more expensive (and therefore more difficult to upgrade) servers, special versions of Windows Server 2008 and Windows Server 2008 R2 were released, and Windows Server 2012 no longer received IA-64 support.

Notes

In an effort to ensure compatibility (compatible) of the new operating system, the developers of Windows NT retained the familiar Windows interface and implemented support for existing file systems (such as FAT) and various applications (written for MS - Dos, OS / 2 1.x, Windows 3.x and POSIX). Developers also included tools for working with various networking tools in Windows NT.

System portability has been achieved, which can now run on both CISC and RISC processors. CISC includes Intel-compatible 80386 and higher processors; RISCs are represented by systems with MIPS R4000, Digital Alpha AXP and Pentium P54 series and higher processors .

Scalability means that Windows NT is not tied to a single-processor computer architecture, but is able to take full advantage of the possibilities provided by symmetrical multiprocessor systems. Currently, Windows NT can run on computers with between 1 and 32 processors. In addition, as user tasks become more complex and requirements for the computing environment expand, Windows NT makes it easy to

add more powerful and productive servers and workstations to the corporate network. Additional benefits are provided by the use of a single development environment for both servers and workstations.

Windows NT has a uniform security system (security) that meets the specifications of the US government and complies with the B2 security standard. In a corporate environment, critical applications are provided with a completely isolated environment.

Distributed processing means that Windows NT has networking capabilities built into the system. Windows NT also allows communication with various types of host computers through support for a variety of transport protocols and the use of high-level client-server facilities, including named pipes, remote procedure calls (RPCs) and Windows sockets.

Reliability and robustness provide architectural features that protect application programs from being corrupted by each other and by the operating system. Windows NT uses fault-tolerant structured exception handling at all architectural levels, which includes a recoverable NTFS file system and provides protection through built-in security and advanced memory management techniques.

Localization capabilities (allocation) provide the means to work in many countries of the world in national languages, which is achieved by using the ISO Unicod standard (developed by the international organization for standardization).

Windows NT concepts

The Windows NT operating system is implemented in two flavors: Windows NT Server and Windows NT Workstation. Windows NT Server 4.0 is a network operating system with Internet applications, file and print services, remote access service, built-in router, file indexing, and network management. The second variant of Windows NT, Windows NT Workstation 4.0, is a lot like NT Server, but it's optimized as a workstation operating system. In terms of architecture and features, Windows NT Server is a superset of Windows NT Workstation and includes all the features of the latter. Further, in cases where it is not indicated which OS is meant, the comments refer to both.

Origins of Windows NT

The beginning of work on the creation of Windows NT falls on the end of the 88th year. Microsoft has appointed David Cutler to lead a new software project: New Technology (NT) OS development. David Cutler was DEC's principal consultant and worked for the firm for 17 years developing OS and compilers: VAX/VMS, OS for MicroVAX I, OS RSX-11M, VAX PL/1 compilers, VAX C.

Windows NT was first developed as a lightweight version of OS/2 (OS/2 Lite) that could run on less powerful machines by truncating some features. However, over time, seeing how successful Windows 3.0 was received by consumers, Microsoft refocused and began to develop an improved version of Windows 3.1. Microsoft's new strategy was to create a single family of Windows-based operating systems that would cover many types of computers, from the smallest laptops to the largest multiprocessor workstations.

Windows NT, as the next generation of Windows systems has been called, is the highest level in the hierarchy of the Windows family. This operating system, which originally supported the familiar graphical user interface (GUI) of the Windows user, was Microsoft's first fully 32-bit operating system. The Win32 API - a programming interface for developing new applications - made available to applications improved OS features, such as multithreaded processes, synchronization, security, I / O, object management.

The conceptual advantages of Windows NT over the MS-DOS/Windows 3.1 pairing were clear. Its 32-bit basis, together with true multitasking and multithreading, greatly increased the potential of the system.

The first operating systems of the NT family, Windows NT 3.1 and Windows NT Advanced Server 3.1, appeared in July 1993. The code name for the next version of Windows NT 3.5, Daytona, which is the same as the name of the Florida highway, may have indicated that its main advantage is speed. Indeed, the performance of version 3.5 increased by 1.5 times compared to version 3.1, and after its introduction, many corporate users who rejected version 3.1 for one reason or another, reconsidered their attitude towards the NT line: in 1995, the share of Windows NT in their sector of the market increased by 2 times and amounted to 15%.

Features of Windows NT 4.0 version

In August 1996, the next version of Windows NT 4.0 was released. This next version of Windows NT was originally supposed to be numbered 3.52, but it was given the number 4.0, which was previously mentioned in the computer press in connection with another upcoming version of Windows NT codenamed Cairo. Perhaps this indicates that this latest version (Windows NT 4.0) has so many important new features that require more significant encoding changes. The innovations made in Windows NT Server 4.0 are mainly related to the improvement of the user interface, the expansion of Internet support, the introduction of new and modernization of existing administrative tools, and the improvement of system performance.

Many significant changes were made in Windows NT 4.0, among which the following are the most significant:

interface implementation in the style of Windows 95;

orientation towards the Internet and intranet;

architectural changes that allowed to dramatically increase the performance of graphic operations;

modification of means of interaction with NetWare - Gateway and NCP client now support NDS;

support for multiprotocol routing;

the appearance in Windows NT 4.0 of an emulator of Intel's processors for RISC platforms.

There are other improvements in version 4.0. For example, Windows NT Server 4.0 greatly improves scalability over Windows NT Server 3.51, allowing for significantly faster performance on machines with 4 processors, as well as linear performance gains on machines with eight or more processors.

The performance of Windows NT Server 4.0 when operating as a file server also increased significantly and exceeded the performance of Windows NT Server 3.51, according to some reports, more than 2 times.

The new Windows NT administrative tools can run remotely on Windows 95 clients. In addition, Windows NT Server provides a remote boot service for Windows 95 clients. (This is useful for diskless workstations.)

Windows NT 4.0 features a new Windows 95-style graphical user interface. Although some users may not like this change, Microsoft is restoring the "one-stop-shop" principle that was originally considered one of Windows NT's strengths. On a network with client stations running Windows 95 or Windows NT (or on a mixed network that includes such stations), Windows NT Server administrators can perform their functions using the same interface as workstation users.

Aside from external changes, the GUI upgrade hasn't had much of an impact on network management methods. The basic Windows NT Server administrator tools remain the same. The User Manager for Domains, Server Manager, Disk Administrator, Event Viewer, Performance Monitor, DHCP Manager, WINS Manager, Network Client Administrator, License Manager, and Migration Tool for NetWare have not changed significantly. Remote Access Administrator hasn't changed either, but has now been moved from a separate folder to the Administrative Tools menu. The new System Policy Editor, which is compatible with both Windows NT and Windows 95, has replaced the User Profile Editor you've seen since Windows NT Server 3.x. Version 4.0 includes four additions: Administrative Wizards, the already mentioned System Policy Editor, as well as an advanced Windows NT Diagnostics tool and Network Monitor (a network monitoring program previously only included with the Microsoft Systems Management Server product).

Administrative Wizards allow you to easily perform step-by-step actions such as creating user accounts, managing user groups, controlling access to files and directories, installing a new printer, installing and uninstalling programs, connecting a modem, preparing installation diskette packages for new customers and monitoring compliance with license agreements for installed programs. All this will be useful for those administrators who find that, despite the presence of a graphical interface, Windows NT management tools are still complicated.

Windows NT 4.0 has several useful system monitoring components borrowed from Microsoft's Systems Management Server. The main application is the Performance Monitor tool that graphically monitors selected system events. In particular, the Performance Monitor can be used to get graphs of CPU utilization, total NIC I/O, and the number of bytes transferred over HTTP.

Another application, the Monitor Tool, is also capable of capturing and monitoring network traffic coming and going from a computer under NT. A monitoring scenario (for example, a description of what protocol frames you want to monitor, what traffic characteristics to measure, from which workstations or users) can be saved and reused if necessary.

The set of wizards is still far from functional completeness. For example, it does not have a program that would move the user's budget from one domain to another, that is, would perform procedures related to the need to delete one account and create another.

Other innovations in Windows NT Server 4.0 are related mainly to the Internet and the intranet. An important place among them is occupied by the following software components included in the delivery set:

Internet Information Server (IIS) version 2.0 is a Microsoft product that provides Web, ftp and gopher server services, the capabilities of Internet Information Server are comparable, and in a number of tests they surpass the similar popular product Server Netscape. Microsoft Internet Information Server 2.0 is the fastest Web server for Windows NT Server - it outperforms its 1.0 predecessor by 40 percent;

Object model of distributed components - Distributed Component Object Model (DCOM), which provides secure communication between components over the Internet;

DNS / WINS Server, which makes it easy to find the necessary Web sites on the Internet or intranets;

PPTP technology (point-to-point tunneling protocol), which extends the functionality of the Windows NT Server (RAS) remote access server and provides the ability to create private networks on the Internet;

FrontPage, which lets you create Web pages from a variety of templates, validate links, and generally manage the Web sites you create;

index server Microsoft Search Server, which makes it easy to find information on distributed intranet servers within any documents, including those created in Microsoft Office.

Two Internet-facing features of the new system are of particular interest to administrators. The first is the DNS name service. It allows the use of DNS names, but only supports static addressing. To remove this limitation, Microsoft offers DNS and WINS integration, calling this combination "true dynamic DNS". Now, when a WINS client needs to determine the IP address that corresponds to the symbolic NetBIOS name, it first consults the WINS database and then the DNS itself. Thus, both dynamically recognized WINS names and static DNS names can be used equally in the system.

In addition, Windows NT 4.0 includes a Web-based administration utility that provides access to Windows NT administration tools from any Web browser. For security reasons, remote administration should use Web browsers that can log the user directly to the Windows NT server (ie, such as Internet Explorer) or support SSL.

One of the improvements is due to the fact that the increasing role of the Internet "and client-server systems is leading to an increase in the number of mobile users. Microsoft has improved RAS in this regard (improved ISDN support) and provided tools for securely working with RAS over the Internet. RAS implements protocols PPTP (creates encrypted traffic over the Internet) and Multilink PPP (allows you to combine several channels into one) Clients can be Windows NT 4.0 Workstation or Windows 95.

The Distributed Component Object Model is another key addition to Windows NT Server 4.0. The Object Linking Model (COM) allows software developers to create applications that are made up of individual components. The Distributed Model (DCOM) in Windows NT Server 4.0 extends COM in a way that allows individual components to communicate over the Internet. DCOM is a growing Internet standard published according to the format defined in the RFC 1543 specifications.

In the development of Windows NT 4.0, Microsoft decided to sacrifice stability for performance. To this end, architectural changes have been made: the window manager and GDI libraries, as well as graphics adapter drivers, have been moved from user mode to kernel mode. This change marks a departure from the concept of a microkernel adopted in previous versions of Windows NT 3.x.

Moving the graphics library and drivers to the kernel improves the performance of graphics I/O. These changes especially affected the speed of Win32 applications, while Windows-16 applications and DOS graphical applications work in much the same way as in version 3.5.

At the same time, the described changes make the operating system, in principle, less reliable. Indeed, since graphics adapter software is usually developed by the hardware manufacturers, and this software often changes (along with the hardware), it is difficult to expect from it the reliability that is required for operating system modules.

New Features in Windows NT 5.0

Late 1997 is expected to see Windows NT 5.0, an improved version of Windows NT. It will not only be a fully 32-bit system, but also a fully object-oriented system. The basis of Windows NT 5.0 is an object-oriented file system, implemented on the basis of the OLE 2.0 standard, which allows you to store objects, not files. The object-oriented approach makes it possible to ensure the correctness of multiple copies of data, such as documents, spreadsheets, applications, and other types of information, stored on different network machines at the lowest cost.

Windows NT 5.0 promises a lot, and innovations will primarily affect the following subsystems:

Active Directory is a global directory service that develops a 2-tier approach to DNS name resolution. Active Directory contains information not only about files, but also about objects of other types, for example:

Computer name, IP address, Username, password, mail address, Application name, computer, version, permissions.

Distributed File System (Dfs) - distributed file system (freely available at www.microsoft.com). The directories of this file system, located on different servers, are mounted in a common tree starting on the root server with the root share name. Different subtrees of a single share can consist of not only Microsoft file systems, but also Novell NCP and Sun NFS file systems. Some branches of the distributed file system can be transparently replicated at the discretion of the administrator.

Distributed Component Object Model (DCOM) - program objects (ActiveX or others) can be distributed across network servers and called by applications from any computer. Information about the location of objects is registered in Active Directory.

Security features: Windows NT 5.0 will check document access rights using Kerberos or electronic signature, and transfer documents over the network will be implemented using encryption.

Hardware Requirements

There are differing opinions about whether the hardware requirements of Windows NT are high. Some feel that they are too high, and some consider these requirements quite acceptable. It all depends on what tools or what fleet of computer equipment is available to a potential consumer of Windows NT, and what tasks he faces.

To run Windows NT Workstation 4.0, the computer must have at least an i486 processor (in this version of the system, Microsoft has refused any support for i386 processors), at least 12 MB of RAM and 108 MB of disk space. And although this OS is fully functional on computers with less than 16 MB of RAM, it is recommended to install it if you have RAM that is twice the minimum capacity, i.e. 24 MB, and free disk space is at least 216 MB. You can run Windows NT Workstation 4.0 on a system with fewer resources, but then the user is unlikely to be satisfied with its performance.

For Windows NT Server 4.0, Microsoft specifies the following hardware requirements: i486 or faster processor, 16 MB of RAM, and at least 148 MB of contiguous free disk space. To get acquainted with the functionality of the system, this may be enough, but for "industrial" use, these minimum requirements are clearly not enough. A server with a low or medium load (defined by the number of users served) requires 32 MB of RAM and a minimum of 1 GB hard drive.

A complete list of hardware that has been tested for compatibility with Windows NT is contained in the documentation for the system and on the server. www.microsoft.com.

Uses for Windows NT

With high performance, stability, advanced security features, and having a wide range of basic system functions in its arsenal, Windows NT Server can be used in various areas, and, above all, it can be used as a server in a corporate network. Here, its ability to act as a domain controller is very useful, which allows you to structure the network and thereby simplify administration and management tasks. It is also used as a file server, print server, application server, remote access server and communication server (software router).

Clients on a Windows NT Server network can be computers with different operating systems installed on them. Supported as standard: Windows NT Workstation, MS-DOS, OS/2, Windows for Workgroups, Windows 95, UNIX clones, Macintosh. Core clients are included as standard with Windows NT Server.

Windows NT Server is a powerful platform for complex network applications, especially those built using client-server technology. Combined with BackOffice servers, it can meet a very wide range of corporate user needs. For example, a Microsoft SQL Server database server can run under Windows NT Server, as well as database servers from other well-known companies, such as Oracle and Sybase, Adabas and InterBase database servers.

On the Windows NT Server platform, a powerful administration system Microsoft System Management Server can be installed, the functions of which are inventory of the hardware and software configuration of network computers, automatic installation of software products on workstations, remote control of any computer and network monitoring.

Windows NT Server can be used as a communication server with IBM mainframes and IBM AS400 systems. For this, a special Microsoft SNA Server product has been created, which makes it easy to combine IBM PC-compatible workstations and powerful mainframes in one network. SNA Sever is a gateway that allows workstation access to both LAN and mainframe servers without the need for two network cards or multiple network protocol stacks. This results in a reduction in hardware cost and a reduction in the amount of RAM required. Providing transparent access to mainframes, SNA Server, integrated with NT Server security, provides host access authorization. SNA Server can work with any of the protocols supported by NT Server: IPX/SPX, TCP/IP, or NetBEUI.

Windows NT Server is the platform for Microsoft Exchange, a new high-performance collaboration suite built on top of a mail server.

Finally, the latest version of Windows NT 4.0 is a solid platform for Internet-oriented applications: Web servers, Web browsers, information retrieval systems, Internet e-commerce systems.

The Windows NT Workstation operating system is positioned primarily as a client in Windows NT Server networks, as well as in NetWare, Unix, Vines networks. On NetWare networks, Windows NT workstations fill a well-known gap - the lack of a good application server. A computer with Windows NT installed on it can also be a workstation in peer-to-peer networks, performing the functions of both a client and a server at the same time. Windows NT Workstation can be used as a stand-alone operating system when increased performance or privacy is needed, or when implementing complex graphical applications such as computer-aided design systems.

In this article, we will look at the types of Windows NT operating systems. Windows NT is not Windows2000 or anything else. This is a series, or rather a platform, on the basis of which the OS is being developed. Almost the entire Windows family is based on this platform. In addition to NT, there is also the 9x platform, which includes Windows95, Windows98 and WindowsME.

Due to the fact that there were concerns about the incorrect operation of programs written with older versions of the OS in mind, the 10th version of the operating system was released immediately after the eighth. Otherwise, 9 in the version could be interpreted by the program as an operating system of the 9 series. Details about what NT is - in this article.

Windows NT(colloquially just NT) is a line of operating systems (OS) produced by Microsoft Corporation and the name of the first versions of the OS. Windows NT was developed after the termination of cooperation between Microsoft and IBM on OS / 2, developed separately from other operating systems of the Windows family (Windows 3.x and Windows 9x).

Unlike Windows 3.x and Windows 9x, Windows NT was positioned as a reliable solution for workstations (Windows NT Workstation) and servers (Windows NT Server). Windows NT gave rise to a family of operating systems that includes: Windows NT itself, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows 8. Information from the article Windows NT, Wikipedia.

Windows OS Name	NT version number
Windows NT 4.0	4.0.1381
5.0.2195
Windows XP	5.1.2600
6.0.6000
Windows 7	6.1.7600

The number that comes after the letters NT- this is the serial number of the development of the OS based on NT. Windows 7 (Windows NT6.1), the seventh NT-based development, is now out. Vista - NT6.0, XP - NT5.1, Windows2000 - NT5.0. Win2K is just a physical interpretation of the number (2K=2000). Windows NT is a whole family of operating systems. You often encounter this when downloading installation and configuration manuals or device drivers.

Since the days of Windows95, the interface of the operating system has not fundamentally changed much. Of course, it has become better, more perfect and more convenient, many new functions have appeared. But a person who worked on Windows2000 will easily get used to subsequent versions of Windows (if we talk about the system interface as a whole). Technically, the systems differ from each other, the ways of solving user tasks on different systems also differ.

In general, if we describe this family of operating systems, then we can say that the history of Windows is divided into 2 parts - before the release of Windows Vista and after. Microsoft developers did not bring anything fundamentally new (except for visual effects) to the interface of this version of their OS, however, the system core was completely rewritten.

Due to the new kernel, compatibility was lost with older programs (whose development stopped before the release of Vista) and older device drivers. This largely explains the notoriety and unpopularity of this version of Windows. In Windows7, developers took into account the errors, software and hardware manufacturers already had the opportunity to release software and hardware taking into account the new requirements of the OS, but most of the old programs and old equipment are no longer supported by this operating system.

Windows Version Compatibility

To get around (many industrial programs don't work on Windows7), Windows7 Professional, Enterprise and Ultimate editions have the ability to run programs from XP-Mode. XP-Mode is a virtual machine and an image of a licensed WindowsXP. True, the graphic emulation capabilities are at the level of S3 Trio64 without 3D support, that is, the very minimum.

Roots

It all started in 1975 when Digital Equipment Corporation initiated the development of its 32-bit VAX platform.

The project was led by Cutler, who had already built a reputation for being a tough systems engineer by building the RSX-11M for the famous PDP-11 minicomputers. In 1977, the VAX-11/780 machine and its operating system, VMS 1.0, were announced. Four years later, Cutler was insanely tired of "attributing" numbers after the same three-letter prefix, and he decided to leave Digital. However, the functionaries of the corporation turned out to be more cunning: since a talented developer cannot be kept in the bosom of the organization, they decided to imitate the atmosphere of a startup and free creativity. An autonomous division in Seattle was created, and Cutler was allowed to recruit the required number of personnel (about 200 people) directly from Digital employees. The new structure took up the design of the processor architecture and operating system, codenamed Prism.

Diagram of the development of operating systems of the Windows NT family

The "happy moment" did not last long, the big bosses failed to bring the work they had begun to its logical conclusion, and in 1988 Cutler, along with his 200 engineers and programmers, found himself on free bread. But the well-known developer was not left out of work: at that time, a decision was ripe in the head of Bill Gates about the need to create a server OS that competes with Unix clones. Only to get David Cutler, the future Microsoft CEO agreed to hire 20 ex-Digital engineers of his choice. In November 1988, a team of five Digital people and one Microsoft programmer set to work.

The task was to write an OS for the new Intel i860 RISC processor, codenamed N-Ten. From here, by the way, the abbreviation NT arose, later interpreted by Microsoft marketers as New Technology. Already in December 1988, the first fragments of the system were ready. The catch was that the i860 only existed on paper, so the code had to be tested on a software emulator. Development was carried out on "toy", by today's standards, Intel 386 25 MHz machines with 13 MB of RAM and 110 MB hard drives.

The microkernel architecture that underpinned NT from the very beginning became crucial when it was discovered in 1989 that the hardware i860 was not capable of efficiently executing written code. I had to switch to MIPS R3000 and then to the standard Intel 386 processor, which was done in less than a year by a team that increased to 28 engineers.

In 1990, the most important event that became a key event in the fate of NT took place - the release and dizzying success of Windows 3.0. In fact, it was Microsoft's first multi-tasking OS with a decent graphical interface that allowed real work to be done. It was the borrowing of this interface and API that predetermined the future of NT. Initially, the server OS was supposed to be a remake of the joint OS / 2 project with IBM and, accordingly, function with existing OS / 2 applications. However, the third version of Windows appeared just in time: Redmond abandoned his allies and refocused the NT development team on the design of the Win32 API, made in the "image and likeness" of the Win16 interface. This provided much-needed continuity that made it easier to port applications from the desktop to the server platform.

The NT development team, which had by then become Windows NT, began to grow rapidly, and soon had about 300 people working in it. The abandonment of OS/2 orientation led to serious problems in the relationship between Microsoft and IBM. There were no official statements, just at one of the inter-corporate presentations, IBM employees found in confusion that the OS created had nothing to do with the brainchild of their company. Nevertheless, Windows NT 3.1 (numbering was "adjusted" to the current version of 16-bit Windows that existed at that time) included support for DOS, Win16, POSIX and OS / 2 APIs, including. In July 1993, a new server system from Microsoft came out and started its journey.

Then things went smoothly: in September 1994, Windows NT 3.5 was released. The previous version was prepared in a feverish rush, everything had to be coded from scratch, and a lot of features remained unimplemented. Now it's time to think about efficiency, speed and ... organizing some kind of interaction with networks built on NetWare - the absolute leader of that time, dominating the local area network market. If in those years they were so attentive to the issues of regulation of monopolies, as is done today, perhaps it would be enough to write the appropriate slander to the appropriate authority. Alas, Microsoft had to deal with the situation on its own. Novell hesitated whether or not to provide client support for Windows NT. Redmond couldn't wait any longer—they wrote their NetWare client, and it was so good that it continued to be used after the original Novell software came out. In May 1995, thanks to the architecture based on the microkernel, a special "PowerPC edition" of the OS appeared - Windows NT 3.51. According to some reports, its release was delayed due to IBM's inability to stick to the plan to bring this processor to the market. Therefore, the evolution of the PowerPC version went a little further than Windows NT 3.5, which allowed it to become the basis for the next version of the OS.

If until now it was still possible to talk about some similarity between the architectures of Windows NT and even Unix (in some ways infinitely distant, but in some ways very similar to the VMS OS), then with the release of NT 4.0, which introduced the graphics subsystem into core, the last reason for such reasoning has disappeared. In theory, such a decision was an absolutely logical conclusion from the sad experience of trying to integrate the popular Windows 95 window environment into NT. Probably, the idea of repeating the architectural model of X Window - Unix - arose precisely because of the original "server orientation" of NT. However, if there were no problems with the “transplantation” of the graphical shell, then its performance in user mode (i.e., in the form of a regular application) left much to be desired, which is absolutely natural - supporting an abstract output device (be it a bitmap display, a printer, or in general whatever) the Windows graphics subsystem is incommensurably more complex and, accordingly, more demanding on resources than the X Window, which "understands" only raster displays. So, as part of the Windows NT 4.0 kernel, released in July 1996, another module appeared. The revision was called the Shell Update Release (SUR).

The next step was Windows NT 5.0, released on the market in 2000 under the name Windows 2000. The change of "titles" was influenced by marketers and turned out to be, in general, the right decision to reposition this operating system. The work continues to this day, as evidenced by the release of Windows Server 2003.

Battle for Windows The design and implementation of Windows Server belongs to Mark Lucovsky, one of the backers of the corporation's Server OS division. He leads an army of 5,000 developers assigned to seven labs. Another 5,000 programmers work at their workplaces in partner companies, contributing daily their mite to 50 million lines of the resulting Windows Server 2003 OS code.

Every day, a full compilation and assembly of the system is performed to check for operability and identify errors. Lists of detected bugs are sent to development teams. Corrections made must be reported on the bulletin board, which puts them in the queue for inclusion in the main assembly. The server farm involved in compiling the system is constantly being upgraded, however, like many years ago, a complete assembly takes 12 hours of machine time. And this is despite the division of the colossal array of codes into separate independent groups of source texts, organized into tree-like hierarchies.

The quintessence of the development process is the hour-long meetings in the so-called "war room" (War Room), held two or three times daily (at 9.30, 14.00 and 17.00). They are preceded by similar events in the local "battle rooms" of the working groups at 8.00. At the main meeting, corrections of previously discovered errors are discussed and the overall status of the project is determined. In recent days, they have been mainly looking for ways to solve an important problem - renaming Windows .NET Server 2003 to Windows Server 2003. Thousands of names in various modules, and this is at the last moment before the release of the system, which caused a serious headache for developers.

At the meeting, each team should report on the progress of their work, the process of correcting the errors found and the possible consequences of making or not making these amendments. If the problem cannot be solved or it is considered insufficiently important, the bug, according to the original terminology, is "kicked off" in the final release. Missing the morning meeting is equivalent to desertion.

The build starts every day at 4:30 pm and can be delayed until 6:00 pm so that after the third meeting in the "battle room" the latest fixes can be included in the system. The team cannot come to the meeting without a ready solution to the existing problems, otherwise it is better for them not to appear there at all. Each of the seven laboratories has a complete copy of the source code of the system, in which they make their own amendments, compile and check for operability. If everything went smoothly, the new code is merged with the code created by other teams into the main assembly. The problem may lie in the interaction of new code written by different groups. The main assembly is not always successful, sometimes the system is not viable. In this case, as soon as the culprit module is discovered (usually around three or four in the morning), those who wrote it are urgently called to the workplace and do not leave it until the error is corrected. Therefore, programmers must be ready to work 24 hours a day, 6 days a week (six days are introduced as the product release date approaches).

The main principle on which the final stages of testing are built is the use of own products in the project process. Once the system reaches the "first level" of stability, it becomes the main operating system in workgroups. The "second level" is considered to be reached when the OS acquires the ability to function. Only then is it allowed to be used on the Microsoft campus. So it was with the file server under NT, the first use of it was to store the source texts of Windows NT, so they did with the first, and with all subsequent versions of Active Directory.

The product is then submitted for testing to selected JDP (Joint Development Partners) partners. If errors are found, a "volitional decision" is made: leave them in the system and save the sales start date, or postpone the release date and do some improvements. In the latter case, all results are canceled and testing starts from scratch.

It is much more difficult to provide after-sales support. When flaws, security "holes" or the need to add new features to the product are identified, either a local patch or a full-fledged Service Pack has to be formed. Since others already existed before this patch or Service Pack, the new code is tested on many variants of the system, going through all possible combinations of patches and Service Packs. In addition, to carry out a full health check, the corporation maintains separate fragments of its network that operate on older versions of products (for example, Windows Server 2000), where you can "run in" the system in the "field conditions".

How VMS Became WNT

Some wits once joked that if you increment (increase by one) each letter of the name of the Cutler VMS operating system, you get WNT or Windows NT. According to professionals, this is true. Not a preconceived notion based on the fact that the main architects of NT were once the developers of the VMS, but an objective reality.

In fact, NT is the embodiment of radically redesigned, implemented in the C language to achieve better mobility, the architectural ideas of the VMS assembler core, supplemented by the appropriate front-end APIs and new file and graphics subsystems. The commonality of the architectural solutions of the two systems is very high. So, they have the same concepts of processes, priorities (32 levels), management of changing priorities and control over the distribution of processor time between them. But despite the significant similarities, no doubt due to the previous experience of the team of the chief architect - Cutler, NT was originally created as a multi-threaded operating system - this "small" difference alone makes it possible to understand the degree of separation of NT from the "basic" VMS architecture.

Drivers in both operating systems work within the framework of a stack model, each layer of which is isolated from the others, which allows organizing a multi-stage device control scheme. Systems allow swapping of both user processes and system processes, including drivers. The way resources are represented is also similar, both systems treat them as objects and manage them using the Object Manager. NT security, like its underlying Discretionary Access Control Lists or DACLs, traces its lineage back to VMS 4.0.

In 1993, Digital engineers reviewed the specifications for Windows NT and found that it bore a striking resemblance to the experimental Mica operating system that had been created as part of the Prism project. Why such attention to Redmond products? Not from a good life, Digital employees began to study the insides of someone else's system. In 1992, the corporation fell into a protracted peak, money was slipping through its fingers, and sales of the new Alpha processor were slipping. Now in search of salvation, the company's bosses tried to seek help from their worst rival Intel, to which its president, Andrew Grove, refused. In the end, I had to bow to "Gates the Third" and ask for a port of Windows NT under Alpha in exchange for a promise to make NT, to the detriment of VMS, my main operating system. However, having received a pre-release version of NT, Digital's engineers slowly realized that the OS required significantly more RAM than their typical "$5,000 Alpha PC" would hold. NT was clearly not suitable for the mass market of RISC stations, an attempt to stand under the Microsoft flag for Digital (as, indeed, for most other companies) turned out to be a waste of time and money.

The game of "spot 10 differences" between WNT and VMS has paid Digital big dividends. According to one version published at the time in Business Week, instead of openly suing, the president of Digital, with irrefutable evidence of intellectual property infringement in his hands, decided to get more for less. He turned to Microsoft for clarification, which resulted in the signing of a large-scale contract under which Digital became the main network integrator for NT. In addition, in October of the same year, Redmond refused support in Windows NT for both processors competing with Alpha: PowerPC and MIPS. Unfortunately for the Digital management, the alliance was soon destroyed, and the status of "NT network installation services for Microsoft" passed to Hewlett-Packard, which, however, a few years later got another heavy burden of the corporation - the VMS OS.

Despite the fact that the paths of NT and VMS diverged, these operating systems continued a series of peculiar borrowings. In particular, Windows NT received support for clusters only in 1997, while VMS has had it since 1984, and a 64-bit version of Windows appeared even later (VMS migrated to a higher bit depth back in 1996). On the other hand, in VMS 7.0 in 1995, threads were announced at the kernel level, and a Registry-like database and a global event log, similar to the corresponding NT tools, became part of VMS 7.2. Windows Server 2003 is out, let's see what happens next...