Module 23 - Windows NT. The Windows NT operating system is designed to take advantage of the many advances in processor technology. Although primarily run on the Intel architecture, NT was designed to be portable in order to take advantage of whatever promising technologies happened to come along. Key goals for the system included portability, security, POSIX compliance, multiprocessor support, extensibility, international support, and compatibility with MS-DOS and MS-Windows applications. | Lecture Operating system concepts Fifth edition Module 23 - Avi Silberschatz Peter Galvin Module 23 Windows NT History Design Principles System Components Environmental Subsystems File system Networking Programmer Interface Silberschatz and Galvin 1999 Windows NT 32-bit preemptive multitasking operating system for modern microprocessors. Key goals for the system portability security POSIX compliance multiprocessor support extensibility international support compatibility with MS-DOS and MS-Windows applications. Uses a micro-kernel architecture. Available in two versions Windows NT Workstation and Windows NT Server. In 1996 more NT server licenses were sold than UNIX licenses Silberschatz and Galvin 1999 History In 1988 Microsoft decided to develop a new technology NT portable operating system that supported both the OS 2 and POSIX APIs. Originally NT was supposed to use the OS 2 API as its native environment but during development NT was changed t use the Win32 API reflecting the popularity of Windows . Silberschatz and Galvin 1999 Design Principles Extensibility layered architecture. NT executive which runs in protected mode provides the basic system services. On top of the executive several server subsystems operate in user mode. Modular structure allows additional environmental subsystems to be added without affecting the executive. Portability NT can be moved from on hardware architecture to another with relatively few changes. Written in C and C . Processor-dependent code is isolated in a dynamic link library DLL called the hardware abstraction layer HAL . Silberschatz and Galvin 1999 Design Principles Cont. Reliability NT uses hardware protection for virtual memory and software protection mechanisms for operating system resources. Compatibility applications that follow the IEEE POSIX standard can be complied to run on NT without changing the source code. Performance NT subsystems can communicate with one another via .
