Windows NT is still supported

Technical characteristics

However, under the surface of Windows 3.1 there is really a completely new operating system. It is no longer based on DOS, but it can run simple DOS applications, including running several DOS programs in parallel, shielded from one another. Due to a multi-layer architecture, programs can no longer access hardware directly; this was one of the reasons for compatibility problems, but was a prerequisite for increased security and stability.

In contrast to DOS (16-bit), NT now ran with 32-bit, this register widening allowed the significant expansion of the memory space, 4 GB of working memory, of which a maximum of 2 GB per program sounded like a lot at the time. NTFS now allowed the management of 2,000 GB of hard disk space. Preemptive multitasking was also introduced, a central instance - the scheduler - dynamically distributes the computing time to all programs and threads (sub-processes of a program), previous multitasking approaches were mostly cooperative, programs had to forego computing time on their own.

Only Windows programs that were written for the 16-bit versions of Windows have to use cooperative multitasking. These applications share a virtual machine.

Windows NT 3.1 has several layers or. Compatibility levels to run programs, which are divided as follows:

  • WIN32: Programs which were written directly for NT, the different architectures, however, require a respective new translation (source code compatibility).
  • OS / 2 1: Pure text-based console programs can be executed on all processors that are binary-compatible. The versions for Alpha and MIPS lacked this emulation layer.
  • POSIX: source code compatibility, the programs must be recompiled for the respective architecture.
  • WIN16: Programs for DOS-based Windows versions run in a shared virtual DOS machine (VDM), this function is called Windows-on-Windows. On Intel platforms, thanks to direct CPU support, they also run with i386 commands; on RISC systems, there is a purely software-based emulation, which only covers the 80286 command set.
  • DOS: Each DOS application has its own VDM.

Windows NT is an operating system that supports multiple users. Everyone gets their own profile for their personal settings. The user administration is not limited to the assignment of passwords, individual users can be granted write / read / delete rights, and this to a wide variety of resources. In particular, there are user levels with different levels of power, which are usually grouped together in user groups, such as guests, users and administrators.

Windows NT 3.1 supports multiple file systems. In addition to FAT from DOS, HPFS from OS / 2 and a new one called NTFS. This first enables file rights to be assigned. In addition, larger partitions and file names with up to 255 characters are possible with NTFS instead of the usual 8 + 3 characters with FAT.

The particular strength of NT 3.1 is network support. In addition to the general models of workgroups and domains, NT 3.1 can access the following networks: LAN Manager, Novell Netware, DEC Pathworks, Banyan Vines, Unix and SNA Networks. For the first time, the TCP / IP protocol is included, on which all common networks (including the Internet) are based today.