Coherent (operating system)
Coherent is a commercial unixoides operating system of the company Mark Williams Company and was one of the first Unix-like systems for IBM - PC compatible computer.
History
In 1983, the first version of Coherent one of the first Unix-like systems for IBM PC-compatible computer was presented by the Mark Williams Company. Coherent ran on most Intel -based PCs with 286, 386 and 486 processors, but like a "real" Unix, multi-tasking and able to manage multiple users.
Coherent contained a very good printed documentation of over 1,000 pages, consisting of tutorials for the most important Unix programs and a command reference ( man pages ). Coherent in 1990 became famous with the version 3.0, which was first marketed a large area. The special feature of Coherent 3.0 was that it was very inexpensive ( under $ 100 in Germany ), and that it was running on 286 PCs, although the processor only a segment-based memory management unit supported. It was times faster than the then usual MS- DOS 3.1 up to ten.
With Coherent 3.0 it was thus possible for the first time, cost-effective to operate a powerful Unix-like operating system on inexpensive hardware. Coherent contained, as was customary for real Unix systems, a C compiler and the usual Unix development tools such as make or vi editor clone. Thus, one could develop with Coherent without additional software that could be easily port normally on real Unix systems. In Germany and other non- English-speaking countries, however, it proved to be a disadvantage that Coherent 3.0 had no localization. So the keyboard layout was fixed, for example, on American keyboards.
With version 4.0, which was released in May 1992, put Coherent as a minimum a 386 PC ahead. For the binary programs now allow more than 64k. For Coherent 4.0 there was as a paid add-on package is a port of the X Window System.
Coherent is sometimes mistakenly referred to as " Coherent Unix". This is incorrect. Although Coherent based on the specifications of Unix Version 7, but without using the Unix source code, either from Bell Labs or from BSD. Failure to use the source code was a given from the company Mark Williams development policy, compliance with, inter alia, was checked through visits by Dennis Ritchie at the company.
A large part of the operating system was developed by former students of the University of Waterloo wrote: Tom Duff, Dave Conroy, Randall Howard and John George.
The Mark Williams Company went bankrupt in 1995, the version of Coherent last published version was 4.2.10. The reasons for this are manifold. One is that Coherent was overrun by Linux 4.0. Linux also needed a 386, but was free. Linux had TCP / IP network driver, the X Window System and many other software. In addition to that the further development of Linux rapidly went before, during MWC hardly gave updates as drivers for current hardware, the system could be quickly backward and many users angry.